Multi-battery management for a portable device

Abstract

A method includes determining a first voltage level of a first battery and a second voltage level of a second battery. Based on the condition that the difference between the first voltage level and the second voltage level satisfies a first threshold and the magnitude of the current does not satisfy a second threshold, one of the first battery or the second battery is disconnected from one or more components, and the other of the first battery or the second battery is used to power one or more components of a portable device. The first battery and the second battery are used to power one or more components of the portable device based on one or more of the following conditions: the difference between the first voltage level and the second voltage level does not satisfy the first threshold, or the magnitude of the current satisfies the second threshold.

Description

Technical Field

[0001] This invention relates generally to batteries, and more specifically to battery management for portable devices. Prior Technology

[0002] The use of batteries in various forms has become virtually ubiquitous in today's world. With the increasing prevalence of portable or cordless devices (such as power tools (e.g., drills, saws, lawnmowers, blowers, grinders, etc.), small appliances (e.g., mixers, blenders, coffee grinders, etc.), communication devices (e.g., smartphones, personal digital assistants, etc.), and office equipment (e.g., computers, tablets, printers, etc.), the use of chemical processes and different battery technologies is common.

[0003] Cordless devices can be powered by a single battery or multiple batteries. For some applications, using multiple batteries can provide better performance compared to using a single battery, such as by enabling a wider range of current to be supplied to the components of the portable device. Furthermore, using multiple batteries can improve the reliability of the portable device.

[0004] In some cases, incorporating multiple batteries into a portable device can be expensive. For example, a "matching" process may be performed during device manufacturing or assembly to ensure that the batteries have similar characteristics, such as charge capacity, charge rate, discharge rate, impedance, or other properties. In some cases, one or more batteries may be unused, replaced, and / or discarded due to "mismatch" with other batteries. As a result, product yield may decrease, thereby increasing the costs associated with the portable device. Furthermore, if one or more characteristics of the batteries in a portable device are mismatched, performance may degrade. Summary of the Invention

[0005] According to one aspect of this disclosure, a portable device includes a multi-battery management device configured to perform battery management operations, such as a battery "balancing" process. The multi-battery management device can selectively connect or disconnect the batteries of the portable device from one or more components of the portable device, such as the electric motor of the portable device. The multi-battery management device can be configured to perform the connection or disconnection based on the voltage level difference of the batteries, or based on the magnitude of the current supplied to the one or more components, or both.

[0006] For illustration, in one example, the multi-battery management device can compare the difference in voltage levels of the batteries with a first threshold. In response to the difference satisfying (e.g., greater than, or greater than or equal to) the first threshold, the multi-battery management device can disconnect one of the batteries from the one or more components. The multi-battery management device can be configured to selectively disconnect a battery with a lower voltage level (e.g., to prevent other batteries from charging that battery) and can use a battery with a higher voltage level to power the one or more components. Alternatively, if the difference in battery voltage levels does not satisfy the first threshold, all of the batteries are connected to the one or more components.

[0007] In the illustrative example, the multi-battery management device is configured to determine the magnitude of the current supplied to the one or more components. In response to the current magnitude satisfying a second threshold, the multi-battery management device can couple each battery to the one or more components (e.g., regardless of the voltage level of those batteries). Therefore, (e.g., during high-power activities, such as when a motor is generating a large amount of horsepower or torque) the power supplied to the one or more components can be increased.

[0008] Using a multi-battery management device to selectively connect and disconnect batteries can improve the performance, reliability, or lifespan of a portable device. For example, by selectively disconnecting a battery, repeated charging and discharging of that battery by other batteries can be reduced or avoided. Therefore, for some battery technologies, this can extend battery life.

[0009] Furthermore, in some cases, using a multi-battery management device can enable a more "relaxed" matching process during device manufacturing or assembly. For example, by selectively connecting or disconnecting batteries to compensate for differences between them (e.g., charge capacity, charge rate, discharge rate, or impedance), the tolerances used for matching batteries can be relaxed, thereby improving product yield. Alternatively or additionally, one or more testing operations in the matching process can be omitted, such as by omitting tests on charge capacity, charge rate, discharge rate, impedance, one or more other characteristics, or combinations thereof.

[0010] Furthermore, using switchable batteries connected in parallel according to some aspects of this disclosure can avoid certain drawbacks associated with batteries connected in series. For example, some conventional portable devices avoid battery-to-battery charging by implementing a power supply comprising multiple batteries connected in series. As a result, the output power increases (due to the increased voltage of the power supply), which may require redesigning one or more device components to accommodate the increased voltage (e.g., by implementing a higher-power motor and control circuitry compatible with the increased voltage). By using switchable batteries connected in parallel according to some aspects of this disclosure, the output power can be increased without redesigning to implement higher-power components (thus reducing device cost), while reducing or avoiding battery-to-battery charging as in some conventional multi-battery designs.

[0011] Furthermore, using multiple switchable batteries according to some aspects of this disclosure can increase the amount of power available to one or more device components (e.g., an electric motor), while also providing certain advantages associated with single-battery implementations. For example, in some portable devices, a battery with a low voltage state may cause a power outage or shutdown event. In portable devices according to some aspects of this disclosure, a first battery with a low voltage can be disconnected from one or more components before a low voltage causes the portable device to enter a power-off state. The portable device can then continue operating using a second battery with a voltage greater than that of the first battery. In this state, the portable device operates in a low-power or reduced-power mode, which may be preferable in some cases to entering a shutdown state as in some conventional portable devices.

[0012] The features and technical advantages of the invention have been summarized quite extensively above in order to better understand the detailed description of the invention below. Additional features and advantages of the invention that form the subject matter of the claims will be described below. Those skilled in the art will understand that the disclosed concepts and specific embodiments can be readily used as the basis for modifications or the design of other structures for achieving the same purpose of the invention. Those skilled in the art will also recognize that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features (both in relation to their organization and operation) and other objects and advantages considered characteristic of the invention will be better understood from the following description when considered in conjunction with the accompanying drawings. However, it should be clearly understood that each figure is provided for illustrative and descriptive purposes only and is not intended to be a limitation of the invention. Simple Explanation of the Diagram

[0013] To gain a more complete understanding of the invention, reference is now made to the following description taken in conjunction with the accompanying drawings, in which:

[0014] [Figure 1] illustrates an example of a portable device including a battery management device according to some aspects of this disclosure;

[0015] [Figure 2] is a flowchart illustrating an example of the operation method of a portable device (as shown in Figure 1) according to certain aspects of this disclosure;

[0016] [Figure 3] shows an example of the electric lawnmower configuration of the portable device of Figure 1 according to some aspects of this disclosure;

[0017] [Figure 4] shows an example of the electric blower configuration of the portable device of Figure 1 according to some aspects of this disclosure;

[0018] [Figure 5] illustrates an example of a circuit that may be included in a portable device (as shown in Figure 1) according to some aspects of this disclosure;

[0019] [Figures 6A, 6B, 6C, 6D, 6E, 6F, 6G, 6H, and 6I] illustrate additional examples of circuitry that may be included in a portable device (as shown in Figure 1) according to some aspects of this disclosure; and

[0020] [Figures 7A and 7B] illustrate examples of devices that may be included in a portable device (as shown in Figure 1) according to some aspects of this disclosure. Implementation

[0021] Referring to Figure 1, a specific illustrative example of a portable device is depicted, and it is generally designated as 100. As an illustrative example, portable device 100 may correspond to a cordless power tool, such as an electric lawnmower, electric blower, or other power tool. In another example, portable device 100 may correspond to other devices, such as cordless household appliances. In an additional example, portable device 100 may correspond to a personal electronic device such as a telephone or computer.

[0022] The portable device 100 includes one or more components 102 and a multi-battery power source 130. The one or more components 102 are configured to receive power from the multi-battery power source 130. In some examples, the one or more components 102 include an electric motor 104 of the portable device 100.

[0023] The multi-battery power supply 130 includes multiple batteries. In the example of Figure 1, the multi-battery power supply 130 includes a first battery 132 and a second battery 134. In some examples, the second battery 134 is coupled in parallel with the first battery 132 or configured to discharge in parallel with the first battery 132. Although two batteries 130 and 132 are shown in the example of Figure 1, in other examples, the multi-battery power supply 130 may include a different number of batteries, such as three, four, or five batteries. The multi-battery power supply 130 is configured to provide current C1 to one or more components 102.

[0024] The current C1 is generated at least in part using the first battery 132 and the second battery 134. In one example, the first current provided by the first battery 132 is added to the second current provided by the second battery 134 to generate the current C1.

[0025] In some examples, the multi-battery power supply 130 includes one or more battery packs. The battery packs may include one or more batteries integrated within a battery casing (such as a protective battery housing). As an illustrative example, the battery casing may include a plastic material or encapsulating material molded around the one or more batteries. To further illustrate, in one example, a first battery 132 includes a first battery pack, and a second battery 134 includes a second battery pack different from the first battery pack. In other examples, the first battery 132 and the second battery 134 are integrated within a common battery pack (or other device). In some examples, the first battery 132 and the second battery 134 include lithium-ion (Li-ion) batteries or one or more Li-ion battery packs. In other embodiments, one or more other battery types may be used.

[0026] The portable device 100 further includes a multi-battery management device 110. The multi-battery management device 110 is coupled to a multi-battery power supply 130. In the example of FIG1, the multi-battery management device 110 includes a sensor interface 112, a comparator circuit 114, and a control circuit 122.

[0027] The control circuit 122 may include multiple switching devices, such as a first switching device 124 and a second switching device 126. Each switching device 124, 126 may include one or more transistors. In one example, each switching device 124, 126 includes multiple field-effect transistors (FETs). The first switching device 124 is coupled to a first battery 132, and the second switching device 126 is coupled to a second battery 134. The first battery 132 is coupled to one or more components 102 via the first switching device 124, and the second battery 134 is coupled to one or more components 102 via the second switching device 126.

[0028] The portable device 100 may further include one or more battery sensors 136. The one or more battery sensors 136 may be coupled to a multi-battery power source 130 (e.g., coupled to a first battery 132 and a second battery 134). The one or more battery sensors 136 may be further coupled to a multi-battery management device 110 (e.g., coupled to a sensor interface 112).

[0029] The portable device 100 may further include a power-on switch 106. The power-on switch 106 may be coupled to one or more components 102 and to a multi-battery management device 110 (e.g., coupled to a sensor interface 112).

[0030] During operation, the multi-battery power supply 130 can supply power to one or more components 102. For illustration, in one example, the portable device corresponds to an electric lawnmower, and the multi-battery power supply 130 is configured to supply power to the electric motor 104 to operate the lawnmower's blades. In another example, the portable device corresponds to an electric blower, and the multi-battery power supply 130 is configured to supply power to the electric motor 104 to operate the electric blower's fan.

[0031] The batteries of the multi-battery power supply 130 can be charged by a power source. In some examples, the portable device 100 is configured to charge the batteries of the multi-battery power supply 130 by a mains power supply. For example, the portable device 100 may include a power supply port configured to be coupled to a mains power outlet via a power supply device. Alternatively or additionally, the batteries of the multi-battery power supply 130 can be charged by another energy recovery mechanism. For illustration, the batteries of the multi-battery power supply 130 can be charged by a regenerative energy recovery mechanism that slows down a component (e.g., rotor or other moving part) of an electric motor 104 by converting the kinetic energy of that component into voltage, which is supplied to the multi-battery power supply 130 to charge one or both of the first battery 132 and the second battery 134.

[0032] In some cases, the batteries of the multi-battery power supply 130 may discharge at different rates, or charge at different rates, or discharge and charge at different rates. For example, differences in trace impedance associated with the first battery 132 and the second battery 134 (or other components connected to the first battery 132 and the second battery 134) may cause the first battery 132 and the second battery 134 to discharge, charge, or discharge and charge unequally. As another example, temperature differences between the first battery 132 and the second battery 134 (or other components) may cause the first battery 132 and the second battery 134 to discharge, charge, or discharge and charge unequally. Furthermore, in some cases, the charging capacity or other characteristics of the first battery 132 may differ from those of the second battery 134. Therefore, in some cases, the first voltage level V1 of the first battery 132 may differ from the second voltage level V2 of the second battery 134.

[0033] According to one aspect of this disclosure, the multi-battery management device 110 is configured to designate at least one battery of the multi-battery power supply 130 as a primary battery based on the voltage level of the batteries of the multi-battery power supply 130, and disconnect one or more other batteries of the multi-battery power supply 130 from one or more components 102. By disconnecting one or more batteries from one or more components 102, the multi-battery management device 110 can reduce or avoid energy exchange between batteries (e.g., one battery providing energy to another battery instead of providing energy to one or more components 102). Therefore, compared to a system where at least some power is transferred from one battery to another during discharge (instead of to one or more components 102), the power supplied to one or more components 102 can be increased, thereby improving the performance and user experience associated with the portable device 100.

[0034] To enable battery management operations, the multi-battery management device 110 is configured to receive one or more signals indicating the operating characteristics of the first battery 132 and the second battery 134. For illustration, these one or more signals may include a first indication 138 of a first voltage level V1 of the first battery 132, a second indication 140 of a second voltage level V2 of the second battery 134, and a third indication 142 of the magnitude of the current C1. In one example, a sensor interface 112 is configured to initiate sensor operations performed by one or more battery sensors 136 to generate the first indication 138 of the first voltage level V1 of the first battery 132, the second indication 140 of the second voltage level V2 of the second battery 134, and the third indication 142 of the magnitude of the current C1. The sensor interface 112 may be configured to receive the first indication 138 of the first voltage level V1, the second indication 140 of the second voltage level V2, and the third indication of the magnitude of the current C1 from one or more battery sensors 136.

[0035] In some implementations, the sensor interface 112 is configured to perform one or more operations based on a first indication 138, a second indication 140, and a third indication 142. For example, depending on a particular implementation, the sensor interface 112 may be configured to perform a digital-to-analog (DAC) conversion operation or an analog-to-digital (ADC) conversion operation based on the first indication 138, the second indication 140, and the third indication 142. In another example, the sensor interface 112 may include one or more drivers configured to convert the first indication 138, the second indication 140, and the third indication 142 from a first supply voltage associated with a first voltage domain of one or more battery sensors 136 to a second supply voltage associated with a second voltage domain of the multi-battery management device 110. Alternatively or additionally, the sensor interface 112 may be configured to perform impedance adjustment to match the input impedance of the multi-battery management device 110 with the output impedance of one or more battery sensors 136.

[0036] Comparison circuit 114 is configured to receive a first indication 138, a second indication 140, and a third indication 142 (or signals corresponding to the first indication 138, the second indication 140, and the third indication 142) from sensor interface 112. Comparison circuit 114 is configured to determine the difference between a first voltage level V1 and a second voltage level V2. For example, comparison circuit 114 may be configured to determine the difference by subtracting the first voltage level V1 from the second voltage level V2 (or vice versa).

[0037] Comparison circuit 114 is configured to compare the difference with a first threshold 116. Comparison circuit 114 may be configured to generate a first output indicating whether the difference satisfies (e.g., greater than, or greater than or equal to) the first threshold 116.

[0038] Control circuit 122 is configured to disconnect either the first battery 132 or the second battery 134 from one or more components 102, at least in part, based on a first threshold 116 satisfied by the difference between the first voltage level V1 and the second voltage level V2. For example, if the difference indicates that the first voltage level V1 is significantly greater than the second voltage level V2, the second switching device 126 can be deactivated to decouple the second battery 134 from one or more components 102 (and reduce or avoid charging of the second battery 134 by the first battery 132). As another example, if the difference indicates that the second voltage level V2 is significantly greater than the first voltage level V1, the first switching device 124 can be deactivated to decouple the first battery 132 from one or more components 102 (and reduce or avoid charging of the first battery 132 by the second battery 134).

[0039] In one example, comparator circuit 114 is configured to provide one or more control signals to control circuit 122 to selectively activate (or deactivate) switching devices 124, 126. For example, comparator circuit 114 may be configured to provide control signal 120 (e.g., a multi-bit control signal) to the first switching device 124 or the second switching device 126. In one example, control signal 120 has a specific value that activates (or deactivates) the first switching device 124 or the second switching device 126. As an illustrative example, a first value (e.g., a logic 0 value) of control signal 120 may activate the first switching device 124 to couple the first battery 132 to one or more components 102, while a second value (e.g., a logic 1 value) may deactivate the first switching device 124 to disconnect the first battery 132 from one or more components 102. Further, a similar control mechanism may be provided for the second battery 134 (e.g., by providing a second control signal to the second switching device 126 in a manner similar to providing control signal 120 to the first switching device 124).

[0040] The multi-battery management device 110 is configured to select whether to disconnect the first battery 132 or the second battery 134 based on a comparison of voltage levels V1 and V2. For example, the multi-battery management device 110 may select to disconnect the first battery 132 based on the first voltage level V1 being less than the second voltage level V2. In another example, the multi-battery management device 110 may select to disconnect the second battery 134 based on the second voltage level V2 being less than the first voltage level V1.

[0041] In some implementations, battery management operations are further performed based on the magnitude of the current C1. For example, if the magnitude of the current C1 is relatively large, both batteries 132 and 134 can be connected to one or more components 102 (e.g., regardless of whether the difference between the first voltage level V1 and the second voltage level V2 satisfies the first threshold 116). In this case, both batteries 132 and 134 can be used to enable the high-power operation mode of the portable device 100. In another example, if the magnitude of the current C1 is relatively small, one or both of batteries 132 and 134 can be selectively connected to one or more components 102 (e.g., based on whether the difference between the first voltage level V1 and the second voltage level V2 satisfies the first threshold 116).

[0042] To further illustrate, the comparator circuit 114 can be configured to compare the magnitude of the current C1 with a second threshold 118. The comparator circuit 114 can be configured to generate a second output indicating whether the magnitude of the current C1 satisfies (e.g., is greater than, or greater than or equal to) the second threshold 118. The comparator circuit 114 can be configured to set the value of the control signal 120 based on whether the difference between the first voltage level V1 and the second voltage level V2 satisfies a first threshold 116, or based on whether the magnitude of the current C1 satisfies the second threshold 118, or based on both.

[0043] For example, if the difference between the first voltage level V1 and the second voltage level V2 does not meet the first threshold 116, or if the magnitude of the current C1 meets the second threshold 118, or if both of these conditions are met, then the control signal 120 may have a first value (e.g., a logic 0 value). In this example, batteries 132 and 134 may both supply power to one or more components 102.

[0044] If the difference between the first voltage level V1 and the second voltage level V2 satisfies a first threshold 116, and if the magnitude of the current C1 does not satisfy a second threshold 118, then the control signal 120 may have a second value (e.g., a logic 1). In this case, the battery with the lower voltage level can be disconnected from one or more components 102 by means of the control signal 120. For example, if the difference between the first voltage level V1 and the second voltage level V2 satisfies the first threshold 116, if the magnitude of the current C1 does not satisfy the second threshold 118, and if the first voltage level V1 is less than the second voltage level V2, then the second value of the control signal 120 can be provided to the first switching device 124 to disconnect the first battery 132 from one or more components 102. In another example, if the difference between the first voltage level V1 and the second voltage level V2 satisfies the first threshold 116, if the magnitude of the current C1 does not satisfy the second threshold 118, and if the second voltage level V2 is less than the first voltage level V1, then the second value of the control signal 120 can be provided to the second switching device 126 to disconnect the second battery 134 from one or more components 102.

[0045] After one of the first battery 132 or the second battery 134 is disconnected from one or more components 102, power can be supplied to one or more components 102 from the other of the first battery 132 or the second battery 134. Alternatively, when both the first battery 132 and the second battery 134 are coupled to one or more components 102, power can be supplied to one or more components 102 from both the first battery 132 and the second battery 134.

[0046] In some implementations, the multi-battery management device 110 is configured to detect a battery management trigger event and initiate battery management operation based on the battery management trigger event. In some examples, detecting a battery management trigger event includes (e.g., in response to user input received via power-on switch 106) detecting a power-on event at the portable device 100, such as detecting a power-on signal generated by power-on switch 106 in response to user input received via power-on switch 106. The power-on switch may be provided to the electric motor 104 to initiate operation of the electric motor 104. For example, in response to the power-on event, the multi-battery power supply 130 may provide current C1 to one or more components 102.

[0047] In response to the detection of the battery management trigger event, the multi-battery management device 110 can determine a first voltage level V1 of the first battery 132 and a second voltage level V2 of the second battery 134. In one example, the sensor interface 112 is configured to initiate sensor operations performed by one or more battery sensors 136 in response to the battery management trigger event. For example, in response to receiving a power-on signal from the power-on switch 106, the sensor interface 112 can provide an enable signal to one or more battery sensors 136 to initiate the sensor operation.

[0048] Alternatively or additionally, battery management trigger events may include or correspond to one or more other events. For example, battery management operations may be performed periodically or pseudo-periodically at portable device 100. For illustration, portable device 100 may include a counter configured to store a value indicating the amount of time (e.g., the number of clock cycles) since the last battery management operation. In response to detecting that the value meets a threshold, multiple battery management devices 110 may trigger a battery management operation (e.g., by triggering one or more battery sensors 136 to measure or remeasure the magnitudes of a first voltage level V1, a second voltage level V2, and current C1), and may reset the value of the counter.

[0049] Alternatively or additionally, battery management operation may be performed in response to detecting that the portable device 100 is connected to a power source, or in response to detecting that the portable device 100 is disconnected from a power source, or in response to both. For illustration, battery management operation may be performed in response to detecting that the portable device 100 is connected to a mains power outlet, or in response to detecting that the portable device 100 is disconnected from a mains power outlet, or in response to both.

[0050] In some examples, after switching to a single-cell operating mode or a multi-cell operating mode, the multi-cell management device 110 is configured to monitor indications of voltage levels V1, V2, and current C1 to determine whether to revert to the multi-cell or single-cell mode. For example, the multi-cell management device 110 may be configured to revert from the single-cell mode to the multi-cell mode in response to detecting that the difference between voltage levels V1 and V2 no longer meets a first threshold 116 (or a third threshold) or that the magnitude of current C1 meets a second threshold 118 (or a fourth threshold).

[0051] One or more aspects described with reference to Figure 1 can improve the performance of the portable device 100. For example, selectively connecting and disconnecting batteries 132, 134 using a multi-battery management device 110 can improve the performance, reliability, or lifespan of the multi-battery power supply 130. As a specific example, by selectively disconnecting the batteries of the multi-battery power supply 130, repeated charging and discharging of that battery by another battery in the multi-battery power supply 130 can be reduced or avoided. Therefore, for certain battery technologies, battery life can be extended.

[0052] Furthermore, in some cases, the use of a multi-battery management device 110 can enable a more "relaxed" matching process during the manufacture or assembly of the portable device 100. For example, by selectively connecting or disconnecting batteries 132 and 134 to compensate for differences between them (e.g., charging capacity, charge rate, discharge rate, or impedance), the tolerances for matching the batteries can be relaxed. Alternatively or additionally, one or more test operations in the matching process can be omitted, such as by omitting tests on the charging capacity, charge rate, discharge rate, impedance, one or more other characteristics, or combinations thereof, of batteries 132 and 134.

[0053] While some examples are described in the references to connecting a single battery of the multi-battery power supply 130 to one or more components 102 and disconnecting a single battery of the multi-battery power supply 130 from one or more components 102, it is worth noting that other examples are also within the scope of this disclosure. For example, multiple batteries of the multi-battery power supply 130 may be connected to one or more components 102, while another battery of the multi-battery power supply 130 may be disconnected from one or more components 102. Alternatively or additionally, one battery of the multi-battery power supply 130 may be connected to one or more components 102, while multiple other batteries of the multi-battery power supply 130 may be disconnected from one or more components 102. Alternatively or additionally, multiple batteries of the multi-battery power supply 130 may be connected to one or more components 102, while multiple other batteries of the multi-battery power supply 130 may be disconnected from one or more components 102.

[0054] It is worth noting that the features described with reference to the multi-battery management device 110 can be implemented using various components or techniques, such as digital circuits, analog circuits, mixed-signal circuits, or combinations thereof. For illustration, in some examples, the comparator circuit 114 includes analog hardware, such as one or more operational amplifiers configured to perform a comparison of signals and generate an output indicating the comparison result. Alternatively or additionally, the multi-battery management device 110 may include memory and a processor configured to retrieve instructions from the memory. The processor can execute these instructions to perform the operations described herein. For example, the processor can execute comparison instructions to perform the operations described with reference to the comparator circuit 114. Furthermore, although two batteries 132, 134 are described for illustration, in other examples, one or more multi-battery management operations described herein can be applied to a different number of batteries, such as three or more batteries.

[0055] Referring to Figure 2, a specific illustrative example of the method is depicted and is generally designated as 200. In some examples, the operation of method 200 is performed by a portable device (such as portable device 100 in Figure 1).

[0056] Method 200 includes initiating a power-on operation at 202 via a handle switch. For example, power-on switch 106 may correspond to a handle switch of portable device 100. Power-on operation may be initiated in response to activation of power-on switch 106.

[0057] Method 200 further includes determining at 204 whether the difference in battery voltage levels satisfies a threshold. For example, the multi-battery management device 110 may determine whether a first voltage level V1 minus a second voltage level V2 or a second voltage level V2 minus a first voltage level V1 is less than or equal to a first threshold 116. In the non-limiting example of FIG2, the first threshold 116 may correspond to 0.7 volts (V). In other examples, the first threshold 116 may correspond to other values.

[0058] In response to determining that the difference meets the threshold (e.g., where the difference is greater than 0.7 V), method 200 further includes operating at 206 according to a single-cell discharge mode. For example, the first battery 132 can be coupled to one or more components 102 by activating the first switching device 124, and the second battery 134 can be decoupled from one or more components 102 by deactivating the second switching device 126.

[0059] The method further includes selectively activating the field-effect transistor (FET) of the high-voltage battery at 208 and deactivating the FET of the low-voltage battery. For example, in response to determining that a first voltage V1 is greater than a second voltage V2, a first switching device 124 can be activated and a second switching device 126 can be deactivated. In another example, in response to determining that a second voltage V2 is greater than a first voltage V1, a second switching device 126 can be deactivated and a first switching device 124 can be activated.

[0060] Alternatively, in response to determining that the difference does not meet the threshold (e.g., where the difference is less than or equal to 0.7 V), method 200 includes operating at 210 according to a multi-cell discharge mode. For example, the first cell 132 and the second cell 134 can each be coupled to one or more components 102 via a first switching device 124 and a second switching device 126, respectively.

[0061] Method 200 further includes determining at 212 whether the load current exceeds a threshold. For example, the multi-battery management device 110 may determine whether the magnitude of the current C1 meets a second threshold 118. In the non-limiting example of Figure 2, the second threshold 118 may correspond to 3-5 amperes (A). In other examples, the second threshold 118 may correspond to other values.

[0062] In response to the load current not exceeding the threshold, method 200 continues at 206. Alternatively, in response to the load current exceeding the threshold, method 200 includes activating the discharge FETs of both batteries at 214. For example, both the first switching device 124 and the second switching device 126 may be activated to couple the first battery 132 and the second battery 134 to one or more components 102.

[0063] One or more aspects described with reference to Figure 2 can improve the performance of a portable device. For example, selectively connecting and disconnecting the battery can improve its performance, reliability, or lifespan. As a specific example, by selectively disconnecting the battery, repeated charging and discharging of the battery by other batteries can be reduced or avoided. Therefore, for some battery technologies, battery life can be extended.

[0064] Furthermore, in some cases, selectively connecting or disconnecting batteries can enable a more "relaxed" matching process during the manufacture or assembly of portable devices. For example, by selectively connecting or disconnecting batteries to compensate for differences between them (e.g., charging capacity, charge rate, discharge rate, or impedance), the tolerances used for matching batteries can be relaxed. Alternatively or additionally, one or more testing operations in the matching process can be omitted, such as by omitting tests on the battery's charging capacity, charge rate, discharge rate, impedance, one or more other characteristics, or combinations thereof.

[0065] Figure 3 illustrates an illustrative configuration of the portable device 100. In the example of Figure 3, the portable device 100 corresponds to an electric lawnmower. In Figure 3, an electric motor 104 may be configured to operate the blades of the portable device 100. For example, the electric motor 104 may include a stator configured to receive a current C1 and generate an electromagnetic field based on the current C1. The electric motor 104 may further include a rotor configured to apply torque to a drive shaft in response to the electromagnetic field to rotate the blades.

[0066] In some aspects of this disclosure, the use of multiple switchable batteries in electric lawnmowers reduces or avoids certain disadvantages associated with electric lawnmowers that include batteries connected in series. For illustration, some conventional electric lawnmowers avoid battery-to-battery charging by implementing a power supply comprising multiple batteries connected in series. As a result, the output power increases (due to the increased voltage of the power supply), which may require redesigning one or more components to accommodate the increased voltage (e.g., by implementing a higher-power motor and control circuitry compatible with the increased voltage). By using switchable batteries connected in parallel according to some aspects of this disclosure, the output power of the electric lawnmower can be increased without redesigning to implement higher-power components (thus reducing the cost of the electric lawnmower), while reducing or avoiding battery-to-battery charging as in some conventional multi-battery designs.

[0067] Figure 4 illustrates another illustrative configuration of the portable device 100. In the example of Figure 4, the portable device 100 corresponds to an electric blower (e.g., a palm-sized electric blower or a wearable electric blower (such as a backpack-type electric blower)). In Figure 4, an electric motor 104 can be configured to operate the fan of the portable device 100. For example, the electric motor 104 can be configured to rotate the fan in response to a current C1. The rotation of the fan can draw air into the electric blower (e.g., due to the centrifugal force generated by the fan rotation), and the air can be compressed and discharged from the tube of the electric blower.

[0068] It is worth noting that the various values ​​and parameters described herein can have values ​​selected based on a specific application. For example, in the electric lawnmower embodiment of Figure 3, a battery with a higher voltage can be used compared to the electric blower embodiment of Figure 4. As an illustrative example, a battery voltage of 58 V can be used in the electric blower embodiment, while a battery voltage of 18 V can be used in the electric lawnmower embodiment. Furthermore, the values ​​of the first threshold 116 and the second threshold 118 can be selected based on a specific embodiment, such as based on the battery voltage. As an example, the illustrative thresholds described with reference to Figure 2 may be compatible with some embodiments but not with others.

[0069] In some aspects of this disclosure, the use of multiple switchable batteries in an electric blower reduces or avoids certain disadvantages associated with electric blowers that include batteries connected in series. For illustration, some conventional electric blowers avoid battery-to-battery charging by implementing a power supply comprising multiple batteries connected in series. As a result, the output power increases (due to the increased voltage of the power supply), which may require redesigning one or more components to accommodate the increased voltage (e.g., by implementing a higher-power motor and control circuitry compatible with the increased voltage). By using switchable batteries connected in parallel according to some aspects of this disclosure, the output power of the electric blower can be increased without redesigning to implement higher-power components (thus reducing the cost of the electric blower), while reducing or avoiding battery-to-battery charging as in some conventional multi-battery designs.

[0070] Figure 5 illustrates an example of a circuit that may be included in portable device 100. In some examples, the circuit of Figure 5 may correspond to or be included in the multi-battery management device 110 of Figure 1.

[0071] The circuit of Figure 5 may include a first drive circuit 510, a second drive circuit 520, and a microcontroller (MCU) 530. Figure 5 also depicts an illustrative, non-limiting example of a comparator circuit 540 (e.g., comparator circuit 114). In some examples, the first drive circuit 510, the second drive circuit 520, the MCU 530, and the comparator circuit 540 correspond to or are included in the multi-battery management device 110 of Figure 1. The circuit of Figure 5 may also include a first MCU write port circuit 560, an MCU power supply circuit 570, and a second MCU write port circuit 580.

[0072] In one example, the comparator circuit 540 includes a connection W1 to a first terminal (e.g., the positive terminal) of the first battery 132, and further includes a connection W5 to a second terminal (e.g., the negative terminal or ground terminal) of the first battery 132. The comparator circuit 540 may further include a connection W2 to a first terminal (e.g., the positive terminal) of the second battery 134, and may further include a connection W6 to a second terminal (e.g., the negative terminal or ground terminal) of the second battery 134.

[0073] In some examples, connections W1, W2, W5, and W6 are directly coupled to batteries 132 and 134. In this case, comparator circuit 540 is directly coupled to batteries 132 and 134 via connections W1, W2, W5, and W6. In other embodiments, comparator circuit 540 may be coupled to batteries 132 and 134 via sensor interface 112 of FIG. 1 and one or more battery sensors 136. As an illustrative example, in some embodiments, comparator circuit 540 includes digital circuitry that receives a digital representation of voltage levels V1 and V2 via sensor interface 112 and one or more battery sensors 136.

[0074] The comparator circuit 540 may further include connections W3, W4 coupled to one or more components 102. For example, connections W3, W4 may be coupled to the input terminals of the electric motor 104. In some examples, connection W3 is configured to supply current C1 to one or more components 102 (e.g., to the electric motor 104).

[0075] In Figure 5, the comparator circuit 540 further includes a first comparator U2A and a second comparator U2B. Further, the comparator circuit 540 may include or be coupled to a first switching device Q8 (e.g., first switching device 124) and a second switching device Q9 (e.g., second switching device 126). In some embodiments, each switching device Q8, Q9 includes a metal-oxide-semiconductor field-effect transistor (MOSFET), such as, by way of illustrative example, an enhancement-mode n-channel MOSFET. In other examples, each switching device Q8, Q9 may have a different configuration. Additionally, the comparator circuit 540 may include or be coupled to a first transient voltage suppressor diode (TVS1) and a second TVS diode (TVS2). In some examples, the switching devices Q8, Q9 and TVS diodes TVS1, TVS2 correspond to or are included in the control circuit 122 of Figure 1. In Figure 5, the switching devices Q8, Q9 and TVS diodes TVS1, TVS2 are coupled to the ground node GND.

[0076] In some examples, comparator circuit 540 is coupled to MCU 530. For example, the output of the first comparator U2A can be coupled to an input of MCU 530 (e.g., port "2"). As another example, the output of the second comparator U2B can be coupled to another input of MCU 530 (e.g., port "5"). The first comparator U2A can be configured to generate output BAT1_FB and provide output BAT1_FB to MCU 530. The second comparator U2B can be configured to generate output BAT2_FB and provide output BAT2_FB to MCU 530.

[0077] In some implementations, MCU 530 is coupled to drive circuits 510 and 520. For example, an output of MCU 530 (e.g., port "6") may be coupled to an input of the first drive circuit 510. As another example, another output of MCU 530 (e.g., port "7") may be coupled to an input of the second drive circuit 520. MCU 530 may be configured to provide a first control signal CTR_BAT_1 to the first drive circuit 510 and a second control signal CTR_BAT_2 to the second drive circuit 520.

[0078] The drive circuits 510 and 520 can be coupled to the switching devices Q8 and Q9. For example, the first drive circuit 510 may include an output coupled to the gate terminal of the first switching device Q8. The output of the first drive circuit 510 can be configured to provide a first battery enable signal BAT1_EN to the gate terminal of the first switching device Q8. As another example, the second drive circuit 520 may include an output coupled to the gate terminal of the second switching device Q9. The output of the second drive circuit 520 can be configured to provide a second battery enable signal BAT2_EN to the gate terminal of the second switching device Q9.

[0079] During operation, comparators U2A and U2B can compare the difference between voltage levels V1 and V2 with a reference voltage (e.g., a first threshold 116) and the current C1 with a reference current (e.g., a second threshold 118). Outputs BAT1_FB and BAT2_FB can indicate the results of the comparisons performed by comparators U2A and U2B. For example, outputs BAT1_FB and BAT2_FB can indicate whether the first difference (V1-V2) satisfies the first threshold 116, the second difference (V2-V1) satisfies the first threshold 116, and the current C1 satisfies the second threshold 118.

[0080] For example, the first output BAT1_FB can have either a first value or a second value. The first value can indicate that a first difference (e.g., V1-V2) meets a first threshold 116, and can further indicate that the magnitude of current C1 does not meet a second threshold 118. The second value can indicate that the first difference (e.g., V1-V2) does not meet the first threshold 116, or that the magnitude of current C1 meets the second threshold 118, or that both of the above occur. The first value can be associated with a single-cell mode using the first battery 132. The second value can be associated with a multi-cell mode using batteries 132 and 134.

[0081] As another example, the second output BAT2_FB can have one of a third or a fourth value. The third value can indicate that the second difference (e.g., V2-V1) meets a first threshold 116, and can further indicate that the magnitude of current C1 does not meet a second threshold 118. The fourth value can indicate that the second difference (e.g., V2-V1) does not meet the first threshold 116, or that the magnitude of current C1 meets the second threshold 118, or both. The third value can be associated with a single-cell mode using the second battery 134. The fourth value can be associated with a multi-cell mode using batteries 132 and 134.

[0082] In response to the outputs BAT1_FB and BAT2_FB, MCU 530 can select the operating mode of the multi-battery power supply 130 of Figure 1. For example, MCU 530 can use any of the techniques described herein to select a single-battery operating mode or a multi-battery operating mode. MCU 530 can generate specific values ​​for control signals CTR_BAT_1 and CTR_BAT_2 based on the selected operating mode of the multi-battery power supply 130 of Figure 1.

[0083] In response to control signals CTR_BAT_1 and CTR_BAT_2, drive circuits 510 and 520 can selectively activate or deactivate switching devices Q8 and Q9. For example, based on the value of the first control signal CTR_BAT_1, the first drive circuit 510 can activate or deactivate the first switching device Q8. Activating the first switching device Q8 can couple the first battery 132 to one or more components 102, while deactivating the first switching device Q8 can decouple the first battery 132 from one or more components 102 (e.g., by disconnecting the negative terminal of the first battery 132 from the ground node GND).

[0084] As another example, based on the value of the second control signal CTR_BAT_2, the second drive circuit 520 can activate or deactivate the second switching device Q9. Activating the second switching device Q9 can couple the second battery 134 to one or more components 102, and deactivating the second switching device Q9 can decouple the second battery 134 from one or more components 102 (e.g., by disconnecting the negative battery terminal of the second battery 134 from the ground node GND).

[0085] One or more aspects of Figure 5 enable selection between a single-battery operation mode and a multi-battery operation mode of the portable device 100. As a result, the power supplied to one or more components 102 can be selectively increased without requiring redesign of some high-voltage components (as in the case of some series-coupled battery designs), while reducing or avoiding battery-to-battery charging (as in the case of some conventional parallel-configured battery designs).

[0086] Figures 6A to 6I illustrate examples of circuitry that may be included in portable device 100. In Figures 6A to 6I, such circuitry includes a PM circuit 610, a bootstrap circuit 620, a driver circuit 630, a 15V circuit system 640, and a switch 650. In some examples, switch 650 may be used to implement a first switching device 124, a second switching device 126, or both. The circuitry in Figures 6A to 6I further includes a light-emitting diode (LED) port 655. In some examples, LED port 655 is included in a user interface or status light device of portable device 100.

[0087] The circuits in Figures 6A to 6I further include specific, non-limiting examples of the MCU 530. The circuits in Figures 6A to 6I further include a Hall effect or back electromotive force (Hall / BEMF) circuit 680 and a temperature sensing circuit (such as a negative temperature coefficient (NTC) circuit 690).

[0088] Figures 7A and 7B illustrate examples of devices that may be included in portable device 100. The devices of Figures 7A and 7B include a tilted printed circuit board assembly (PCBA) 710. The tilted PCBA 710 includes a tilt sensor 712 configured to generate an indication (“tilt sensing”) of the orientation (e.g., tilt) of the portable device 100. In one example, the tilt sensor 712 includes an optocoupler device.

[0089] The devices of Figures 7A and 7B further include an LED PCBA 720. The LED PCBA 720 can be configured to generate an indication of the battery status (“battery_check”) associated with the multi-battery power supply 130. The battery status indication can be used to remind the user to charge the portable device 100.

[0090] The devices of Figures 7A and 7B further include a handle key 730. The handle key 730 can be configured to activate or deactivate the portable device 100. For example, an on / off key 732 can selectively power on or off the portable device 100. A lock key 734 can selectively lock the portable device 100 in a power-off mode. In some examples, one or both of the on / off key 732 or the lock key 734 are included in the power-on switch 106 of Figure 1.

[0091] Although the invention and its advantages have been described in detail, it should be understood that various changes, substitutions, and modifications can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Furthermore, the scope of this application is not intended to be limited to the specific embodiments of the processes, machines, manufactures, compositions of matter, apparatuses, methods, and steps described in the specification. As will be readily understood by those skilled in the art from the disclosure of this invention, processes, machines, manufactures, compositions of matter, apparatuses, methods, or steps that are currently existing or will be developed in the future and perform substantially the same functions or achieve substantially the same results as the corresponding embodiments described herein can be utilized according to the invention. Therefore, the appended claims are intended to include such processes, machines, manufactures, compositions of matter, apparatuses, methods, or steps within their scope.

[0092] Furthermore, the scope of this application is not intended to be limited to the specific embodiments of the processes, machines, manufacturing, material composition, apparatus, methods and steps described in the specification.

[0093] 100: Portable devices 102: One or more components 104: Electric motor 106: Power switch 110: Multi-battery management device 112: Sensor Interface 114: Comparator Circuit 116: First threshold 118: Second threshold 120: Control signal 122: Control Circuit 124: First switching device 126: Second switching device 130: Multi-battery power supply 132: First Battery 134: Second Battery 136: One or more battery sensors 138: First Instruction 140: Second Instruction 142: Third Directive 200: Method 510: First driving circuit 520: Second drive circuit 530: MCU 540: Comparator Circuit 560: First MCU write port circuit 570: MCU power supply circuit 580: Second MCU write port circuit 610:PM circuit 620: Bootstrap Circuit 630: Driver circuit 650: Switch 655: LED Port 710: Tilted PCBA 712: Tilt Sensor 720: LED PCBA 730: Gamepad Buttons 732: On / Off Key 734: Lock key

[0094] none

Claims

1. A battery management method, the method comprising: Detecting a battery management trigger event at a portable device, the portable device including one or more components and a multi-battery power supply for supplying current to the one or more components, wherein the multi-battery power supply includes a first battery and at least a second battery coupled in parallel with the first battery; in response to detecting the battery management trigger event, determining a first voltage level of the first battery and a second voltage level of the at least second battery; based on the difference between the first voltage level of the first battery and the second voltage level of the at least second battery satisfying a first threshold and the magnitude of the current not satisfying a second threshold, disconnecting one of the first battery or the at least second battery from the one or more components, and using the other of the first battery or the at least second battery to power the one or more components of the portable device; and using the first battery and the at least second battery to power the one or more components of the portable device based on one or more of the following conditions: the difference between the first voltage level of the first battery and the second voltage level of the at least second battery does not satisfy the first threshold, or the magnitude of the current satisfies the second threshold.

2. The method as described in claim 1, further comprising selecting to disconnect the first battery based on the first voltage level being less than the second voltage level.

3. The method as described in claim 1, wherein, Detecting the battery management trigger event includes detecting the power-on event at the portable device.

4. The method as described in claim 1, wherein, The first battery is coupled to the one or more components via a first switching device, wherein at least the second battery is coupled to the one or more components via a second switching device.

5. The method as described in claim 4, wherein, Disconnecting the first battery or the at least second battery from the one or more components includes providing a control signal with a specific value to the first switching device or the second switching device.

6. The method as described in claim 1, wherein, The portable device includes an electric lawnmower or an electric blower, wherein one or more of the components include an electric motor.

7. The method as described in claim 1, further comprising receiving a first indication of the first voltage level, a second indication of the second voltage level, and a third indication of the current from one or more battery sensors of the portable device.

8. A multi-battery management device, comprising: A comparison circuit configured to determine whether the difference between a first voltage level of a first battery and a second voltage level of at least a second battery satisfies a first threshold, and to determine whether the magnitude of a current satisfies a second threshold, wherein the first battery and the at least second battery are included in a multi-battery power supply of a portable device, and wherein the multi-battery power supply is configured to provide the current to one or more components of the portable device; and a control circuit coupled to the comparison circuit, wherein the control circuit is configured to disconnect one of the first battery or the at least second battery from the one or more components and connect the other of the first battery or the at least second battery to the one or more components based on the first threshold being satisfied and the second threshold not being satisfied, and wherein the control circuit is further configured to couple the first battery and the at least second battery to the one or more components based on one or more of the following conditions: the difference between the first voltage level of the first battery and the second voltage level of the at least second battery does not satisfy the first threshold, or the magnitude of the current satisfies the second threshold.

9. The multi-battery management device as claimed in claim 8, further comprising a sensor interface coupled to the comparator circuit and configured to receive from one or more sensors of the portable device a first indication of a first voltage level of the first battery, a second indication of a second voltage level of the at least second battery, and a third indication of the current.

10. The multi-battery management device as described in claim 8, wherein, The control circuit is further configured to detect a battery management trigger event and, in response to the battery management trigger event, selectively couple the first battery and the at least second battery to the one or more components.

11. The multi-battery management device as described in claim 10, wherein, The battery management trigger event corresponds to the power-on event of the portable device, and further includes a power-on switch device configured to provide an indication of the power-on event to the control circuit.

12. The multi-battery management device as described in claim 8, wherein, The control circuit is further configured to disconnect the first battery from the one or more components based on the first voltage level being less than the second voltage level.

13. The multi-battery management device as described in claim 8, wherein, The control circuit includes: a first switching device coupled to the first battery and configured to selectively couple the first battery to the one or more components; and a second switching device coupled to the at least second battery and configured to selectively couple the at least second battery to the one or more components.

14. A battery management system, comprising: One or more sensors are configured to generate a first indication of a first voltage level of a first battery of the portable device, a second indication of a second voltage level of a second battery of the portable device, and a third indication of the magnitude of the current supplied by the first battery and the second battery to one or more components of the portable device. The device also includes a multi-battery management unit configured to: detect a battery management trigger event at the portable device; in response to detecting the battery management trigger event, determine a first voltage level of the first battery, a second voltage level of the second battery, and the magnitude of the current; disconnect one of the first battery or the second battery from the one or more components based on the difference between the first voltage level of the first battery and the second voltage level of the second battery satisfying a first threshold, and the magnitude of the current not satisfying a second threshold, and use the other of the first battery or the second battery to initiate power supply to the one or more components of the portable device; and use the first battery and the second battery to initiate power supply to the one or more components of the portable device based on one or more of the following conditions: the difference between the first voltage level of the first battery and the second voltage level of the second battery does not satisfy the first threshold, or the magnitude of the current satisfies the second threshold.

15. The battery management system as described in claim 14, wherein, The multi-battery management device is further configured to select to disconnect the first battery based on the first voltage level being less than the second voltage level.

16. The battery management system as described in claim 14, further comprising: A first switching device is coupled to the first battery and configured to selectively couple the first battery to the one or more components; And a second switching device coupled to the second battery and configured to selectively couple the second battery to the one or more components.

17. The battery management system as described in claim 16, wherein, The multi-battery management device is further configured to provide a control signal with a specific value to the first switching device or the second switching device to disconnect the first battery or the second battery from the one or more components.

18. The battery management system as described in claim 14, wherein, The multi-battery management device is further configured to detect a battery management trigger event and, in response to the battery management trigger event, selectively couple the first battery and the second battery to the one or more components.

19. The battery management system as described in claim 18, wherein, The battery management trigger event corresponds to the power-on event of the portable device, and further includes a power-on switch device configured to generate an indication of the power-on event.

20. The battery management system as described in claim 14, wherein, The one or more components include the electric motor of the portable device.

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