Battery-based intermittent high power source

Abstract

1. A battery-based power supply for powering an intermittently operated load, the power supply comprising: one or more batteries; a voltage step-down converter configured to be connected in series with the batteries and to output a voltage VOUT that is less than a battery voltage V1; a current limiter connected in series with the voltage step-down converter and configured to limit a surge current from the battery while in a current-limit mode and to provide a substantial short circuit while in a non-current-limit mode; and a capacitor tank connected in series with the current limiter to provide a voltage V2 to the load, the capacitor tank configured to be charged to a voltage VICL that is less than VOUT while the current limiter is switched in the current-limit mode and to be charged to a voltage close to VOUT while the current limiter is switched in the non-current-limit mode.

Description

[Technical Field]

[0001] This application claims the benefit of and priority to U.S. Patent Application No. 18 / 166,519, filed February 9, 2023, the entire contents of which are incorporated herein by reference.

[0002] The present disclosure relates to an apparatus and method for powering an electronic device using a battery. [Background technology]

[0003] Many different types of electronic devices can impose specific demands on their power supplies. Lithium and lithium-ion batteries are frequently used to power these devices. Traditional lithium chemistry-based batteries generally have a flat discharge curve and extremely low internal resistance. This makes them advantageous for use in applications with relatively high power requirements, such as cellular modems, RF transceivers, and IoT (Internet of Things) devices, compared to batteries with non-flat discharge curves and high internal resistance, such as alkaline batteries and other non-lithium batteries. Summary of the Invention [Problem to be solved by the invention]

[0004] Therefore, the latter type of battery may have more limited use in electronic devices. [Means for solving the problem]

[0005] The figures illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document. For brevity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity of presentation. Furthermore, reference numerals may be repeated among the figures to indicate corresponding or similar elements. Reference to a previously presented element is implicit without necessarily further recitation to the figure or description in which that element appears. The number of elements shown in the figures should in no way be construed as limiting but is for illustrative purposes only. [Brief explanation of the drawings]

[0006] [Figure 1] 1 is a schematic functional diagram of an exemplary battery power supply (BPS) with a voltage down converter for use with an intermittently operated device, in accordance with one embodiment of the present invention. [Figure 2] 2 is a graph illustrating an exemplary linear characteristic of ground current in the voltage regulator of FIG. 1 in accordance with one embodiment of the present invention. [Figure 3] 2 is an exemplary flow chart illustrating a method of operation of the BPS of FIG. 1 when powering an intermittently operating (switching) device, optionally switching a load between a non-powered state, an optionally low-powered state, and a powered state, in accordance with one embodiment of the present invention. [Figure 4] 4 is a graph of an exemplary charging curve of a capacitor tank voltage in the BPS of FIG. 1, optionally when operating according to the method illustrated in the flow chart of FIG. 3, in accordance with one embodiment of the present invention. [Figure 5] FIG. 1 is a simplified electrical schematic diagram of an exemplary system including a BPS, optionally an IoT system or other type of high power consumption, intermittently operating system, according to one embodiment of the present invention. [Figure 6] FIG. 6 shows an actual real-time measurement graph of the voltage across the capacitive tank in the BPS of FIG. 5 on an oscilloscope, according to one embodiment of the present invention. [Figure 7]4 is a graph illustrating exemplary behavior of battery current over time throughout operation of the BPS of FIG. 1 when operating from an initial state up to and including power-on of the load, optionally according to the method illustrated in the flow chart of FIG. 3, in accordance with one embodiment of the present invention. [Figure 8] 1 is a graph of an exemplary battery current profile with two controlled, time-spaced current pulses produced by a BPS for use with an intermittently operating device, in accordance with one embodiment of the present invention. [Figure 9] FIG. 1 is a schematic functional diagram of an exemplary BPS with voltage up-converters / down-converters for use with intermittently operated devices, in accordance with another embodiment of the present invention. [Figure 10] 10 is an exemplary flow chart illustrating a control unit algorithm used in the BPS of FIG. 9 when powering an intermittently operating (switching) device, optionally switching a load between an unpowered state and a powered state, according to one embodiment of the present invention. [Figure 11] FIG. 1 is a schematic functional diagram of an exemplary battery power supply (BPS) configured for use with a device that operates intermittently in a low power mode (sleep mode), in accordance with another embodiment of the present invention. [Figure 12] 12 is an exemplary flow chart illustrating a control unit algorithm used in the BPS of FIG. 11 when powering an intermittently operating (switching) device, optionally switching a load between a low power supply state (sleep mode) and a power supply state, according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0007] Applicant recognizes that the use of lithium and lithium-ion batteries in IoT devices and other relatively high-power-consumption devices can include several drawbacks, as these types of batteries are hazardous, limited in transport and use, and expensive. Accordingly, Applicant recognizes that there is a need for an apparatus and method for powering a wide class of IoT devices and other relatively high-power-consumption devices without degrading their critical operating characteristics, and for employing batteries, such as alkaline and other batteries, that have widespread availability and lack the drawbacks of lithium-chemistry batteries. Such an apparatus, or hereinafter referred to as a "battery power supply," may, in some embodiments, be suitable for use with any type of "cyclically switched" or "on and off" device, or any device with different load current profiles in different states. Examples of such devices may include cellular 2G / 3G / 4G / 5G modems, RF transceivers, and sensors, among others.

[0008] One aspect of the present invention relates to a battery power supply (BPS) that includes an electronic circuit configured to connect to one or more batteries (hereinafter "batteries") having a non-flat discharge curve and high internal resistance, optionally non-linear, and to replicate the output characteristics of a power source having a battery with a flat discharge curve and low internal resistance (i.e., a lithium battery). The electronic circuit may include analog components, digital components, and control logic configured to adjust operating parameters of the BPS to maintain stability of the BPS over a wide temperature range when connected to an optionally intermittently operating load. The electronic circuit may include a voltage down converter, a pre-charging circuit including a current limiter, a storage capacitor with large-value capacitance and low output impedance, a voltage regulator, and a control unit (controller) for controlling the electronic circuit to provide different current draws to the intermittently operating load. Optionally, the battery and / or the load may be included in the BPS. Optionally, the load may include an intermittently operating IoT device or other relatively high-power switching load. The (intermittently) operating load may, in some instances, include a capacitor.

[0009] An embodiment relates to a battery-based power supply for powering an intermittently operated load, optimized for improved low-temperature performance and extended battery life. The power supply includes one or more batteries; a voltage down-converter connected in series with the batteries and configured to output a voltage VOUT less than the battery voltage V1; a current limiter connected in series with the voltage down-converter and configured to limit a surge current from the battery while in a current-limiting mode and to provide a substantial short circuit while in a non-current-limiting mode; a capacitor tank connected in series with the current limiter to provide a voltage V2 to the load, configured to be charged to a voltage VICL less than VOUT while the current limiter is switched in the current-limiting mode and to be charged to a voltage close to VOUT while the current limiter is switched in the non-current-limiting mode; and a control unit that measures the voltage, controls operation of the voltage down-converter and the current limiter, and activates the load. In some examples, the duration of the charge to the voltage VICL automatically compensates for temperature variations and other device variations. The application of the current limiter enables the device to operate at low temperatures. The partial use of current limiters, the use of intermittent current draw from the battery, the relaxation of the battery prior to load activation, and the application of relaxation periods between battery usage help to extend battery life.

[0010] In some embodiments, the electronic circuit may include two operating states: a first state in which the load is in a non-powered mode, optionally in a low-power consumption mode (which may hereinafter be referred to as a "non-powered mode" or "non-powered state"), and a second state in which the load is in a relatively high-power consumption mode (which may hereinafter be referred to as a "powered mode" or "powered state"). In the first state, the voltage down-converter may initially be set to an off mode associated with a disabled state of the down-converter, and the current limiter may be set to a current-limiting state by the controller. In this first state, the storage capacitor may essentially be disconnected from the battery. When the load is to be switched to the powered mode, the controller may initially set the voltage down-converter to an on mode associated with an enabled state of the down-converter, and apply an initial voltage to the storage capacitor through the current limiter to build up its charge. Upon detecting the voltage on the capacitor and enabling the first charging period, the controller may disconnect the current limiter (i.e., short-circuit or shunt the circuit with a resistance less than that of the circuit) to further increase the voltage on the storage capacitor and initiate a second charging period. The second charging period may be followed by a stabilization period. Upon detecting the increased voltage, and following the optional stabilization period described above, the controller may then turn on the load in power supply mode to draw a high power current from the charged storage capacitor.

[0011] In some embodiments, the electronic circuit may provide battery protection against large current impulses and large inrush currents, and may provide protection from battery depletion by eliminating parasitic self-discharge currents of the storage capacitor while the load is turned off. The electronic circuit may provide a first current surge to a limited (controlled) value in the process of turning on the load, followed by a gradual decrease in current as the storage capacitor initially charges. The electronic circuit may then provide a second, short current surge to the limited (controlled) value when the current limit is disconnected, followed by a relatively long stabilization (relaxation) period with a steady, small (optionally in the milliamp range) discharge current, and then provide full current when the load is powered on.

[0012] It can be appreciated that the BPS of the present invention has several advantageous features in addition to being useful for providing power to devices that typically use batteries with flat discharge curves and low internal resistance. The specific discharge profile, formed by a first regulated surge to a controlled value with decreasing current, followed by a second short surge to the controlled value, followed by a subsequent low discharge current during stabilization, is well suited to the ionic activity characteristics underlying alkaline (and other) chemistry batteries. Furthermore, the electronic circuitry can enable estimation of the battery's condition based on the battery's internal resistance. For example, a dual-pulse test can be used, including as inputs the battery voltage and current (which can be calculated from available data regarding the circuit implementation and voltage measurements) at the end of a first charging period and at the end of a second charging period following stabilization (relaxation). Furthermore, the electronic circuitry can be used as an in-circuit capacitor meter for testing storage capacitors. Furthermore, it can enable self-adaptation to environmental conditions, such as temperature fluctuations. Note that an aluminum electrolytic capacitor with a low temperature rating of -55° C. typically exhibits a capacitance loss of between -10% and -20% when operated at -40° C. As the temperature decreases, the pre-charge current required by the storage capacitor decreases, and therefore the battery may be less stressed despite its high internal resistance.

[0013] In some embodiments, time series data from periodic voltage measurements of the storage capacitor by the controller may be stored (e.g., in the controller) for use during a production test phase (to estimate the actual capacitance of the storage capacitor, which may serve as an indication of the quality of the assembly) or at run time to check its actual condition (which may be useful and important in some cases for devices with operational lives that reach or exceed the operational life of the electrolytic capacitor). This time series data may be used locally by the device or may be transmitted from the device over a communications channel for use by a remote service or application. Note that if the capacitance is to be varied, the data may be useful for adjusting the capacitance accordingly.

[0014] In some embodiments, the BPS of the present invention is integral to a device, and the battery may be built into the BPS, or alternatively, the battery may be separately replaceable. Optionally, the BPS may be a kit that can be retrofitted to an existing device, for example. It should be noted that while the BPS of the present invention is described herein as being operable with batteries having a non-flat discharge curve and high internal resistance, optionally non-linear, those skilled in the art will readily appreciate that the BPS may also be used with batteries having a flat discharge curve, e.g., lithium and lithium-ion batteries, and thus its application is not limited to non-flat discharge curve batteries.

[0015] Referring now to FIG. 1, FIG. 1 is a schematic functional diagram of an exemplary battery power supply (BPS) 100, in accordance with one embodiment of the present invention. The BPS 100 is configured to supply DC power to a load (LOAD) 114 from a battery (BAT) 102, which may have a non-flat discharge curve and high internal resistance, typically associated with alkaline batteries and other types of non-lithium chemistry batteries, or may have other discharge and / or internal resistance characteristics, such as lithium or lithium-ion batteries and other types of batteries. Optionally, the load 114 may be an IoT device or other relatively high-power consumption device, typically powered by a lithium battery. The operating modes of the load 114 may include cyclic switching, optionally on / off states, and / or different load current profiles in different states. The BPS 100 includes a voltage downconverter (VD) 104, a voltage regulator (VR) 106, a current limiter (CL) 108, a capacitor tank (CT) 110, and a control unit (CU) 112. Optionally, the BAT 102 and / or the LOAD 114 may be included in the BPS 100.

[0016] BAT 102 may include multiple batteries connected in series so that the output voltage V1 of the battery pack is generally greater than the voltage V2 required by LOAD 114. As previously mentioned, BAT 102 may include batteries with non-flat discharge curves and relatively high internal resistances, such as alkaline batteries, as well as batteries with other discharge curves and / or other internal resistances, such as lithium metal batteries, lithium ion batteries, or nickel-metal hydride (NiMH) batteries, among others. Alternatively, BAT 102 may be a single battery.

[0017] VDC 104 may include a voltage downconverter (e.g., a buck converter) that downconverts voltage V to voltage V, and is configured to be turned on (enabled) and off (disabled) by CU 112, as described below. Voltage V may be less than V and greater than or equal to V.

[0018] VR 106 may include a low-current voltage regulator that can output a constant voltage V3 as a power source for CU 112, with voltage V3 optionally being less than or equal to V2. During the CU 112's "sleep" period, the output current of VR 106 may be, by way of example, equal to or less than 10 microamperes. VR 106 may include a low-voltage drop linear regulator with a wide input voltage range and low ground current that is linearly dependent on the load current and, optionally, may be in the microcurrent range. For illustrative purposes, FIG. 2 is a graph 150 showing an exemplary linear characteristic of the ground current in VR 106; however, it should be noted that graph 150 may vary according to the type of voltage regulator used. Graph 150 plots ground current in microamperes along Y-axis 152 and load current in microamperes along X-axis 154. The linear dependence is illustrated by line 156, which reflects the increase in ground current as the load current increases. Note that alternatively, VR 106 may involve the use of a switching regulator.

[0019] CL108 may optionally include any type of current limiting circuit that can be controlled by CU 112 to either set the current limit at a predetermined level or to disconnect the current limit (a short-circuit condition such that there is essentially no limit on the current flowing through CL108). The predetermined level of current limit may optionally be determined by the capacity of the capacitive tank, by the particular battery chemistry used, and / or according to the implementation, and may be in the range of tens or hundreds of milliamps. CT 110 may be any type of capacitor, optionally multiple parallel-connected capacitors, with a low equivalent series resistance (ESR), a rated voltage greater than or equal to V2, and a capacitance large enough to supply the relatively large, short current-draw surges required by LOAD 114. LOAD 114 may be, as previously mentioned, an IoT device or generally any other relatively high power consumption device powered by, but not limited to, a lithium battery, for example, any cellular 2G / 3G / 4G / 5G or other modem, RF transceiver, sensor, among many others.

[0020] Note that the selection of CT110 may be determined by the particular consumption profile of LOAD114, and the capacitance of the capacitor tank CT110 may be based on the characteristics of BAT102. Protection of BAT102 from inrush current may be provided by CL108 when VDC104 is turned on and CT110 is fully discharged. Additionally, protection of BAT102 from the self-discharge current of CT110 may be provided when VDC104 is turned off. Thus, the use of CT110 with capacitances ranging from thousands of microfarads to farads and self-discharge currents at milliamp levels or higher may be possible.

[0021] The CU 112 may be part of any device using this BPS 100 power system or may be a specific part of the BPS 100. The CU 112 may include any processor-based device and may include any combination of hardware, software, and firmware. The CU 112 may measure the voltage V1 of the BAT 102 through a monitoring signal 122 and measure the voltage VCT at the CT 110 through a monitoring signal 124. The CU 112 may control the operation of the VDC 104, including enabling it, through a control signal 116, and may further control the operation of the CL 108 through a control signal 118 to set the current limiter to a predetermined current limit level or no current limit level at all. Additionally, the CU 112 may control the operation of the LOAD 114 through a control signal 120 to turn the load on and off. It should be noted that the monitoring signals 122 and 124 and the control signals 116, 118, and 120 may be implemented using any one or combination of analog and digital signals, including appropriate circuitry, including transmission buses, as needed.

[0022] The CU 112 may implement the feedback required to maintain BPS operation despite temperature and component tolerance variations. The CU 112 may further adjust operating parameters based on the type and requirements of the LOAD 114 and / or the battery charge level. The CU 112 may measure the voltage VCT of the CT 110 using the monitoring signal 124 and, in response, control the operation of the VDC 104 and the CL 108 via control signals 116 and 118, respectively. The CU 112 may measure the voltage V1 of the BAT 102 using the monitoring signal 122, measure the voltage VCT of the CT 110 using the monitoring signal 124, and control the operation of the CL 108 using the control signal 118, thereby determining the battery charge level by indirectly measuring the battery's internal resistance.

[0023] 3, which is an exemplary flow chart 300 illustrating a method of operation of a BPS when powering an intermittently operating (switching) device, according to one embodiment of the present invention. For ease of understanding, flow chart 300 will be described with reference to BPS 100 and components therein in FIG. 1.

[0024] At 302, the BPS 100 may be in an initial state, the VDC 104 may be turned off (disabled), the CL 108 may be in a current limit mode (at a predetermined current limit level), the CT 110 may be discharged, the VR 106 may be in an always-on state so that it is continuously operable and supplies power to the CU 112, and the LOAD 114 may be in an unpowered state.

[0025] At 304, the CU 112 may measure the voltage V1 through the monitor signal 122. The CU 112 may be configured to measure the voltage V1 at predetermined time intervals or continuously.

[0026] At 306, CU 112 may determine whether the measured voltage V1 exceeds the minimum input voltage VDCin required by VDC 104 (i.e., whether the battery voltage under light load is sufficient to initiate the voltage down converter). If the minimum input voltage VDCin is not exceeded, it returns to step 302. Note that as part of returning to step 302, troubleshooting efforts may be performed to determine whether BAT 102 may have failed (or become depleted).

[0027] At 308, in response to the determination that voltage V1 > VDCin, CU112 may turn on VDC104 with control signal 116 that can act as an enabling signal. The input signal is enabled at a point well before the expected operation of LOAD114 so that CT110 can be fully charged to power LOAD114. VDC104 may output voltage VOUT that can be applied to CL108. Note that CL108 may be in current limit mode from step 302 and, together with the actual capacitance of CT110, may define the time constant (delay) required to charge the capacitor tank to voltage VCT = VICL. Further, at step 312, determined by the operation method of BPS, there may be a threshold voltage value VICL that may be less than V OUT Note that there may be a threshold voltage value VICL that may be less than V. An exemplary charging curve of CT110 will be further described below with reference to FIG. 4, where the V ICL voltage level is referenced as dotted line 410. Based on the above, it can be understood that the following voltage relationship, V1 > VOUT > VICL, may exist in BPS.

[0028] At 310, following the activation of VDC104, CU112 may repeatedly, or alternatively continuously, measure voltage VCT in CT110. The measurement may be performed by monitoring signal 124 and may be implemented together with step 308.

[0029] At 312, CU112 may compare each measurement of voltage VCT with voltage VICL. VICL may be the expected threshold voltage value to be reached while the CL108 current limiter is enabled. VICL may be less than V OUT If VCT < VICL and the threshold voltage has not been reached, proceed to optional 314 or directly to 316. If VCT ≥ VICL, proceed to 318.

[0030] At optional 314, CU112 may accumulate each measurement of voltage VCT for later use in the production test phase as further described below.

[0031] At 316, CU 112 may implement a delay that may be less than the delay introduced by the RC combination of CL 108's resistance and CT 110. The amount of this delay may be determined based on the time constants of CL 108 and CT 110 and the tolerance in detecting voltage equality across CT 110 and at threshold V ICL. For example, if it is known that a 0.1 V error in the comparison V CT ≥ V ICL is acceptable and that the minimum time to charge CT 110 by 0.1 V may be Tmin based on the given time constants of CL 108 and CT 110, the specified delay may be set to Tmin.

[0032] At 318, in response to CU 112 measuring through the monitoring signal that V > V, the control unit may enable CL 108 (release current limit, short circuit state) through control signal 118. The voltage V may increase and approach V (not equal, because despite a theoretical short circuit, there is finite resistance in any possible implementation of CL 108). Note that CT 110 may not need to be fully charged at this point; additional charge may be provided by a surge current due to the short circuit in CL 108.

[0033] At 320, in response to an expected jump in VCT following the activation of CL 108 at 318, CU 112 may implement a delay to allow stabilization of both VCT and ions in BAT 102. In a practical implementation, the value of this stabilization delay may be tens of milliseconds and may be optimized in a practical manner based on experimentation with battery chemistries required.

[0034] At 322, following an optional stabilization delay, CU 112, the control unit, may activate control signal 120 to activate (enable, turn on) LOAD 114. With V2 applied to its input, LOAD 114 may draw the necessary current needed for operation from the charged capacitor tank CT110 and VDC104 outputs.

[0035] At 324, the LOAD 114 may remain in an activated state (enabled, turned on) until the CU 112 deactivates (disables, turns off) the LOAD 114 via the control line 120. The CU 112 may optionally wait for and receive an external command (signal) that causes the CU 112 to deactivate the LOAD 114. While the LOAD 114 is operating, the LOAD 114 is powered by the CT 110. The CU 112 may maintain the state of the control output while waiting for an external command (signal) to deactivate the load.

[0036] At 326, the BPS may return to step 302, which reinitializes the state of the components of the BPS.

[0037] Flow chart 300 is shown including steps 302-326. It should be noted that steps 302-326 may be repeated for any operation that may require switching the operation of LOAD 114 between an unpowered state and a powered state. It should also be noted that one skilled in the art may practice the teachings of the method described by flow chart 300 using more or fewer steps and / or a different sequence of steps.

[0038] Note that during operation of the BPS 100, the BAT 102 may experience several variable conditions. Initially, when CT 110 begins to charge, the BAT 102 may initially experience a relatively sudden surge of current, the amplitude of which may be determined by the value of the resistor in CL 108, the actual capacitance of CT 110, the remaining charge in the storage capacitor tank 110 (if the capacitor is not fully discharged), and the ratio of V1 to VOUT. The BAT 102 may experience a strong discharge current that decreases over the charge cycle while CL 108 is in current-limit mode. When CL 108 is disconnected (current limit removed), the BAT 102 may experience a second sudden surge of current. Following that surge, a battery stabilization (relaxation) period may be initiated. During this period, the battery discharge current may be small, but may be greater than that in step 302, since the current may be equal to the sum of the operating current of CU112, the parasitic current drawn by LOAD114 in the off state, the self-discharge current of CT110, the current drawn by VR106 in the on state, and the current drawn by VDC104.

[0039] In some embodiments, the BPS 100 turning off power to the LOAD 114 may be initiated by a transfer of control to a subroutine executable by the CU 112. The CU 112 may power off the LOAD 114 and then sequentially disable the VDC 104, either without a delay or with a required delay if required by the LOAD 114. As a result, the CT 110 capacitor tank may be disconnected from the battery BAT 102, and its leakage current will not discharge the battery BAT 102.

[0040] 4, which is a graph 400 of an exemplary charging curve of the CT 110 when operating optionally according to method 300, in accordance with one embodiment of the present invention. Graph 400 plots VCT on the y-axis 402 versus T (time in msec) on the x-axis 404. As shown, the charging curve 406 of the CT 110 may rise exponentially from VCT=0 at T=T0 (VDC 104 is turned on and outputs VOUT) to VCT=VICL 410 at T=Ton 412, with a time constant determined by the resistance of CL 108 and the capacitance of the CT 110. At Ton 412, release of current limit causes VCT to increase to approach VOUT at time T=TOUT 414, an increase indicated by Vinc 416, and VCT=VICL 418 at T=Tout.

[0041] Reference is now made to FIG. 5, which is a simplified electrical schematic diagram of an exemplary system 500, optionally an IoT system, or other type of relatively high power consumption, intermittently operating system, including a BPS 501, in accordance with one embodiment of the present invention. System 500 may further include a non-flat discharge, high internal resistance multi-cell battery BTI 502 and a connected load U2 512. Alternatively, BTI 502 may include one or more batteries with flat discharge curve characteristics, such as, but not limited to, lithium batteries or lithium-ion batteries. Optionally, BPS 501, BTI 502, and U2 512 may be functionally similar to BPS 100, BAT 102, and LOAD 114 in FIG. 1 .

[0042] U1 504 with feedback resistors R1 505 and R2 503 can be any common high-speed buck DC / DC converter implementing VDC 104 (non-essential implementation details are omitted). The R1 505 and R2 503 analog feedback circuit can be used to evaluate the performance of U1 504 by periodic or real-time (comparator-based) measurement of U1's FB voltage by controller U3 512. During normal operation of U1 504, the FB voltage can be equal to the voltage of U1's internal reference voltage source, known from the manufacturer's documentation, which can be used to check U1 operability. U1 not only acts as a voltage down converter, but also as a control switch with an enable / disable state controlled by U3 512's Buck_EN signal (control signal 116 in FIG. 1).

[0043] U4 506 may implement VR106 in FIG. 1 and may include an LDO (low-dropout regulator). SW1 508 and RCL 509 may implement CL108 in FIG. 1. SW1 508 may be implemented using any electronically controlled switch, for example, a P-MOSFET, that has a low resistance in a closed state. SW1 508 may be controlled by a CL_SW signal (control signal 118 in FIG. 1). RCL 509 may be a current-limiting resistor. In combination with U1 504 and capacitor tank CET 510 (CT110 in FIG. 1), the current limiter circuit may form a capacitor pre-charge system in which U1 and SW1 508 may form a two-switch series combination. Note that RCL 509, along with feedback resistors R1 505 and R2 503, may act as a "bleeder" circuit for CET 510 when U1 is disabled.

[0044] U2 514 may be any possible intermittently activated load (LOAD 114 in FIG. 1) with an EN (enable) control signal input that may enable it to be turned on or off. U3 512 may be any controller suitable for controlling the operation of BPS 501, as described herein below and previously with reference to the operation of BPS 100 and CU 112 in FIG. 1.

[0045] Note that Vin and Vout at U1 504 correspond to V1 and Vout, respectively, in Figure 1. Furthermore, I and Q at U4 504 correspond to V1 and V3, respectively, in Figure 1. Furthermore, ADC_CET corresponds to VCT in Figure 1, and Vpow corresponds to V2 in Figure 1.

[0046] The following is a description of an exemplary operation of system 500, according to one embodiment of the present invention. The description may reflect some or all of the steps shown in flow chart 300 in Figure 3. Note that as described in flow chart 300, U1 504 is in a disabled state, SW1 508 is open (RCL 509 provides current limiting), and U4 506 is activated (continuously on).

[0047] To turn on U2 514, controller U3 first enables U1 504. After successfully enabling U1 504, U3 ADC_CET provides periodic measurements (or samples) of the voltage VCT on capacitor tank CET 510. When SW1 is in the open state, capacitor tank CET 510 charges through resistor RCL 509. When VCT > VICL, U3 CL_SW closes SW1 508, shorting RCL 509 and increasing the voltage VCT until it approaches VOUT. After a stabilization delay, U3 512 activates LOAD_EN to enable U2 514.

[0048] Referring now to FIG. 6, FIG. 6 shows an actual real-time measurement graph 600 of the VCT in the BPS 501 on an oscilloscope, according to one embodiment of the present invention. The top waveform 602 is the voltage on the capacitor tank CET 510, and the bottom waveform 604 is the Buck_EN control signal. A short, needle-like negative voltage drop 606 across the capacitor tank CET is the visible response to the load being turned on (by the LOAD_EN signal). The time interval between the controllable inrush battery current spike 608 (or voltage across the capacitor tank CET) and the initial needle voltage drop 606 is the battery relaxation period.

[0049] As previously described, an electronic circuit can be used to estimate the battery's internal resistance by applying the dual-pulse method. Referring again to FIGS. 4 and 5, at time Ton, switch SW1 508 may be open, and capacitor tank CET 510 may be charging through resistor RCL 509. Because U1 504 is a voltage source, its output voltage Vout may be independent of the load current (within the normal operating range). Furthermore, the voltage VCT on capacitor tank CET 510 may be measured, and thus the voltage drop across resistor RCL 509 may be determined (Vout - VCT). Since the resistance of RCL 509 is known, the current through that resistor may be calculated by U3. Using U1's conversion factor N (Vin / Vout) (which may optionally be set by resistors R1 and R2), the battery current at instant Ton may be calculated by U3 as IBT1 = IRCL / N. Following the closing of switch SW1 508, the pre-charge voltage on capacitor tank CET510 at time Ton may be known, as may the voltage VCT at time Tout (there may be a small voltage drop across SW1 508), which should be substantially equal to U1 Vout. The capacitance of capacitor tank CET510 may be known by design, or it may be estimated in real time using available information (as previously described), in which case the inrush charge current value of capacitor tank CET510 may be calculated and the resulting value converted to battery current given the known conversion factor in U1 504.

[0050] Referring now to FIG. 7, FIG. 7 is a graph 700 of exemplary behavior of BAT 102 current 720 while turning on and powering LOAD 114, optionally when operating according to method 300, in accordance with one embodiment of the present invention. Graph 700 plots BAT 102 output current I (current in amperes A) on y-axis 706 versus time t (time in milliseconds) on x-axis 707. Until time 701, the BPS 100 and LOAD 114 may be in a low-power state (optionally sub-mA). At time 701, which may relate to step 308, the discharged capacitor tank CT110 is connected to the output of a disabled (current-limiting) current limiter. This may result in a near-instantaneous rise in battery current 720 to current limit 708, as shown. Battery current 720 may then decrease in accordance with the increasing voltage across capacitor tank CT110 (as shown during time interval 704). Time point 702 may be associated with step 318, where current limiter CL108 may be enabled and a second, very brief surge in battery current 720 may occur (due to the low output impedance of VDC 104). Time interval 705 may be a stabilization (relaxation) delay associated with step 320. Time point 703 may be associated with step 322, where LOAD 114 may be turned on and battery current may spike to the level of consumption of LOAD 114.

[0051] Note that the value of first battery current surge 708, the value of battery current 710 at time 702, and the value of second battery current surge 709 may each be individually controllable. Furthermore, note that the value of first battery current surge 708 and the value of second battery current surge 709 may not be equal, and the particular values ​​of these current surges may be determined experimentally to optimize the operation of the entire BPS as a whole. Furthermore, note that time interval 705 may be controllable. Note that time interval 704 is, by design, dependent on the capacity of CT 110, and therefore battery current 710 is independent of the capacity of CT 110. Similarly, second current surge value 709 is independent of the actual capacity of CT 110. It should be noted that time interval 705 is more related to the process of relaxation (or stabilization) of charge carriers (ions) in BAT102 than to the process of voltage stabilization for the capacitor tank, since the duration of this interval is much longer than the duration of the second surge of current, which may be measured on the order of tens (or even hundreds) of milliseconds, and which may correspond to the mobility of the battery's chemical charge carriers.

[0052] In some embodiments, the BPS described above with reference to Figures 1-7 may be modified to allow for the use of a voltage up converter, or even a hybrid converter such as both a voltage down converter and a voltage up converter, e.g., a buck-boost converter. According to some embodiments, the modifications allow for the use of any type of battery source, regardless of whether the battery source voltage is greater than, equal to, or less than the voltage required by the load, based on the implementation in which the battery current behavior can be controlled, as exemplarily shown in Figure 7.

[0053] According to some embodiments, controlling battery current behavior may include creating a battery current profile having two time-spaced current pulses whose amplitudes are controlled and whose time interval between the current pulses is an automatically generated delay based on the real-time capacitance of the capacitor tank. This may be particularly advantageous because it not only allows the BPS to be used with any type of battery source, regardless of load voltage requirements, but also provides BPS operation that is substantially unaffected by changes in capacitor tank parameters (i.e., due to environmental conditions, including temperature) or component aging. An example of such a current battery profile is shown in FIG. 8, which is a graph 800 of an exemplary controlled battery current profile including two time-spaced current pulses 802 and 804 with controlled amplitudes CSP1 and CSP2, respectively, according to one embodiment of the present invention. The time delay between the two current pulses 802 and 804 may be provided by the time separation between T1 and T2.

[0054] Before describing graph 800 in more detail, as previously mentioned, BPS 100 can be modified to allow operation with a battery having a voltage greater than, equal to, or less than that required by the load. This can be achieved by controlling the behavior of the battery current profile to include two time-spaced current pulses of controlled amplitude with a time interval (delay) between the pulses that is automatically generated based on the capacitance of the capacitor tank. According to one embodiment of the present invention, such a modified BPS 100 is illustratively shown in FIG. 9 as BPS 900 and described herein below.

[0055] In some embodiments, the BPS 900 may include a configuration similar to that of the BPS 100 and may include a voltage converter (VCON) 904, a voltage regulator (VR) 906, a current limiter (CL) 908, a capacitor-tank (CT) 910, and a control unit (CU) 912. The BPS 900 may be configured to supply DC power from a battery (BAT) 902 to a load (LOAD) 914. The BAT 902 may be similar to the BAT 102, except that the battery voltage V1 may be greater than, less than, or equal to the voltage V2 required by the load 914.

[0056] VCON 904 may include a voltage converter for converting voltage V1 to voltage VOUT (substantially equal to V2) and is configured to be turned on (enabled) and off (disabled) by CU 912. VCON 904 may be a downconverter (e.g., a buck converter) when V1 is greater than V2 and / or an upconverter when V1 is less than V2. Optionally, VCON 904 is a buck-boost converter that can automatically switch between boost and buck modes depending on the required load voltage V2 of LOAD 914. Note that VCON 904 may also provide a voltage VOUT substantially equal to V1 when V1 is within a range substantially "equal" to the required load voltage V2.

[0057] VR906 may be functionally similar to VR106, which is configured to meet the power requirements of CU912. CU912 may be functionally similar to CU112, which is configured to control components in BPS900 according to programmed instructions and as needed to execute the algorithms described in Figure 10 related to the operation of BPS900. CT910 may be functionally similar to CT110, which is configured to charge the capacitor tank voltage VCT to a value that can help provide the required load voltage V2.

[0058] CL908 may include any type of controllable current limiter configured to switch between two current limit levels (ILMT1 and ILMT2). ​​The values ​​of ILMT1 and ILMT2 may be determined by the chemistry and capacity of BAT902. For example, ILMT1 may be a lower current limit level (i.e., greater current flow through CL908) and may range from tens of milliamps to hundreds of milliamps, while ILMT2 may be a higher current limit level (i.e., less current flow through CL908). CL908 may include a discharge path to provide automatic discharge of CT910 when LOAD914 is turned off.

[0059] Control signals 916, 918, and 920 may be functionally similar to control signals 116, 118, and 120, respectively. Monitor signals 922 and 924 may be functionally similar to monitor signals 122 and 124, respectively.

[0060] Next, returning to graph 800, the battery output current IBAT (current in units of amperes A) on the y-axis 806 versus the time T (time in units of msec) on the x-axis 808 is plotted there. At time T < T1, BPS900 can be in a low power state (optionally sub mA), LOAD914 can be in an off state, and thus, IBAT is substantially equal to 0 (the minimum current output required to power VR906 and CU912), CT910 is in a discharging state, and VCT = 0. At time T1, VDC906 is activated and there is a flow of IBAT into the discharged capacitor tank CT910, and that inrush current is indicated by a nearly instantaneous rise 810 of IBAT up to a pre-set value ILMT1 = CSP1 at CL908. IBAT can then decrease exponentially as the voltage of the capacitor increases until the capacitor tank CT910 reaches a predetermined threshold voltage VICL which is less than V2 at time T = T2 812. At time T = T2, CL908 is set to a predetermined higher current limit ILMT2 = CSP2, causing a second nearly instantaneous rise 814 of IBAT up to CSP2 to substantially charge CT910 to VCT = VOUT = V2, after which an exponential decrease 816 of IBAT continues as the capacitance tank reaches full charge.

[0061] To fully describe the operation of BPS900, which includes controlling the behavior of the battery current IBAT, reference is next also made to FIG. 10. FIG. 10 is a flow chart 1000 illustrating an exemplary algorithm including various steps performed by CU912 in BPS900 to intermittently provide power from BAT902 to LOAD914, according to one embodiment of the present invention.

[0062] At 1002, BPS900 can be in an initial state. VCON904 can be turned off (deactivated), VR906 can be in an always-on state so that it is continuously operable and powers CU912, CT910 can be discharged (VCT = 0), and LOAD914 can be in a non-powered state.

[0063] At 1004, the CU 912 may measure the voltage V1 through the monitor signal 922. The CU 912 may be configured to measure the voltage V1 at predetermined time intervals or continuously.

[0064] At 1006, CU 912 may determine whether the measured voltage V1 exceeds the minimum voltage VDCin (i.e., whether the battery voltage under light load is sufficient to initiate the voltage down converter). If the minimum voltage VDCin is not exceeded, it returns to step 1002. Note that as part of returning to step 1002, troubleshooting may be performed to determine whether BAT 902 may have failed (or become depleted). If the minimum voltage VDCin is exceeded, it continues.

[0065] At 1008, in response to determining that voltage V1>VDCin, CU 912 may set ILMT1 at CL 908. Referring to Figure 8, CU 912 may set ILMT1=CSP1. CU 912 may set ILMT1 at CL 908 through control signal 918.

[0066] At 1010, CU 912 may turn on VCON 904 via control signal 916, which may serve as an enable signal. VCON 904 may be a boost converter, a buck converter, or a buck / boost converter, depending on the voltage output of BAT 902 and the voltage load requirement V2 of LOAD 914. In response to turning on VCON 904, the voltage VCT of CT 910 charges to a value (inrush current IBAT is limited such that charging of CT 910 is limited) that is less than VOUT (and V2) and is limited by the selection of IMT1 = CSP1 in CL 908. Referring again to FIG. 8, the inrush IBAT charging CT 910 is represented by the nearly instantaneous rise 810 of IBAT to the preset value CSP1.

[0067] At 1012, CU912 can measure the voltage VCT of CT910. The voltage VCT can be measured periodically in a period that is significantly less (e.g., 50 to 100 times less, or significantly less than the time constant of the capacitor charging circuit) than the time required to fully charge the capacitor tank CT910 at a selected level of the charging current. Alternatively, the measurement can be performed continuously. The measurement can be performed by the monitoring signal 924.

[0068] At 1014, CU912 can compare each measurement of the voltage VCT with a predetermined threshold voltage VICL. VICL can be the expected threshold voltage value to be reached while CL908 is set to ILMT1. VICL can be less than VOUT. If VCT < VICL and the threshold voltage has not been reached, proceed to 1012. If VCT ≧ VICL, continue.

[0069] At 1016, in response to CU912 measuring that VCT≧VICL through a monitoring signal, the control unit may set ILMT2 at CL108 through control signal 918 (referring to FIG. 8, ILMT2 = CSP2). The voltage VCT may increase and approach VOUT (not equal to VOUT because there is resistance in both current limit modes of CL908). CT110 may be fully charged at this point, and additional charging is provided by the surge current due to the change in the current limit level at CL108 from ILMT1 to ILMT2. VOUT may become substantially equal to V2, and since the capacitor tank CT910 is charged to a voltage significantly lower than V2, VICL < V2, at the moment of switching CL908 from ILMT1 to ILMT2 corresponding to a higher current limit setting of VCON904, note that a large current (equal to, for example, the maximum current drawn by LOAD914) may be drawn. This may result in a short burst of current (FIG. 8, second pulse 804) that fully charges the capacitor tank CT910. The amplitude of the current spike may be determined by the charge value of the capacitor tank CT at that point. This charging of the capacitor tank CT is determined by the value of the threshold voltage VICL and the amplitude CSP2 of the second controlled pulse of current.

[0070] In some examples, at 1018, CU912 measures the voltage VCT at CT910 to determine if it has reached the required load voltage V2. The measurement may be performed by monitoring signal 924.

[0071] In some examples, at 1020, CU912 compares the measured voltage VCT with the required load voltage V2. If VCT is significantly less than V2, it returns to 1018. In other cases, it continues. Note that as a result of IBAT decreasing exponentially by exponential decay 816 as shown in FIG. 8, CT910 continues to charge and VCT continues to increase towards VOUT.

[0072] At 1022, in response to an expected jump in VCT following the setting of ILMT2 in CL 908, CU 912 may implement a delay to allow stabilization (relaxation) of both VCT and the ions in BAT 902. In a practical implementation, the value of this stabilization delay may be tens to hundreds of milliseconds, and may optionally be optimized in a practical manner based on experimentation with a battery of the required chemistry.

[0073] At 1024, following a stabilization delay, CU 912 may activate control signal 920 to activate (enable, turn on) LOAD 914. With V2 applied to its input, LOAD 914 may draw the necessary current needed for operation from the charged capacitor tank CT910 and VCON904 output.

[0074] At 1026, the LOAD 914 may remain in an activated state (enabled, turned on) until the CU 912 deactivates (disables, turns off) the LOAD 914 via the control line 920. The CU 912 may optionally wait for and receive an external command (signal) that causes the CU 912 to deactivate the LOAD 914. The CU 912 may maintain the state of the control output while waiting for the external command (signal) to deactivate the load. Note that in some embodiments, turning off the power supply to the LOAD 914 may be initiated by a transfer of control to a subroutine executable by the CU 912. The CU 912 may power off the LOAD 914 and then sequentially disable the VCON 904, either without a delay or with a required delay if required by the LOAD 914. As a result, the CT 910 capacitor tank may be disconnected.

[0075] At 1028, following the deactivation of LOAD 914, CT 910 may discharge through CL 908.

[0076] At 1030, the BPS may return to step 1002, which reinitializes the state of the components of the BPS.

[0077] Shown is a flow chart 1000 including steps 1000-1030. It should be noted that steps 1000-1030 may be repeated for any operation that may require switching the operation of LOAD 914 between an unpowered state and a powered state. It should also be noted that one skilled in the art may practice the teachings of the algorithm described by flow chart 1000 using more or fewer steps and / or a different sequence of steps.

[0078] Note that not all intermittently operating devices are constantly powered on and off, and some may have a sleep mode in which very low power is consumed by the device instead of having to be completely powered off. In some embodiments, the BPS 900 illustrated in FIG. 9 may be modified to work with intermittently operating devices that operate in a sleep mode.

[0079] 11, which is a simplified functional diagram of a BPS 1100 configured for use with a device that operates intermittently in a low-power mode (sleep mode) in accordance with another embodiment of the present invention. The BPS 1100 may be similar to the BPS 900, except that the BPS 1100 is modified to provide DC power from the BAT 902 to a LOAD 1114, where the load is configured to be switched between a high-power operating mode and a low-power sleep mode in addition to, or as an alternative to, an off mode in which the load is turned off completely.

[0080] Similar to BPS 900, BPS 1100 may include VCON 904, VR 906, CL 908, and CL 910. Similar to BPS 900, BPS 1100 may include control signals 916, 918, and 920 and monitor signals 922 and 924. In addition to BPS 900, BPS 1100 may include an optional second voltage regulator VR2 1107, first switches SW1 and SW2, and a control unit CU1112, which may be functionally similar to CU 912, configured to control components in BPS 1100 according to programmed instructions and as needed to execute the algorithms described in FIG. 12 associated with the operation of BPS 1100. Additionally, there are control lines 1125, 1127, and 1129.

[0081] The optional VR2 1107 can be any suitable type of voltage regulator with very low load losses for very low load currents to generate a voltage equal to the voltage required by LOAD 1114 in sleep mode. VR2 1107 can be used when the voltage output of VR906 is not suitable to supply the voltage required by both CU1112 and LOAD 1114 (requiring different supply voltages). Optionally, the discharge current of CT910 can be used when the current consumption of LOAD 1114 in sleep mode is less than the discharge current. In this case, CT910 does not discharge through CL908 when LOAD 1114 is powered off.

[0082] Control line 1125 may serve to enable CU1112 to activate sleep mode in LOAD 1114 (and may also serve as a monitor line by the control unit to receive confirmation that the load has entered sleep mode). Control line 1127 may enable CU1112 to control the operation of SW1, which is closed when LOAD 1114 is to be powered on or is in the on state, and is open when the load is in sleep mode. Control line 1129 may enable CU1112 to control the operation of SW2, which is open when LOAD 1114 is to be powered on or is in the on state, and is closed when the load is in sleep mode.

[0083] Referring now to FIG. 12, FIG. 12 is an exemplary flow chart illustrating a control unit algorithm used in BPS1100 when powering an intermittently operating (switching) device, optionally switching a load between a low power supply state (sleep mode) and a power supply state, in accordance with one embodiment of the present invention.

[0084] Referring now to FIG. 12, FIG. 12 is a flow chart 1200 illustrating an exemplary algorithm including various steps performed by the CU 1112 in the BPS 1100 to provide intermittent power from the BAT 902 to the LOAD 1114, in accordance with one embodiment of the present invention.

[0085] At 1202, the BPS 1100 may be in an initial state. All components are in a state similar to that of the BPS 9000 at step 1002 in the algorithm 1000 (see FIG. 10). Additionally, SW1 is in a closed state and SW2 is in an open state. The optional VR2 1107 may be powered on, as may VR906.

[0086] At 1204, the CU 1212 may perform steps similar to steps 1004-1024 of the CU 912 in the algorithm 1000, but with the BPS 1100.

[0087] At 1206, LOAD 1114 may remain in an activated state (enabled, turned on) until CU 1212 invokes sleep mode in LOAD 1114 via control line 1125. CU 1212 may optionally wait for and receive an external command (signal) that causes CU 1212 to activate sleep mode in LOAD 1114. CU 1212 may maintain the state of the control output while waiting for the external command (signal) to invoke sleep mode in the load. Note that in some embodiments, activating sleep mode in LOAD 1114 may be initiated by a transfer of control to a subroutine executable by CU 1212.

[0088] At 1208, the CU 1212 may command the LOAD 1114 to enter sleep mode. The command may be transferred over control line 1125.

[0089] At 1210, CU 1212 may turn off (disable) VCON 904. CU 1212 may disable VCON 904 in response to receiving a sleep OK signal from LOAD 1114 confirming that the load has entered sleep mode. Alternatively, CU 1212 may disable VCON 904 after a predetermined period of time following invoking sleep mode over control line 1125. Optionally, the predetermined period of time may be related to a time delay of LOAD 1114 between receiving control signal 1125 and entering sleep mode.

[0090] At 1212, immediately after disabling VCON 904, CT 910 may discharge current (which may generally be in the microampere range) through SW1 to power LOAD 1114 in sleep mode. Optionally, the discharge current from CT 910 may be leakage current from the capacitor tank.

[0091] At 1214, CU 1212 may open SW1 via control line 1127, disconnecting CT910 from LOAD 1114, and close SW2 via control line 1129, connecting VR2 1107 to the load.

[0092] At 1216, power to the LOAD 1114, which is in sleep mode, may be supplied by VR2 1107, allowing the load to remain in sleep mode until woken up.

[0093] In 1218, the CU 1212 starts the LOAD 1114 (when needed) in preparation for powering on the load. In this step, the CU 1212 closes SW1 and opens SW2. The BPS 1100 then returns to power-on mode (step 1024).

[0094] Additional examples:

[0095] Example 1 is a battery power supply for powering an intermittently operating load, comprising: a voltage down converter configured to be connected in series with the battery and to output a voltage VOUT that is less than the battery voltage V1; a current limiter connected in series with the voltage down converter and configured to provide a voltage drop in a current limited mode and to provide a substantially short circuit in a non-current limited mode; a capacitor tank connected in series with the current limiter to provide voltage V2 to the load, the capacitor tank being configured to charge to a voltage VICL less than VOUT while the current limiter is switched into a current-limiting mode, and to charge to a voltage substantially equal to VOUT when the current limiter is switched into a non-current-limiting mode; a controller configured to sense a battery voltage (V1) and a capacitor tank voltage (VCT), and configured to switch the voltage down converter between an off state and an on state, switch the current limiter between a current limiting mode and a non-current limiting mode, and switch the load between an off state and an on state; The present invention relates to a battery power supply comprising:

[0096] Example 2 includes the subject matter described in Example 1, and optionally, the controller switches the voltage down-converter from an off state to an on state in response to receiving a signal from a signal source external to the battery power supply.

[0097] Example 3 includes the subject matter described in Example 1, and optionally, the controller switches the voltage down-converter from an off state to an on state in response to the battery voltage V1 being equal to or greater than a turn-on voltage VDCin of the down-converter.

[0098] Example 4 includes the subject matter described in Example 1, and optionally, the controller switches the current limiter from a current-limiting mode to a non-current-limiting mode when it detects that VCT equals or exceeds a threshold voltage of VICL less VOUT.

[0099] Example 5 includes the subject matter of any one or more of Examples 1 to 4, and optionally, the controller activates the load in response to the capacitor tank being charged to a voltage substantially equal to VOUT.

[0100] Example 6 includes the subject matter of Example 5, optionally, wherein the capacitor tank voltage VCT is held at a voltage substantially equal to V2 for a period of time following the current limiter being switched to a non-current limiting mode prior to the controller activating the load.

[0101] Example 7 includes the subject matter of any one or more of Examples 1-6, optionally including a voltage regulator for providing regulated power to the controller.

[0102] Example 8 includes the subject matter of any one or more of Examples 1 to 7, optionally wherein the battery includes a non-flat discharge curve and a relatively high internal resistance compared to a battery including a flat discharge curve.

[0103] Example 9 includes the subject matter of any one or more of Examples 1 to 8, and optionally, the battery includes one or more alkaline batteries, one or more non-lithium batteries, one or more lithium batteries, or one or more lithium-ion batteries.

[0104] Example 10 includes the subject matter of any one or more of Examples 1 to 7, optionally, the battery includes a flat discharge curve and a relatively low internal resistance.

[0105] Example 11 includes the subject matter of any one or more of Examples 1 to 8, optionally wherein the battery is integral with the battery power supply.

[0106] Example 12 includes the subject matter of any one or more of Examples 1-11, and optionally, the intermittently operating load comprises an Internet of Things (IoT) device.

[0107] Example 13 includes the subject matter of any one or more of Examples 1 to 12, optionally wherein the controller is external to the battery power supply.

[0108] Example 14 is a method of providing DC power to an intermittently operating load from a battery, the method comprising: applying a voltage V1 from a battery to a series-connected voltage down converter, the voltage down converter configured to output a voltage VOUT that is less than V1; applying a voltage V to a current limiter connected in series with the voltage down converter, the current limiter configured to provide a voltage drop in a current limited mode and to provide a substantially short circuit in a non-current limited mode; charging a capacitor tank connected in series with the current limiter to provide a voltage V2 to the load, the capacitor tank being configured to charge to a voltage VICL less than VOUT while the current limiter is switched into a current limiting mode, and to charge to a voltage substantially equal to VOUT when the current limiter is switched into a non-current limiting mode; Switching the voltage down converter between an off state and an on state, switching the current limiter between a current limiting mode and a non-current limiting mode, and switching the load between an off state and an on state; The present invention relates to a method, including:

[0109] Example 15 includes the subject matter of Example 14, and optionally includes switching the voltage down converter from an off state to an on state in response to receiving a signal from a signal source external to the battery power supply.

[0110] Example 16 includes the subject matter described in Example 14, and optionally includes switching the voltage down-converter from an off state to an on state in response to the battery voltage V1 being equal to or greater than the turn-on voltage VDCin of the down-converter.

[0111] Example 17 includes the subject matter of Example 14, and optionally includes switching the current limiter from a current-limited mode to a non-current-limited mode upon detecting that VCT equals or exceeds a threshold voltage VICL less VOUT.

[0112] Example 18 includes the subject matter of any one or more of Examples 14 to 17, and optionally includes measuring battery voltage V1.

[0113] Example 19 includes the subject matter of any one or more of Examples 14 to 18, and optionally includes measuring a capacitor tank voltage VCT.

[0114] Example 20 includes the subject matter of any one or more of Examples 14 to 19, and optionally includes activating the load in response to the capacitor tank voltage VCT being charged to a voltage substantially equal to V2 or VOUT.

[0115] Example 21 includes the subject matter of any one or more of Examples 14 to 20, and optionally, the capacitor tank voltage VCT is held at a voltage substantially equal to V2 for a period of time following a period of time after the current limiter is switched to a non-current limiting mode.

[0116] Example 22 includes the subject matter of any one or more of Examples 14 to 20, and optionally, the capacitor tank voltage VCT is held at a voltage substantially equal to V2 for a period of time following the current limiter being switched to a non-current limiting mode prior to the controller activating the load.

[0117] Example 23 includes the subject matter of any one or more of Examples 14 to 22, optionally wherein the battery includes a non-flat discharge curve and a relatively high internal resistance compared to a battery including a flat discharge curve.

[0118] Example 24 includes the subject matter of 23, optionally wherein the battery comprises one or more alkaline batteries.

[0119] Example 25 includes the subject matter of any one or more of Examples 14 to 22, optionally wherein the battery comprises a flat discharge curve and a relatively low internal resistance.

[0120] Example 26 includes the subject matter of Example 25, optionally, the battery includes one or more lithium or lithium-ion batteries.

[0121] Example 27 is a device configured to operate intermittently, Battery and a battery power supply, a voltage down converter configured to be connected in series with the battery and to output a voltage VOUT that is less than the battery voltage V1; a current limiter connected in series with the voltage down converter and configured to provide a voltage drop in a current limited mode and to provide a substantially short circuit in a non-current limited mode; a capacitor tank connected in series with the current limiter to provide voltage V2 to the load, the capacitor tank being configured to charge to a voltage VICL less than VOUT while the current limiter is switched into a current-limiting mode, and to charge to a voltage substantially equal to VOUT when the current limiter is switched into a non-current-limiting mode; a controller configured to switch the voltage down converter between an off state and an on state, to switch the current limiter between a current limiting mode and a non-current limiting mode, and to switch the load between an off state and an on state; a battery power supply source; The present invention relates to a device comprising:

[0122] Example 28 includes the subject matter of Example 27, optionally, the battery includes a non-flat discharge curve and a relatively high internal resistance compared to a battery including a flat discharge curve.

[0123] Example 29 includes the subject matter of Example 27, optionally, the battery includes a flat discharge curve and a relatively low internal resistance.

[0124] Example 30 is a battery power supply for powering an intermittently operating load, comprising: a voltage converter configured to be connected in series with the battery and to output a voltage VOUT that is greater than a voltage requirement V2 of the load; a current limiter connected in series with the voltage converter and configured to be switched between a first lower current limit level and a second higher current limit level; a capacitor tank connected in series with the current limiter to provide a voltage V2 to the load, the capacitor tank being configured to charge to a voltage VICL less than VOUT while the current limiter is switched to a first, lower current limit level, and further configured to charge to a voltage VCT substantially equal to VOUT when the current limiter is switched to a second, higher current limit level; a controller configured to sense a battery voltage V1 and a capacitor tank voltage VCT, and configured to switch the current limiter from a first lower current limit level to a second higher current limit level in response to sensing that VCT>VICL; Where applicable, the subject matter described in Example 30 may optionally be combined with any one or more of Examples 1 to 29.

[0125] Example 31 relates to a battery power supply for powering an intermittently operating load, the battery power supply including: a voltage down converter configured to be connected in series with the battery and to output a voltage VOUT less than the battery voltage V1; a current limiter connected in series with the voltage down converter and configured to provide a voltage drop in a current-limited mode and to provide a substantial short circuit in a non-current-limited mode; a capacitor tank connected in series with the current limiter to provide a voltage V2 to the load, the capacitor tank being configured to be charged to a voltage VICL less than VOUT while the current limiter is switched in the current-limited mode and to be charged to a voltage substantially equal to VOUT when the current limiter is switched to the non-current-limited mode; and a controller configured to sense the battery voltage V1 and the capacitor tank voltage VCT, and to switch the voltage down converter between an off state and an on state, and to switch the current limiter between a current-limited mode and a non-current-limited mode in response to intermittent power consumption requirements of the load, and to switch the load between an off state and an on state.

[0126] Example 32 includes the subject matter of Example 31, and optionally, the controller switches the voltage down converter from an off state to an on state in response to receiving a signal from a signal source external to the battery power supply.

[0127] Example 33 includes the subject matter described in Examples 31 and / or 32, and optionally, the controller switches the voltage down converter from an on state to an off state in response to the battery voltage V1 being less than the turn-on voltage VDCin of the down converter.

[0128] Example 34 includes the subject matter of any one or more of Examples 31 to 33, and optionally, the controller switches the current limiter from a current-limiting mode to a non-current-limiting mode when it detects that VCT equals or exceeds a threshold voltage of VICL less VOUT.

[0129] Example 35 includes the subject matter of any one or more of Examples 31 to 34, optionally, wherein the controller stores the value of VCT upon detecting that VCT is less than a threshold voltage VICL.

[0130] Example 36 includes the subject matter of any one or more of Examples 31 to 35, and optionally, the controller activates the load in response to the capacitor tank voltage VCT being charged to a voltage substantially equal to VOUT.

[0131] Example 37 includes the subject matter of any one or more of Examples 31 to 36, and optionally, the capacitor tank voltage VCT is held at a voltage substantially equal to VOUT for a period of time following the current limiter being switched to a non-current limiting mode prior to the controller activating the load.

[0132] Example 38 includes the subject matter of any one or more of Examples 31-37, and optionally includes a voltage regulator for providing regulated power to the controller.

[0133] Example 39 includes the subject matter of any one or more of Examples 31 to 38, optionally wherein the battery has a non-flat discharge curve and a relatively high internal resistance compared to a battery including a flat discharge curve.

[0134] Example 40 includes the subject matter of any one or more of Examples 31 to 39, and optionally, the battery includes one or more alkaline batteries.

[0135] Example 41 includes the subject matter of any one or more of Examples 31 to 40, optionally wherein the battery includes a flat discharge curve and / or a relatively low internal resistance.

[0136] Example 42 includes the subject matter of any one or more of Examples 31 to 41, and optionally, the battery includes one or more nickel metal hydride, lithium, or lithium ion batteries.

[0137] Example 43 includes the subject matter of any one or more of Examples 31-42, optionally wherein the battery is integral with the battery power supply.

[0138] Example 44 includes the subject matter of any one or more of Examples 31 to 43, and optionally, the intermittently operating load includes an IoT device.

[0139] Example 45 includes the subject matter of any one or more of Examples 31-44, optionally wherein the controller is external to the battery power supply.

[0140] Example 46 is a method of providing DC power to an intermittently operating load from a battery, the method including applying a voltage V1 from the battery to a series-connected voltage down converter, the voltage down converter configured to output a voltage Vout that is less than V1; applying the voltage Vout to a current limiter connected in series with the voltage down converter, the current limiter configured to provide a voltage drop in a current-limited mode and to provide a substantial short circuit in a non-current-limited mode; and charging a capacitor tank connected in series with the current limiter to provide a voltage V2 to the load. wherein the capacitor tank is configured to be charged to a voltage VICL less than VOUT while the current limiter is switched to a current-limited mode, and to be charged to a voltage substantially equal to VOUT when the current limiter is switched to a non-current-limited mode; sensing a battery voltage (V1) and a voltage of the capacitor tank (VCT); switching the voltage down converter between an off state and an on state, and switching the current limiter between a current-limited mode and a non-current-limited mode in response to intermittent power consumption requirements at the load,

[0141] Example 47 includes the subject matter of Example 46, and optionally includes switching the voltage down converter from an off state to an on state in response to receiving a signal from a signal source external to the battery power supply.

[0142] Example 48 includes the subject matter described in any one or more of Examples 46 to 47, and optionally includes switching the voltage down converter from an off state to an on state in response to the battery voltage V1 being equal to or greater than the turn-on voltage VDCin of the down converter.

[0143] Example 49 includes the subject matter of any one or more of Examples 46 to 48, and optionally includes switching the current limiter from a current-limited mode to a non-current-limited mode upon detecting VCT equal to or exceeding a threshold voltage VCL less VOUT.

[0144] Example 50 includes the subject matter of any one or more of Examples 46-49, and optionally includes measuring battery voltage V1.

[0145] Example 51 includes the subject matter of any one or more of Examples 46 to 50, and optionally includes measuring the capacitor tank voltage VCT.

[0146] Example 52 includes the subject matter of any one or more of Examples 46-51, optionally including storing the value of VCT when VCT is less than threshold voltage VICL.

[0147] Example 53 includes the subject matter of any one or more of Examples 46 to 52, and optionally includes activating the load in response to the capacitor tank voltage VCT being charged to a voltage substantially equal to VOUT.

[0148] Example 54 includes the subject matter of any one or more of Examples 46 to 53, and optionally includes, following the current limiter being switched to a non-current limiting mode prior to the controller activating the load, holding the capacitor tank voltage VCT at a voltage substantially equal to Vout for a period of time.

[0149] Example 55 includes the subject matter of any one or more of Examples 46-54, optionally including adjusting the voltage of the supply to the controller.

[0150] Example 56 includes the subject matter of any one or more of Examples 46 to 55, optionally wherein the battery has a non-flat discharge curve and a relatively high internal resistance compared to a battery including a flat discharge curve.

[0151] Example 57 includes the subject matter of any one or more of Examples 46 to 56, and optionally, the battery includes one or more alkaline batteries.

[0152] Example 58 includes the subject matter of any one or more of Examples 46 to 57, optionally wherein the battery has a flat discharge curve and / or a relatively low internal resistance.

[0153] Example 59 includes the subject matter of any one or more of Examples 46 to 58, and optionally, the battery includes one or more nickel metal hydride, lithium, or lithium ion batteries.

[0154] Example 60 is a device configured to operate intermittently, comprising: a battery; a battery power supply, the battery power supply being a voltage step-down converter connected in series with the battery and configured to output a voltage VOUT less than the battery voltage V1; a current limiter connected in series with the voltage step-down converter and configured to provide a voltage drop in a current-limited mode and to provide a substantial short circuit in a non-current-limited mode; and a capacitor tank connected in series with the current limiter to provide a voltage V2 to a load, the capacitor tank being configured to be charged to a voltage VICL less than VOUT while the current limiter is switched in the current-limited mode and to be charged to a voltage substantially equal to VOUT when the current limiter is switched to the non-current-limited mode. a controller configured to switch the voltage down converter between an off state and an on state, to switch the current limiter between a current limiting mode and a non-current limiting mode in response to intermittent power consumption requirements in the load, and to switch the load between an off state and an on state; and a battery power supply including:

[0155] Example 61 includes the subject matter of Example 60, and optionally, the device includes an IoT device.

[0156] Example 62 includes the subject matter of any one or more of Examples 60 to 61, optionally wherein the battery has a non-flat discharge curve and a relatively high internal resistance compared to a battery including a flat discharge curve.

[0157] Example 63 includes the subject matter of any one or more of Examples 60 to 62, and optionally, the battery includes one or more alkaline batteries.

[0158] Example 64 includes the subject matter of any one or more of Examples 60 through 63, optionally, the battery having a flat discharge curve and / or a relatively low internal resistance.

[0159] Example 65 includes the subject matter of any one or more of Examples 60 to 64, and optionally, the battery includes one or more nickel metal hydride, lithium, or lithium ion batteries.

[0160] The various features and steps described above, and other known equivalents for each such feature or step, can be mixed and matched by those skilled in the art to implement a method in accordance with the principles described herein. While the present disclosure has been provided in the context of certain embodiments and examples, it will be understood by those skilled in the art that the present disclosure extends beyond the embodiments specifically described to other alternative embodiments and / or uses, and obvious modifications and equivalents thereof. Accordingly, the present disclosure is not limited by the specific disclosure of the embodiments herein.

[0161] Any digital computer system, module, and / or engine illustrated herein may be configured or, as the case may be, programmed to implement the methods disclosed herein, and so long as the system, module, and / or engine is configured to implement such methods, it falls within the scope and spirit of the present disclosure. When the system, module, and / or engine is programmed to perform specific functions in accordance with computer-readable and executable instructions from program software that implement the methods disclosed herein, it effectively becomes a special-purpose computer specific to the implementation of the methods disclosed herein. The methods and / or processes disclosed herein may be implemented as a computer program product that may be tangibly embodied in an information carrier, including, for example, in a non-transitory tangible computer-readable and / or non-transitory tangible machine-readable storage device. The computer program product may be directly loadable into the internal memory of a digital computer, comprising software code portions for implementing the methods and / or processes disclosed herein. The term "non-transitory" is used to exclude transient, propagating signals, but to include any volatile or non-volatile computer memory technology suitable for the application, as the case may be. Additionally or alternatively, the methods and / or processes disclosed herein may be implemented as a computer program product that may be intangibly embodied by a computer-readable signal medium. A computer-readable signal medium may include a propagated data signal having computer-readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electromagnetic, optical, or any suitable combination thereof. A computer-readable signal medium may be any computer-readable medium that is not a non-transitory computer or machine-readable storage device, but is capable of communicating, propagating, or transporting a program for use by or in connection with the apparatus, system, platform, methods, operations, and / or processes described herein.

[0162] The terms "non-transitory computer-readable storage device" and "non-transitory machine-readable storage device" encompass distribution media, intermediate storage media, computer executable memory, and any other medium or device capable of storing for subsequent reading by a computer program that implements embodiments of the methods disclosed herein. A computer program product may be deployed to be executed on one computer or on multiple computers at one site or distributed across multiple sites and interconnected by one or more communication networks.

[0163] These computer-readable and executable instructions may be provided to a processor of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions executing on the processor of the computer or other programmable data processing apparatus create means for implementing the functions / acts specified in one or more blocks of the flowcharts and / or block diagrams. These computer-readable and executable program instructions may also be stored on a computer-readable storage medium that can instruct a computer, programmable data processing apparatus, and / or other device to function in a particular manner, such that a computer-readable storage medium having instructions stored thereon comprises an article of manufacture containing instructions that implement aspects of the functions / acts specified in one or more blocks of the flowcharts and / or block diagrams.

[0164] The computer-readable and executable instructions may also be loaded into a computer, other programmable apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable data processing apparatus, or other device to create a computer-implemented process, such that the instructions executing on the computer, other programmable apparatus, or other device implement the functions / acts specified in one or more blocks of the flowcharts and / or block diagrams.

[0165] In this description, unless expressly stated otherwise, adjectives such as "substantially" and "about" modifying a condition or relationship characteristic of one or more features of an embodiment of the invention should be understood to mean that the condition or characteristic is defined within an acceptable tolerance for operation of the embodiment for its intended application.

[0166] Unless otherwise specified, the terms "about" and / or "close" in relation to a magnitude or value may imply a range inclusive of the endpoints of -10% to +10% of the respective magnitude or value.

[0167] It should be noted that when an embodiment refers to the condition "above a threshold," this should not be interpreted as excluding an embodiment that refers to the condition "equal to or above a threshold." Similarly, when an embodiment refers to the condition "below a threshold," this should not be interpreted as excluding an embodiment that refers to the condition "equal to or below a threshold." It is clear that when a condition is interpreted as being met if the value of a given parameter is above a threshold, the same condition is not considered to be met if the value of the given parameter is equal to or below the given threshold. Conversely, when a condition is interpreted as being met if the value of a given parameter is equal to or above a threshold, the same condition is not considered to be met if (and only if) the value of the given parameter is below the given threshold.

[0168] When a claim or the specification refers to "a" or "an" element or feature, it should be understood that such a reference is not to be construed as meaning that there is only one of that element. Thus, for example, a reference to "an element" or "at least one element" can also encompass "one or more elements."

[0169] As used herein, the terms "configuring" and / or "adapting" for a purpose, or variations thereof, connote the use of materials and / or components designed for that purpose and / or implemented to achieve that purpose and / or in a manner operable or operative to achieve that purpose.

[0170] Unless otherwise specified or applicable, the use of the wording "and / or" between the last two members of a list of options for selection indicates that one or more selections of the listed options are appropriate and may be made, and may be used interchangeably with the words "at least one of," "any one of," or "one or more of," followed by a listing of various options.

[0171] As used herein, the phrase "A, B, C, or any combination of the foregoing" should be interpreted to mean all of: (i) A or B or C, or any combination of A, B, and C; (ii) at least one of A, B, and C; and (iii) A, and / or B, and / or C. This concept is illustrated for three elements (i.e., A, B, C), but is extended to fewer and greater numbers of elements (e.g., A, B, C, D, etc.).

[0172] It should be noted that the terms "operable to" or "operating to" can encompass the meaning of the term "adapted or configured to." In other words, a machine "operable to" or "acts to" perform a task can, in some embodiments, encompass the mere ability to perform (e.g., "adapted to") a function, and, in some other embodiments, encompass a machine that is actually made (e.g., "configured") to perform that function.

[0173] Throughout this application, various embodiments of the present invention may be presented in a range format. It should be understood that the description in range format is for convenience and brevity only and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all possible subranges as well as individual numerical values ​​within that range. For example, description of a range such as 1 to 6 should be considered to have specifically disclosed subranges such as 1 to 4, 1 to 4, 1 to 5, 2 to 4, 2 to 6, 4 to 6, etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the broadness of the range.

[0174] Whenever a range of numerical values ​​is given herein, it is intended to include any recited number (fractional or integer) within the range given. The phrases "ranging between" a first recited number and a second recited number and "ranging from" a first recited number to a second recited number are used interchangeably herein and are intended to include the first recited number, the second recited number, and all fractional and integer numbers therebetween.

[0175] It will be appreciated that combinations of features disclosed in different embodiments are also within the scope of the present invention.

[0176] While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.

Claims

1. 1. A battery power supply for powering an intermittently operating load, comprising: a voltage down converter configured to be connected in series with the battery and to output a voltage VOUT that is less than the battery voltage V1; a current limiter connected in series with the voltage down converter and configured to provide a voltage drop in a current limited mode and to provide a substantially short circuit in a non-current limited mode; a capacitor tank connected in series with the current limiter to provide a voltage V2 to the load, the capacitor tank being configured to be charged to a voltage V less than V while the current limiter is switched to the current limiting mode, and to be charged to a voltage substantially equal to V when the current limiter is switched to the non-current limiting mode; a controller configured to sense the battery voltage (V1) and the capacitor tank voltage (VCT), and configured to switch the voltage down converter between an off state and an on state, switch the current limiter between the current limiting mode and the non-current limiting mode, and switch the load between an off state and an on state; a battery power supply comprising:

2. 2. The battery power supply of claim 1, wherein the controller switches the voltage down converter from the off state to the on state in response to receiving a signal from a signal source external to the battery power supply.

3. 2. The battery power supply of claim 1, wherein the controller switches the voltage down converter from the off state to the on state in response to the battery voltage V1 being equal to or greater than a turn-on voltage VDCin of the down converter.

4. 2. The battery power supply of claim 1, wherein the controller switches the current limiter from the current limited mode to the non-current limited mode when the controller detects that VCT equals or exceeds a threshold voltage of VICL less VOUT.

5. 5. A battery power supply according to claim 1, wherein the controller activates the load in response to the capacitor tank being charged to a voltage substantially equal to VOUT.

6. 6. The battery power supply of claim 5, wherein the voltage VCT of the capacitor tank is held at a voltage substantially equal to V2 for a period of time following the current limiter being switched to the non-current limiting mode prior to the controller activating the load.

7. 7. A battery power supply according to any one or more of the preceding claims, further comprising a voltage regulator for providing regulated power to the controller.

8. 8. A battery power supply according to any one or more of the preceding claims, wherein the battery comprises a non-flat discharge curve and a relatively high internal resistance compared to batteries comprising a flat discharge curve.

9. 9. The battery power supply of claim 1, wherein the batteries comprise one or more alkaline batteries, one or more non-lithium batteries, one or more lithium batteries, or one or more lithium-ion batteries.

10. 8. A battery power supply according to any one or more of the preceding claims, wherein the battery comprises a flat discharge curve and a relatively low internal resistance.

11. 11. A battery power supply according to any one or more of the preceding claims, wherein the battery is integral with the battery power supply.

12. 12. A battery power supply according to any one or more of the preceding claims, wherein the intermittently operating load comprises an Internet of Things (IoT) device.

13. 13. A battery power supply according to any one or more of the preceding claims, wherein the controller is external to the battery power supply.

14. 1. A method for providing DC power to an intermittently operating load from a battery, the method comprising: applying a voltage V1 from the battery to a series-connected voltage down converter, the voltage down converter configured to output a voltage VOUT that is less than V1; applying the voltage VOUT to a current limiter connected in series with the voltage down converter, the current limiter configured to provide a voltage drop in a current limited mode and to provide a substantially short circuit in a non-current limited mode; charging a capacitor tank connected in series with the current limiter to provide a voltage V2 to the load, the capacitor tank being configured to charge to a voltage VICL less than VOUT while the current limiter is switched to the current limiting mode, and to charge to a voltage substantially equal to VOUT when the current limiter is switched to the non-current limiting mode; switching the voltage down converter between an off state and an on state, switching the current limiter between the current limiting mode and the non-current limiting mode, and switching the load between an off state and an on state; A method comprising:

15. 15. The battery power supply of claim 14, including switching the voltage down converter from the off state to the on state in response to receiving a signal from a signal source external to the battery power supply.

16. 15. The method of claim 14, comprising switching the voltage down-converter from the off state to the on state in response to the battery voltage V1 being equal to or greater than a turn-on voltage VDCin of the down-converter.

17. 15. The method of claim 14, comprising switching the current limiter from the current limiting mode to the non-current limiting mode upon detecting that VCT equals or exceeds a threshold voltage VICL less VOUT.

18. 18. The method of any one or more of claims 14 to 17, comprising measuring the battery voltage V1.

19. 19. A method according to any one or more of claims 14 to 18, comprising measuring a capacitor tank voltage VCT.

20. 20. The method of claim 14, further comprising activating the load in response to the voltage VCT of a capacitor tank being charged to a voltage substantially equal to Vout.

21. 21. The method of claim 14, wherein the voltage VCT across the capacitor tank is held at a voltage substantially equal to V2 for a period of time following a period of time after the current limiter is switched to the non-current limiting mode.

22. 21. The method of claim 14, wherein the voltage VCT of the capacitor tank is held at a voltage substantially equal to V2 for a period of time following the current limiter being switched to the non-current limiting mode and before the controller activates the load.

23. 23. The method of any one or more of claims 14 to 22, wherein the battery comprises a non-flat discharge curve and a relatively high internal resistance compared to batteries comprising a flat discharge curve.

24. 24. The method of claim 23, wherein the battery comprises one or more alkaline batteries.

25. 23. The method of any one or more of claims 14 to 22, wherein the battery comprises a flat discharge curve and a relatively low internal resistance.

26. 26. The method of claim 25, wherein the battery comprises one or more lithium or lithium-ion batteries.

27. 1. A device configured to operate intermittently, comprising: Battery and a battery power supply, a voltage down converter configured to be connected in series with the battery and to output a voltage VOUT that is less than a battery voltage V1; a current limiter connected in series with the voltage down converter and configured to provide a voltage drop in a current limited mode and to provide a substantially short circuit in a non-current limited mode; a capacitor tank connected in series with the current limiter to provide a voltage V2 to a load, the capacitor tank being configured to be charged to a voltage V less than V while the current limiter is switched to the current limiting mode, and to be charged to a voltage substantially equal to V when the current limiter is switched to the non-current limiting mode; a controller configured to switch the voltage down converter between an off state and an on state, to switch the current limiter between the current limiting mode and the non-current limiting mode, and to switch the load between an off state and an on state; a battery power supply source; A device comprising:

28. 28. The device of claim 27, wherein the battery comprises a non-flat discharge curve and a relatively high internal resistance compared to batteries comprising flat discharge curves.

29. 28. The device of claim 27, wherein the battery comprises a flat discharge curve and a relatively low internal resistance.

30. 1. A battery power supply for powering an intermittently operating load, comprising: a voltage converter configured to be connected in series with a battery and to output a voltage VOUT that is greater than a voltage requirement V2 of the load; a current limiter connected in series with the voltage converter and configured to be switched between a first lower current limit level and a second higher current limit level; a capacitor tank connected in series with the current limiter to provide the voltage V2 to the load, the capacitor tank being configured to be charged to a voltage VICL less than VOUT while the current limiter is switched to the first lower current limit level, and further configured to be charged to a voltage VCT substantially equal to VOUT when the current limiter is switched to the second higher current limit level; a controller configured to sense a battery voltage V1 and the voltage VCT of the capacitor tank, and configured to switch the current limiter from the first lower current limit level to the second higher current limit level in response to sensing that VCT>VICL; a battery power supply comprising:

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