Method for Detecting Vehicle Battery Type Before Charging

Abstract

A method (200) performed by a battery charger (400) configured to charge a vehicle battery (430), the method comprising: charging (210) the vehicle battery (420) until a first measured voltage on the battery exceeds a first voltage threshold; stopping (220) charging during a third period; measuring (230) a second voltage on the battery at the end of the third period; determining (240) the battery type using a differential voltage and a set of predetermined conditions by calculating a difference between the first voltage threshold and the second voltage, wherein the predetermined conditions include (I)(I)

Description

[0001] The present invention relates to a method performed by a battery charger configured to charge a battery of a vehicle. In particular, the battery charger is configured to charge a starter battery of the vehicle. Background Art

[0002] Vehicles powered by combustion typically include a starter battery for cranking and starting the engine. Recently, batteries based on lithium starter batteries such as LiFePO 4 have been introduced as an alternative to lead-acid based starter batteries. Important advantages of lithium starter batteries include improved lifespan and performance. Lithium or LiFePO 4 batteries typically include four battery cells connected in series, which produce a total voltage comparable to that of a conventional lead-acid battery including six battery cells connected in series. Of particular importance is the fact that when the battery is fully charged, the characteristics of the battery are almost the same as its lead-acid counterpart. However, the method for optimally charging a lead-acid battery to a fully charged state may be different from the method for charging a lithium starter battery to a fully charged state.

[0003] Conventional battery chargers for vehicles have the following disadvantages: the charging mode must be manually selected to ensure the use of an appropriate charging method or algorithm. Selecting the wrong charging mode may result in an increase in charging time or even a shortening of the battery lifespan.

[0004] Another problem is that in some vehicles, the starter battery may be hidden or covered to such an extent that the user cannot easily determine the type of vehicle battery installed in the vehicle.

[0005] Therefore, there is a need for an improved method for charging a vehicle starter battery.

[0006] Object of the Invention

[0007] An object of embodiments of the present invention is to provide a solution that alleviates or solves the above disadvantages. Summary of the Invention

[0008] The above object is achieved by the subject matter described herein. Further advantageous implementations of the present invention are described herein.

[0009] According to a first aspect of the present invention, the object of the present invention is achieved by a method performed by a battery charger configured to charge a vehicle battery, the method comprising: charging the vehicle battery until a first measured voltage on the battery exceeds a first voltage threshold, stopping charging during a third period, measuring a second voltage on the battery at the end of the third period, using the differential voltage and a set of predetermined conditions to determine the battery type by calculating the difference between the first voltage threshold and the second voltage, wherein the predetermined conditions include:

[0010]

[0011] In an embodiment of the first aspect of the present invention, the method further includes selecting a charging mode using the determined battery type. At least one advantage of the first aspect of the present invention is that the charging time of the battery can be reduced. Another advantage is that the complexity of the process of charging the vehicle battery is reduced because it is not necessary to indicate the battery type, especially at a relatively high SoC.

[0012] According to a second aspect of the present invention, the object of the present invention is achieved by a method performed by a battery charger configured to charge a vehicle battery, the method including: charging the vehicle battery by providing current to the battery being charged, repeating the previous step until a first measured voltage on the battery exceeds a first voltage threshold, charging the vehicle battery during a second period, stopping charging during a third period, measuring a second voltage on the battery, determining a differential voltage by calculating a difference between the first voltage threshold and the second voltage, using the differential voltage and a set of predetermined conditions to determine the battery type, where the predetermined conditions include

[0013]

[0014] In an embodiment of the method according to the second aspect of the present invention, the method further includes selecting a charging mode using the determined battery type.

[0015] The advantages of the second aspect of the present invention are at least the same as those of the first aspect of the present invention.

[0016] According to a third aspect of the present invention, the object of the present invention is achieved by a method performed by a battery charger configured to charge a vehicle battery, the method including: charging the vehicle battery, using the battery voltage level measured over time to determine a trajectory, and determining the battery type of the vehicle battery by comparing the determined trajectory with a set of criteria.

[0017] In an embodiment of the method according to the third aspect of the present invention, the set of criteria compares characteristics of the determined trajectory with characteristics of a set of predetermined trajectories.

[0018] In an embodiment of the method according to the third aspect of the present invention, the characteristics of the set of predetermined trajectories indicate a region formed by a predetermined trajectory and a constant SoC level, and where determining the battery type of the vehicle includes determining that the determined trajectory falls within the region.

[0019] In an embodiment of the method according to the third aspect of the present invention, the characteristics of the set of predetermined trajectories indicate the shape of a predetermined trajectory, and where determining the battery type of the vehicle includes determining that the determined trajectory matches the shape of the predetermined trajectory.

[0020] In an embodiment of the method according to the third aspect of the present invention, if the trajectory meets the criterion that the shape of the determined trajectory matches a predetermined trajectory indicating a decreasing slope value and an increasing battery voltage level, the battery type of the vehicle battery is determined to be LiFePO4 / lithium battery.

[0021] In an embodiment of the method according to the third aspect of the present invention, the battery type of the vehicle battery is determined to be LiFePO4 / lithium battery only when the slope value decreases at a decreasing rate higher than a predefined threshold.

[0022] In an embodiment of the method according to the third aspect of the present invention, if the trajectory meets the criterion of a trajectory indicating a slope value lower than 0.1 volts per hour and the corresponding measured battery voltage level value is in the range of [13.3V - 13.4V], the battery type of the vehicle battery is determined to be LiFePO4 / lithium battery.

[0023] In an embodiment of the method according to the third aspect of the present invention, if the trajectory meets the criterion of a trajectory indicating a slope value lower than 0.25 volts per hour and the corresponding measured battery voltage level value is in the range of [13.5V - 13.65V], the battery type of the vehicle battery is determined to be LiFePO4 / lithium battery.

[0024] In an embodiment of the method according to the third aspect of the present invention, the method further includes using the determined battery type to select a battery charging mode.

[0025] At least one advantage of the third aspect of the present invention is that the charging time of the battery can be reduced. Another advantage is that the complexity of the process of charging the vehicle battery is reduced because it is not necessary to indicate the battery type, especially at low to medium SoC.

[0026] According to a fourth aspect of the present invention, the object of the present invention is achieved by a method performed by a battery charger configured to charge a vehicle battery, the method comprising:

[0027] Obtaining (1010) a plurality of determined battery types of the vehicle battery using different methods according to any one of claims 1 - 2, 3 - 4 or 5 - 13.

[0028] If the plurality of determined battery types are the same or if most of the determined battery types are the same, selecting (1020) a normal battery charging mode, or if the plurality of determined battery types are different or if most of the determined battery types are not the same, selecting a safe battery charging mode,

[0029] Charging (1030) the vehicle battery using the selected battery mode.

[0030] At least one advantage of the fourth aspect of the present invention is that the charging time of the battery can be reduced. Another advantage is that the complexity of the process of charging the vehicle battery is reduced, since it is not necessary to indicate the battery type regardless of the SoC of the battery.

[0031] According to a fifth aspect of the present invention, the object of the present invention is achieved by a battery charger comprising a processing circuit, a memory, the memory comprising computer-executable instructions which, when executed on a processing unit comprised in the battery charger, are for causing the battery charger to perform any of the method steps according to any one of the first, second, third or fourth aspects of the present invention.

[0032] The advantages of the fifth aspect are at least the same as the advantages of the first to fourth aspects of the present invention.

[0033] According to a fifth aspect of the present invention, the object of the present invention is achieved by a computer program, providing the computer program and the computer program comprising computer-executable instructions which, when executed on a processing unit comprised in the battery charger, are for causing the battery charger to perform any of the methods according to the first, second, third or fourth aspects of the present invention.

[0034] According to a sixth aspect of the present invention, the object of the present invention is achieved by a computer program product, providing the computer program product and the computer program product comprising a computer-readable storage medium having implemented therein the computer program according to the fifth aspect.

[0035] The scope of the present invention is defined by the claims, which are incorporated by reference into this part. By considering the following detailed description of one or more embodiments, a more complete understanding of the embodiments of the present invention, as well as the recognition of its additional advantages, will be provided to those skilled in the art. Reference will be made to the accompanying drawings which will be briefly described first. Description of the Drawings

[0036] Figure 1 The charge / discharge curves of a lithium starter battery and a lead-acid starter battery are shown respectively.

[0037] Figure 2 A flowchart of a method performed by a battery charger configured to charge a vehicle battery according to one or more embodiments of the present disclosure is illustrated.

[0038] Figure 3 A flowchart of a method performed by a battery charger configured to charge a vehicle battery according to one or more embodiments of the present disclosure is illustrated.

[0039] Figure 4Shows a battery charger according to an embodiment of the present disclosure.

[0040] Figure 5 Illustrates an example of a trajectory according to one or more embodiments of the present disclosure.

[0041] Figure 6 Shows trajectories of different battery charging currents / charging times according to one or more embodiments of the present disclosure.

[0042] Figure 7 Illustrates details of different trajectories and corresponding SoC levels.

[0043] Figure 8 Shows a graph with slope values and corresponding SoC values.

[0044] Figure 9 Illustrates a flowchart of a method performed by a battery charger configured to charge a vehicle battery according to one or more embodiments of the present disclosure.

[0045] Figure 10 Illustrates a flowchart of method 1000 performed by battery charger 400 configured to charge a vehicle battery.

[0046] By considering the following detailed description of one or more embodiments, a more complete understanding of the embodiments of the present invention, as well as the realization of its additional advantages, will be provided to those skilled in the art. It should be understood that like reference numerals are used to identify like elements illustrated in one or more of the figures. Detailed Description

[0047] In general, all terms used herein will be interpreted according to their ordinary meaning in the relevant technical field, unless clearly given and / or implied a different meaning from the context in which the terms are used. All references to an / one / the element, apparatus, component, method, step, etc. will be construed openly as referring to at least one instance of the element, apparatus, component, method, step, etc., unless otherwise explicitly stated. The steps of any method disclosed herein need not be performed in the exact order disclosed, unless the steps are explicitly described as after or before another step and / or where it is implicit that a step must be after or before another step. In appropriate cases, any feature of any embodiment disclosed herein can be applied to any other embodiment. Similarly, any advantage of any embodiment can be applied to any other embodiment, and vice versa. Other objects, features, and advantages of the appended embodiments will be apparent from the following description.

[0048] As used in this specification and the corresponding claims, "or" shall be understood to cover the mathematical OR of "and" and "or", and shall not be understood as XOR (exclusive or). The indefinite article "a" in this disclosure and the claims is not limited to "one", and may also be understood as "one or more", i.e., plural.

[0049] The term state of charge or SoC as used herein represents the state of charge of a battery relative to the maximum capacity of the battery, and is typically given as a percentage value of the maximum capacity of the battery. For example, SoC = 0% represents an empty battery, while SoC = 100% means a fully charged battery capable of delivering the maximum capacity of the battery.

[0050] The term "trace" as used herein represents a trace or path that intersects coordinates (such as a value pair) in a coordinate system (such as a two-dimensional plane formed by the slope of the charge / discharge curve ΔU / Δt and the voltage level U of the charged battery).

[0051] Figure 1 The charge / discharge curves 101, 102 of a lithium starter battery (such as LiFePO 4 ) and the charge / discharge curves 103, 104 of a lead-acid (LA) starter battery are shown respectively. The voltage at the poles of the battery or the battery voltage is shown on the vertical axis, and the state of charge (SoC) is shown on the horizontal axis. As can be seen from Figure 1 , in order to distinguish a lithium battery from a lead-acid battery, it is necessary to know both the measured voltage and the SoC. In other words, simply measuring the voltage at the poles of the battery is not sufficient to distinguish a lithium battery from a lead-acid battery. The voltage at the poles of the battery will be affected by any load connected to the battery in the vehicle. Such load and SoC of the battery are usually unknown to the battery charger connected to the battery. Therefore, relying solely on the charge / discharge curve to determine the battery type lead-acid / lithium is problematic. In other words, when distinguishing a lithium battery from a lead-acid battery, simply measuring the voltage at the poles of the battery and comparing it with the charge / discharge curve will provide unreliable results.

[0052] As can be seen from Figure 1 , the charge / discharge curves 101, 102 related to lithium batteries and the charge / discharge curves 103, 104 related to lead-acid batteries differ the most in the range of [10% - 80%] SoC or [10% - 70%] SoC. However, especially for vehicle batteries used as starter batteries, charging usually starts at a relatively high SoC (such as > 80% SoC or for example > 70% SoC). This more ideal range of [10% - 80%] SoC for using the charge / discharge curve to distinguish a lithium starter battery from a lead-acid starter battery is usually not available for analysis because the SoC usually exceeds 80%.

[0053] One aspect of the present disclosure provides the advantages of being able to distinguish between lithium starter batteries and lead-acid starter batteries at relatively high SoC levels (such as [10%-70%] SoC or [85%-98%] SoC).

[0054] This aspect of the method presented herein is based on the recognition that lithium batteries (such as LiFePO 4 batteries) have a slower electrochemical response after being subjected to a current pulse. The time taken for a lead-acid battery to stabilize its voltage after being subjected to a current pulse is significantly shorter than that of the corresponding lithium battery. As can be seen from Figure 1 it, the voltage on the lead-acid battery is also higher than that on the lithium battery within the same range in the [85%-98%] SoC range.

[0055] Figure 2 A flowchart of a method 200 performed by a battery charger 400 configured to charge a vehicle battery is illustrated. This method is particularly suitable when determining the type of battery (e.g., lead-acid or lithium) and then charging the battery based on that determination, especially when charging the battery at relatively high SoC levels (such as, >70% SoC or [85%-98%] SoC).

[0056] In one embodiment, there is provided a method 200 performed by a battery charger 400 configured to charge a vehicle battery, the method 200 including:

[0057] Step 210: Charge the vehicle battery until a first measured voltage at the battery or at the poles of the battery exceeds a first voltage threshold U 1 . The charging can be performed, for example, by supplying a constant current I 1 to the battery or a current pulse having an amplitude I 1 . The first voltage threshold U 1 can be selected from the charging curve within the [85%-98%] SoC range. In one example, U 1 can be selected to be 14.2 V or 14.4 V.

[0058] Optionally, the method further includes charging the vehicle battery at a constant voltage equal to the first voltage threshold U 2 within a second time period t 1 . In one example, the second time period t 2 can be selected within the range of [1 - 120] seconds, preferably within the range of [30 - 90] seconds, and most preferably within the range of [45 - 75] seconds (e.g., 60 seconds).

[0059] Step 220: Optionally stop charging within a third time period t 3 . In other words, allow the battery to be in the third time period t3 Take a rest. In one embodiment, the third period t 3 can be selected to be equal to zero, i.e., there is actually no charging stop before proceeding to step 230. In one embodiment, the third period t 3 can be selected to be equal to or greater than the typical stabilization time of a lead-acid battery, i.e., the time taken for the voltage to stabilize after being subjected to a current pulse. t 3 is also selected to be shorter than the typical stabilization time of the corresponding lithium battery, i.e., the time typically taken for the voltage on the lithium starter battery to stabilize after being subjected to a current pulse. In one example, the third period t 3 can be selected in the range of [1 - 120] seconds, preferably in the range of [15 - 45] seconds, and most preferably in the range of [20 - 40] seconds (e.g., 30 seconds).

[0060] Step 230: Measure the second voltage U on the poles of the battery or batteries at the end of the third period t 3 . In other words, measure the second voltage U on the battery after the rest / relaxation in the previous step 2 . 2 .

[0061] Step 240: Use the differential voltage U 1 -U 2 and a set of predetermined conditions to determine the battery type. It should be understood that the battery type is determined for the vehicle battery.

[0062] The predetermined conditions may include

[0063]

[0064] An example of U 1 is 14.4V. Separately, an example of U Pb is 1.2V, and an example of U Li is 0.8V. Another example of U Pb is 0.7V, and another example of U Li is 0.6V.

[0065] Optionally, the method further includes selecting a battery charging mode using the determined battery type. This step of selecting the battery charging mode may also involve charging the battery. This may involve charging the battery in a lead-acid battery mode if a lead-acid battery type is determined, charging the battery in a lithium-ion battery mode if a lithium-ion battery type is determined, or charging the battery in a safe mode if an unknown battery type is determined. The safe mode may involve charging the battery with a voltage that is safe for both the lead-acid battery type and the lithium-ion battery type. In one example, a maximum charging voltage of 13.8 volts or 14.4 volts is used in the lead-acid battery mode and the safe mode, and a maximum charging voltage of 14.6 volts or 14.8 volts is used in the lithium-ion battery mode.

[0066] Another aspect of the present disclosure also provides a method that has the advantage of being able to distinguish a lithium starter battery from a lead-acid starter battery at relatively high SoC levels (such as [70%-98%] SoC or [85%-98%] SoC). Variations of the method described below are Figure 2 described.

[0067] Figure 3 A flowchart of a method 300 performed by a battery charger 400 configured to charge a vehicle battery is illustrated. In an embodiment, the vehicle battery may be a vehicle starter battery. The method includes:

[0068] Step 310: Charge the vehicle battery by providing a current I 1 to the battery being charged.

[0069] Providing current I 1 may include providing a current pulse having an amplitude I 1 . The current I 1 may initially be selected / set to 20 amperes. The amplitude I 1 is typically constant, and thus the charging method is typically constant-current charging at this stage.

[0070] Step 320: Repeat step 310 until a first measured voltage at the battery or at the poles of the battery exceeds a first voltage threshold U 1 . The voltage threshold U 1 may be set to 14.2 V or 14.4 V. In one embodiment, charging the vehicle battery further includes the steps of measuring the voltage at the battery or at the poles of the battery over time, and / or adapting the current by increasing the current I 1 in 5-ampere steps if a downward trend in the voltage at the battery is detected. The steps of measuring the battery voltage and / or adapting the current are repeated during the duration of step 320.

[0071] The voltage threshold U 1It can be, for example, a voltage that is the same as a predetermined constant voltage level of the charger, where the absorption phase of the charging process will be activated.

[0072] Optional step 330: Stop charging within the first time period t 1 The first time period t 1 can be set to a value in the interval [0 - 60 seconds], preferably set to 1 minute. This step can be omitted in its entirety.

[0073] Step 340: Charge the vehicle battery within the second time period t 2 by, for example, using a constant voltage (e.g., at a threshold U 1 of 14.2 / [CPA1]14.4 volts). Charging can be performed using a constant voltage of 14.4 volts without restricting the charging current I 2 , or by allowing the battery charger to deliver current up to its maximum capacity. In other words, the method also includes charging the vehicle battery by supplying a constant voltage (e.g., 14.4 volts) to the battery. Optionally, the method also includes charging the vehicle battery by supplying a current or a constant current I 2 or a current pulse with an amplitude I 2 (usually the maximum current that the battery charger can supply).

[0074] Optional step 341: Stop charging within the third time period t 3 In other words, allow the battery to rest within the time period t 3 The third time period t 3 can be set / selected to a value in the range of [0 - 120], [15 - 60 seconds], preferably 30 seconds. Optionally, the third time period t 3 can be set / selected to zero (0) seconds, thus effectively eliminating step 341.

[0075] Step 350: Measure the second voltage U 2 on the battery or the poles of the battery. The second voltage is typically measured after step 340 and / or after 341 and at the end of t 3 The second voltage U 2 can also be saved to a memory, for example, saved to the memory of the battery charger.

[0076] Step 360: Determine the differential voltage U 1 by calculating the difference between the voltage threshold and the second voltage (U 2 - U diff ).

[0077] Step 370: Use the differential voltage and a set of predetermined conditions to determine the battery type. The predetermined conditions can include

[0078]

[0079] Typical values of the quantities given in this document (such as U 1 , U 2 , U Pb , U Li , t 2 and t 3 ) can be selected, for example, from:

[0080] U 1 = 14.2 / 14.4 V, set, for example, by the properties of the charger (such as the trigger voltage for the absorption phase).

[0081] U 2 is measured during the charging process, and U 2 can be, for example, in the range of [13.7 - 13.8 V].

[0082] U Pb = 0.7 V

[0083] U Li = 0.6 V

[0084] t 2 = 60 s

[0085] t 3 = 30 s

[0086] The reason for introducing an unknown battery type is that if a significant load of 50 - 60 amperes is coupled to the battery, the method will not be able to distinguish between lithium batteries and lead - acid batteries with sufficient reliability, thus determining the unknown battery type.

[0087] Optional step 380: Use the determined battery type to select a charging mode. This may involve charging the battery in lead - acid battery mode if a lead - acid battery type is determined, charging the battery in lithium - battery mode if a lithium - battery type is determined, or charging the battery in a safe mode if an unknown battery type is determined. The safe mode may involve charging the battery with a voltage that is safe for both lead - acid battery types and lithium - battery types. In other words, after the type of the battery has been determined, use a method depending on the determined battery type to charge the vehicle battery.

[0088] In one example, the lithium - battery mode uses a maximum charging voltage higher than the lead - acid battery mode. For example, the lithium - battery mode uses a charging voltage that > 14.4 V.

[0089] Respectively, an example of U 1 is 14.4 V. An example of U Pb is 1.2 V, and an example of U Li is 0.8 V.

[0090] Figure 4 FIG. 400 shows a battery charger according to an embodiment of the present disclosure.

[0091] It should be understood that the battery charger 400 may be provided with necessary coupling means, such as clamps and connectors, which are configured to electrically couple the charger 400 to the battery 420.

[0092] The battery charger 400 may be in the form of a charger for a vehicle starter battery 420. The battery charger 400 may include processing circuitry 412 optionally communicatively coupled to a communication interface 404 for wired and / or wireless communication. Additionally, the battery charger 400 may further include at least one optional antenna (not shown in the figures). The antenna may be coupled to a transceiver of the communication interface 404 and is configured to transmit and / or emit and / or receive wireless signals in a wireless communication system, such as sending / receiving voltage values. In one example, the processing circuitry 412 may be any selection of processors and / or central processing units and / or processor modules and / or multiple processors configured to cooperate with each other. Additionally, the battery charger 400 may further include a memory 415. The memory 415 may contain instructions executable by the processing circuitry to perform any of the methods and / or method steps described herein.

[0093] The communication interface 404, such as a wireless transceiver and / or a wired / wireless communication network adapter, is configured to send data values or parameters as signals to the processing circuitry 412 or receive data values or parameters from the processing circuitry 412, send to or receive data values or parameters from other external nodes, other external nodes such as a central parameter server providing any of the parameters given above (such as U 1 、U 2 、U Pb 、U Li 、t 1 、t 2 and t 3 ). In an embodiment, the communication interface communicates directly between communication network nodes or via a communication network.

[0094] In one or more embodiments, the battery charger 400 may further include an input device 417, which is configured to receive input or indication from a user and send a user input signal indicating the user input or indication to the processing circuitry 412. The input device 417 may be used to receive any of the parameters given above as input from the user.

[0095] In one or more embodiments, the battery charger 400 may further include a display 418 configured to receive a display signal from the processing circuit 412 indicative of a rendered object, such as text or a graphical user input object, and display the received signal as an object, such as text or a graphical user input object. The display may be used to display any of the parameters given above or any measured voltage described above.

[0096] In one or more embodiments, the battery charger 400 may further include a controllable power source 419 configured to output voltage and / or current to the starter battery 420 in response to a control signal received from the processing circuit 412. The controllable power source may be any power source available in the art capable of regulating the output voltage and / or output current.

[0097] In one embodiment, the display 418 is integrated with the user input device 417 and is configured to receive a display signal from the processing circuit 412 indicative of a rendered object, such as text or a graphical user input object, and display the received signal as an object, such as text or a graphical user input object, and / or is configured to receive input or indication from the user and send a user input signal indicative of the user input or indication to the processing circuit 412.

[0098] In an embodiment, the processing circuit 412 is communicatively coupled to the memory 415 and / or the communication interface 404 and / or the input device 417 and / or the display 418 and / or one or more sensors (not shown in the figure) (e.g., a voltage sensor capable of measuring the voltage on the connected vehicle / starter battery) and / or the controllable power source 419.

[0099] In an embodiment, the communication interface and / or transceiver 404 communicates using wired and / or wireless communication technologies. In an embodiment, one or more memories 415 may include a selection of hard RAM, disk drives, floppy disk drives, tape drives, optical disk drives, CD or DVD drives (R or RW), or other removable or fixed media drives.

[0100] In additional embodiments, the battery charger 400 may further include and / or be coupled to one or more additional sensors (not shown) configured to receive and / or obtain and / or measure physical properties related to the vehicle battery 420 and / or the battery charger 400 and send one or more sensor signals indicative of the physical properties to the processing circuit 412, such as sensor data indicative of the battery voltage.

[0101] The battery charger can be in the form of any one of a standalone battery charger, a battery charger integrated into a vehicle, an on-board computer, an electronic control unit (ECU), a digital information display, a fixed computing device, a laptop computer, a tablet computer, a handheld computer, a wrist-worn computer, a smartwatch, a PDA, a smartphone, an in-vehicle computer system, or a navigation device.

[0102] In one embodiment, a computer program is provided, and the computer program includes computer-executable instructions that, when executed on a processing unit included in the battery charger 400, cause the battery charger 400 to perform any of the method steps described herein.

[0103] In one embodiment, a computer program is provided, and the computer program includes computer-executable instructions that, when executed on a processing unit included in the battery charger, cause the battery charger to perform any of the method steps described herein.

[0104] In one embodiment, a computer program product is provided, and the computer program product includes a computer-readable storage medium having embodied therein any of the above computer programs.

[0105] In one embodiment, a carrier containing any of the above computer programs, wherein the carrier is one of an electrical signal, an optical signal, a radio signal, or a computer-readable storage medium.

[0106] In an embodiment, the communication network communicates using wired or wireless communication technologies, and the wired or wireless communication technologies may include at least one of the following: local area network (LAN), metropolitan area network (MAN), global system for mobile communications (GSM), enhanced data GSM environment (EDGE), universal mobile telecommunications system, long term evolution, high speed downlink packet access (HSDPA), wideband code division multiple access (W-CDMA), code division multiple access (CDMA), time division multiple access (TDMA), Wi-Fi, voice over Internet protocol (VoIP), LTE-Advanced, IEEE 802.16m, Wireless MAN-Advanced, evolved high speed packet access (HSPA+). 3GPP long term evolution (LTE), Mobile WiMAX (IEEE 802.16e), ultra mobile broadband (UMB) (formerly evolved data optimized (EV-DO) Rev.C), fast low latency access with seamless handover orthogonal frequency division multiplexing (Flash-OFDM), high capacity space division multiple access and mobile broadband wireless access (MBWA) (IEEE 802.20) systems, high performance wireless metropolitan area network (HIPERMAN), wavelength division multiple access (BDMA), worldwide interoperability for microwave access (Wi-MAX), and ultrasonic communication, etc., but not limited thereto.

[0107] In addition, those skilled in the art will recognize that the battery charger 400 may include necessary communication capabilities in the form of, for example, functions, devices, units, elements, etc. for implementing the present solution. Examples of other such devices, units, elements, and functions are: processors, memories, buffers, control logics, encoders, decoders, rate matchers, de-rate matchers, mapping units, multipliers, decision units, selection units, switches, interleavers, de-interleavers, modulators, demodulators, inputs, outputs, antennas, amplifiers, receiver units, transmitter units, DSPs, MSDs, encoders, decoders, power supply units, feeders, communication interfaces, communication protocols, etc., which are appropriately arranged together for implementing the present solution.

[0108] In particular, the processor and / or processing device of the present disclosure may include one or more instances of processing circuits, processor modules, and multiple processors configured to cooperate with each other, central processing units (CPUs), processing units, processing circuits, processors, application specific integrated circuits (ASICs), microprocessors, field programmable gate arrays (FPGAs), or other processing logics that can interpret and execute instructions. Thus, the expressions "processor" and / or "processing device" may represent a processing circuit including multiple processing circuits, such as any, some, or all of the processing circuits mentioned above. The processing device may also perform data processing functions for input, output, and processing of data, including data buffering and device control functions, such as call processing control, user interface control, etc.

[0109] Another aspect of the present disclosure provides the advantage of being able to distinguish a lithium starter battery from a lead-acid starter battery at relatively low to medium levels of SoC (such as [10%-70%] SoC or [10%-80%] SoC).

[0110] This aspect of the method proposed herein is based on the recognition that in the main part of the SoC range of 10%-85%, the slope ΔU / Δt of the charge / discharge curve of the lead-acid battery over time is significantly higher than that of the lithium battery. See Figure 1 the examples disclosed in. In this aspect of the method, based on the difference in the slope of the charge / discharge curve, the lithium starter battery can be distinguished from the lead-acid starter battery at relatively low to medium levels of SoC (such as [10%-70%] SoC).

[0111] In other words, one of the key differences between different battery types with relatively low to medium levels of SoC proposed by the present disclosure is the slope of the voltage profile during battery charging. See, for example, Figure 1 . First, in the main part of the SoC region, for example, 10% - 85% SoC, the slope ΔU / Δt of the voltage curve of the lead - acid system is significantly higher. Second, the voltage level U of the LiFePO4 battery in the low - to - medium part of the SoC region, for example, 10% - 70% SoC, is significantly higher compared to the voltage level U of the corresponding lead - acid battery, as Figure 1 can be seen. If the slope of the charge / discharge curve ΔU / Δt is estimated periodically during charging, it will form a trajectory in the two - dimensional plane of ΔU / Δt versus the battery voltage U as charging progresses. In other words, the trajectory forms a path or trace of value pairs in the two - dimensional plane formed by the slope ΔU / Δt and the charged battery voltage level U.

[0112] Figure 5 Illustrates examples of trajectories 511, 512, 521, 522 according to one or more embodiments of the present disclosure. Trajectories of four different cases are illustrated. The trajectories are illustrated by thicker lines. The narrower lines correspond to constant values of SoC 531, 532, 541, 542 for each type of battery, where the lower part of the line corresponds to slow charging / low charging current, and the upper part of the line corresponds to fast charging / high charging current.

[0113] Illustrates two lead - acid trajectories 511, 512 and two lithium / LiFePO4 trajectories 521, 522. Trajectory 511 illustrates the trajectory of a lead - acid battery at a low charging current level / long charging time. Trajectory 512 illustrates the trajectory of a lead - acid battery at a high charging current level / short charging time. Trajectory 521 illustrates the trajectory of a lithium battery at a low charging current level / long charging time. Trajectory 522 illustrates the trajectory of a lithium battery at a high charging current level / short charging time.

[0114] The above - mentioned trajectories extend from left to right in the figure because the SoC level increases with the passage of time during the charging process.

[0115] As can be seen in Figure 5 , Figure 5 is an example based on experimental data. The first region is formed by the trajectories 511, 512 and the constant values of SoC 531, 532. The second region is formed by the trajectories 521, 522 and the constant values of SoC 541, 542. The positions of these regions in the two - dimensional plane are different, and according to the present disclosure, this can be used to distinguish and / or determine the type (lead - acid or lithium) of the battery being charged.

[0116] As in Figure 5As can be further seen, the shape of the trace / path of the trajectory is different, and according to the present disclosure, this can be used to distinguish and / or determine the type of battery being charged (lead-acid or lithium).

[0117] In other words, the difference in the characteristics of the trajectory can be used to distinguish and / or determine the type of battery being charged (lead-acid or lithium). This is further described in the following section. A determined trajectory falling within the region formed by the constant values of the trajectories 511, 512 and the SoC 531, 532 can be determined as a lead-acid vehicle battery. A determined trajectory falling within the region formed by the constant values of the trajectories 521, 522 and the SoC 541, 542 can be determined as a lead-acid vehicle battery.

[0118] Figure 6 Trajectories of different battery charging currents / charging times according to one or more embodiments of the present disclosure are shown.

[0119] The present disclosure is at least partially based on the recognition that one of the key differences in the behavior between two battery types, lead-acid and lithium, is the characteristic of the voltage curve, such as the charge / discharge curve or charge / discharge profile during charging, as shown with respect to Figure 1 as shown.

[0120] First, for lead-acid batteries in the main part of the SoC region, the slope ΔU / Δt of the voltage curve is significantly higher. Second, during charging, the battery voltage level U of LiFePO4 / lithium batteries is significantly higher than that of lead-acid batteries. If the slope of the voltage curve ΔU / Δt is estimated during the charging of the battery, as charging progresses, it will form a trajectory in the plane of ΔU / Δt relative to U. With respect to Figure 5 the trajectory is further described.

[0121] The present disclosure proposes that by estimating / determining the slope ΔU / Δt of the voltage curve over time based on the corresponding (e.g., measured) battery voltage level U, it is possible to distinguish between lead-acid batteries and LiFePO4 / lithium batteries in the low to middle part of the SoC region (such as [10%-70%] SoC).

[0122] Figure 6 Trajectories of five different charging current levels / charging times are shown, ranging from a 610-hour charge for 10 hours, a 620-hour charge for 7.14 hours, a 630-hour charge for 5.10 hours, a 640-hour charge for 3.63 hours to a 650-hour charge for 2.6 hours. In this example, the trajectories are related to a 60 ampere-hour LiFePO4 / lithium battery. As can be seen, these trajectories 610-650 are characterized in that when the battery is being charged, these trajectories 610-650 form several more or less sharp maxima and minima.

[0123] These characteristics of the trajectory are in sharp contrast to those of a lead - acid battery, where the lead - acid trajectory follows a smoother path / trace with a steadily increasing slope across the voltage region / range. For example, the quota ΔU 2 / Δt 2 is always positive with respect to U.

[0124] The present disclosure utilizes these contrasts or differences in the characteristics of the trajectories to determine the type of battery being charged, which is typically either a lead - acid battery or a lithium - ion battery. Additionally, when the slope ΔU / Δt is plotted with respect to SoC rather than with respect to voltage U, the extreme points in the lithium - ion battery trajectory approximately occur at the same SoC levels. This is further described Figure 8 below.

[0125] In one exemplary embodiment, a technique for determining the battery type (e.g., lead - acid or lithium) or differentiating between the two battery types (e.g., lead - acid or lithium) in the low - to - medium SoC region can be performed in the following manner.

[0126] In a first alternative step, a function of a lead - acid battery that depends on two variables ΔU / Δt and U is obtained or provided. This function gives or provides the SoC value for a particular value pair [ΔU / Δt, U]. The function can be obtained, provided, or created by using curve - fitting techniques, such as by curve - fitting experimental data including triples of slope values, battery voltage values, and SoC values ([ΔU / Δt, U, SoC]) to a cubic polynomial function. The experimental data can be obtained, for example, by charging a number of batteries and measuring / recording the experimental data. Then, the function will be configured to provide the SoC value for a given value pair [ΔU / Δt, U].

[0127] The function can have the following form:

[0128]

[0129] where K 1 、K 2 、…K 10 are coefficients that can be determined by using standard least - squares fitting methods commonly described in the literature. Additionally or alternatively, any curve - fitting technique known to those skilled in the art can be used.

[0130] The resulting region / surface formed or bounded by the trajectory and a constant SoC level is illustrated in Figure 7 where different trajectories and constant SoC levels are shown.

[0131] In addition, due to the characteristics of the LiFePO4 / Li battery, the corresponding function of the LiFePO4 / Li battery, which is similar to the function of the lead-acid battery described above, is created more complexly due to the irregular behavior of the characteristics. See, for example, Figure 6 . When attempting to provide a function for the LiFePO4 / Li battery that can provide an SoC value for each given value pair [ΔU / Δt, U], normal curve fitting techniques cannot provide satisfactory results.

[0132] Instead, the present disclosure proposes to identify specific voltage ranges of the battery voltage level U, which can be applied to the trajectory to determine the battery type. These voltage ranges include some very obvious differences between the characteristics of the lead-acid battery trajectory and the LiFePO4 / Li trajectory, such as Figure 1 shown in. In other words, by measuring the battery voltage level over time and determining the slope ΔU / Δt of each measured voltage level, the trajectory can be determined. Effectively, determining the trajectory involves plotting the trajectory as a trace / path / curve in a two-dimensional plane, where the slope value ΔU / Δt forms one axis, and the battery voltage or battery voltage level U forms the second axis, as further illustrated with respect to Figure 5 . Therefore, it is possible to separate the trajectories of each battery type, such as the LiFePO4 / Li or lead-acid battery type.

[0133] In one example, if the trajectory meets the criteria of a decreasing slope value and an increasing battery voltage level, the battery type of the vehicle battery is determined to be a lithium battery. In some embodiments, this involves evaluating one or more criteria only within the identified / obtained voltage range. The identified / obtained voltage range can be, for example, predefined and includes the battery voltage level range [13.3V - 13.4V] and / or the battery voltage level range [13.45 - 13.6V].

[0134] In the battery voltage level range [13.3V - 13.4V], during the charging of the LiFePO4 / Li battery, at a specific battery voltage level U, the rate of voltage tilt ΔU / Δt is greatly reduced. When charging a lead-acid battery, this characteristic of the trajectory is not obviously seen, and this characteristic can be used to distinguish between a charging LiFePO4 / Li battery and a charging lead-acid battery. The same is true for the battery voltage level U range [13.3V - 13.4V]. See, for example, Figure 6 .

[0135] In a similar manner, within the battery voltage level range [13.3V - 13.4V], during the charging of a LiFePO4 / lithium battery, at a specific battery voltage level U, the rate of voltage tilt ΔU / Δt is significantly reduced. Alternatively or additionally, this can be used to distinguish a charging LiFePO4 / lithium battery from a charging lead-acid battery.

[0136] In another example, if a trajectory meets the criterion that the slope value is lower than a threshold within a predetermined voltage range, the battery type of the vehicle battery is determined to be a lithium battery. In some embodiments, this involves evaluating one or more criteria only within the identified voltage range. If the trajectory meets the criterion of a trajectory indicating a slope value lower than 0.1 volts per hour and the corresponding measured battery voltage level value U is within the range of [13.3V - 13.4V], the battery type of the vehicle battery can be determined to be a lithium battery. Alternatively or additionally, if the trajectory meets the criterion of a trajectory indicating a slope value lower than 0.25 volts per hour and the corresponding measured battery voltage level value is within the range of [13.3V - 13.4V], the battery type of the vehicle battery is determined to be a lithium battery.

[0137] As described above, when charging the battery at a relatively low to medium SoC level (e.g., below about 70%), the method described Figure 6 is particularly suitable.

[0138] Figure 7 Details of different trajectories 610 - 650 and corresponding SoC levels 700 - 770 are illustrated. The slope ΔU / Δt of the trajectory is shown on the vertical axis. The battery voltage level value U of the trajectory is shown on the horizontal axis.

[0139] Trajectories 610 - 650 of a lead-acid battery at different charging current rates are shown, corresponding to charging times from 2.6 hours for trajectory 650 to 10 hours for trajectory 610. The SoC levels are indicated by thinner lines. Constant SoC values are indicated by thicker lines. In other words, the slope value ΔU / Δt forms one axis of a two-dimensional plane, and the battery voltage U forms the second axis of the two-dimensional plane.

[0140] Figure 8 A graph showing slope values and corresponding SoC values is illustrated. The slope value ΔU / Δt is shown on the vertical axis, and the corresponding SoC value is shown on the horizontal axis. As can be seen from Figure 8 where the slope values and corresponding SoC values are plotted, for different charging currents 810 - 850, the extreme points of the curve approximately occur at the same SoC level. In the example shown in Figure 8 the extreme points of the curve occur within SoC range 1 and SoC range 2.

[0141] Figure 9 FIG. 900 is a flow chart of a method 900 performed by a battery charger 400 configured to charge a vehicle battery. The method is particularly suitable when the battery type (e.g., Led or lithium) is determined at a relatively low or medium level of SoC (such as [10%-70%] SoC) and the battery is charged thereafter based on that determination.

[0142] In one embodiment, there is provided a method 900 performed by a battery charger 400 configured to charge a vehicle battery, the method comprising:

[0143] Step 910: Charge the vehicle battery 420. The charging can be performed, for example, by supplying a constant current I to the battery 420 1 or a current pulse having an amplitude I 1 Alternatively or additionally, the charging can be performed, for example, by supplying a dynamically variable current I to the battery 1 or a current pulse having an amplitude I 1 Alternatively or additionally, the charging of the vehicle battery can be performed according to any suitable method known in the art (e.g., constant voltage charging).

[0144] Step 920: Determine a trajectory using the battery voltage level measured over time. The battery voltage level is typically measured directly over time while charging the vehicle battery 420, and / or the battery voltage level is a statistical aggregation (such as an average) of the measured battery voltage levels, or a predefined and / or stored charge / discharge curve. The trajectory can typically indicate, for example, a trace or path in a two-dimensional plane that intersects with a value pair of the slope value of the measured battery voltage level and the corresponding measured battery voltage level value as described with respect to Figures 5 - 7 Determining the trajectory can involve, for example, plotting the trajectory as a curve in a two-dimensional plane by connecting the value pairs with a line, where the slope value ΔU / Δt forms one axis and the corresponding battery voltage or battery voltage level U forms a second axis, as further shown with respect to Figure 5 , Figure 6 or Figure 7 as further shown.

[0145] In one example, the slope or slope value is determined based on the measured battery voltage level (e.g., the directly measured battery voltage level or the battery voltage level retrieved from memory as a historical measurement), for example, a voltage curve such as a charge curve. When the battery is being charged, the measured battery voltage level indicates the battery voltage and / or the voltage across the poles of the battery and / or the battery voltage level of a particular battery type.

[0146] In a non - limiting example, an initial voltage value is determined at an initial time point, and successive voltage values are determined at successive time points. Then, for example, a slope value can be determined according to the following relationship:

[0147]

[0148] It should be understood that the slope value can also be determined based on multiple voltage values and multiple successive time points, for example, by forming a statistical metric such as an average. Alternatively, any suitable method for determining the slope value available to those skilled in the art can be used.

[0149] Then, a value pair can be formed or determined as:

[0150] Value pair 连续 =(slope value 连续 , successive voltage value)

[0151] where is the value pair 连续 is a successive value pair, the slope value 连续 is a previously determined slope value, and the successive voltage value is the current battery voltage value, for example, the most recently measured battery voltage value.

[0152] Step 930: Determine the battery type of the vehicle battery by comparing the determined trajectory with a set of criteria.

[0153] In one embodiment, the set of criteria compares the characteristics of the determined trajectory with the characteristics of a set of predetermined trajectories.

[0154] In one embodiment, the characteristics of the set of predetermined trajectories indicate a region / zone / surface formed by the predetermined trajectories and a constant SoC level, and wherein determining the battery type of the vehicle includes determining that the determined trajectory falls within the region / zone / surface formed by the predetermined trajectories. This is further described with respect to Figure 5 Further description.

[0155] Alternatively or additionally, the characteristics of the set of predetermined trajectories indicate the shape of the predetermined trajectories, and wherein determining the battery type of the vehicle includes determining that the determined trajectory matches the shape of the predetermined trajectories. This can include determining a path / trace in the case where the trajectory has a specific shape (e.g., has a steadily increasing slope across the voltage region / range, e.g., a quota ΔU 2 / Δt 2 is always positive with respect to U). Further description of determining the battery type based on the shape of the trajectory is provided with respect to Figure 6 Further description of determining the battery type based on the shape of the trajectory.

[0156] In one embodiment, if the trajectory meets the criterion that the shape of the determined trajectory matches a predetermined trajectory indicating a decreasing slope value ΔU / Δt and an increasing battery voltage level U, the battery type of the vehicle battery 420 is determined to be LiFePO4 / lithium battery. Alternatively, the battery type of the vehicle battery is determined to be LiFePO4 / lithium battery only when the slope value ΔU / Δt decreases at a decreasing rate higher than a predefined threshold. If the trajectory does not meet the criterion that the shape of the determined trajectory matches a predetermined trajectory indicating a decreasing slope value ΔU / Δt and an increasing battery voltage level U, the vehicle battery 420 may be determined to be an LA battery.

[0157] In one embodiment, if the trajectory meets the trajectory criterion indicating that the slope value ΔU / Δt is lower than 0.1 volts per hour and the corresponding measured battery voltage level value U is in the range of [13.3V - 13.4V], the battery type of the vehicle battery 420 is determined to be a lithium battery. If the trajectory does not meet the criterion, the vehicle battery 420 may be determined to be an LA battery.

[0158] In one embodiment, if the trajectory meets the trajectory criterion indicating that the slope value ΔU / Δt is lower than 0.25 volts per hour and the corresponding measured battery voltage level value U is in the range of [13.5V - 13.65V], the battery type of the vehicle battery 420 is determined to be a lithium battery. If the trajectory does not meet the criterion, the vehicle battery 420 may be determined to be an LA battery.

[0159] Optionally, the method further includes:

[0160] Optional step 950: Use the determined battery type to select a battery charging mode.

[0161] Optional step 960: Charge the vehicle battery using the selected battery mode.

[0162] Selecting the battery charging mode may involve: charging the battery in a lead-acid battery mode if a lead-acid battery type is determined, charging the battery in a lithium battery mode if a lithium battery type is determined, or charging the battery in a safe mode if an unknown battery type is determined. The safe mode may involve charging the battery with a voltage that is safe for both lead-acid battery types and lithium battery types. In one example, a maximum charging voltage of 13.8 volts is used in the lead-acid battery mode and the safe mode, and a maximum charging voltage of 14.6 volts is used in the lithium battery mode.

[0163] Another aspect of the present disclosure provides the advantage of being able to distinguish between lithium starter batteries and lead-acid starter batteries, with increased safety at low, medium, and high SoC of the vehicle battery.

[0164] Figure 10The flowchart of method 1000 performed by battery charger 400 configured to charge a vehicle battery is illustrated.

[0165] In one embodiment, a method performed by a battery charger 400 configured to charge a vehicle battery is provided, the method comprising:

[0166] Step 1010: Obtain multiple determined battery types of the vehicle battery using different methods. Generally, the multiple determined battery types are obtained by performing any method described with respect to Figure 2 and / or Figure 3 and / or Figure 9 For example, using any result from step 240, step 370, or step 930.

[0167] Step 1020: If the multiple determined battery types are the same, select a normal battery charging mode, or if the multiple determined battery types are different, select a safe battery charging mode. Alternatively or additionally, if most of the determined battery types are the same, a normal battery charging mode may be selected, or if most of the determined battery types are not the same, a safe battery charging mode is selected.

[0168] Step 1030: Charge the vehicle battery using the selected battery mode.

[0169] In one example, this may involve: charging the battery in a lead-acid battery mode if most of the determined battery types are lead-acid batteries, charging the battery in a lithium-ion battery mode if most of the determined battery types are lithium-ion batteries, or charging the battery in a safe mode if no majority is determined.

[0170] In one example, the method described with respect to Figure 2 determines that a lithium-ion battery is being charged, and the method described with respect to Figure 9 determines that a lead-acid battery is being charged.

[0171] The safe mode may involve charging the battery with a voltage that is safe for both lead-acid battery types and lithium-ion battery types. In one example, a maximum charging voltage of 14.4 volts is used in the lead-acid battery mode and the safe mode, and a maximum charging voltage of 14.6 volts is used in the lithium-ion battery mode.

[0172] Finally, it should be understood that the present invention is not limited to the above embodiments, but also relates to and encompasses all embodiments within the scope of the appended independent claims.

[0173] Enumerated embodiments

[0174] Example 1. A method performed by a battery charger 400 configured to charge a vehicle battery, the method comprising: charging the vehicle battery until a measured voltage on the battery or an electrode of the battery exceeds a voltage threshold U 1 ,

[0175] stopping charging within a third time period t 3 ,

[0176] measuring a second voltage U on the battery or an electrode of the battery at the end of the time period t 3 , 2 ,

[0177] using a differential voltage U 1 -U 2 and a set of predetermined conditions to determine the battery type, wherein the predetermined conditions include

[0178]

[0179] Example 2. The method according to Example 1, further comprising using the determined battery type to select a charging mode.

[0180] Example 3. A flowchart of a method 200 performed by a battery charger 400 configured to charge a vehicle battery, the method comprising:

[0181] Step 310: Charge the vehicle battery by providing a current I1.

[0182] Step 320: Repeat step 210 until a first measured voltage on the battery or an electrode of the battery exceeds a voltage threshold U1.

[0183] Optional step 330: Stop charging within a first time period t1.

[0184] Step 340: Charge the vehicle battery by providing a current I1 within a second time period t2.

[0185] Optional step 340: Stop charging within a third time period t3. In other words, allow the battery to rest within the time period t3.

[0186] Step 350: Measure a second voltage U2 on the battery or an electrode of the battery. The second voltage U2 is typically measured after step 240 and at the end of t3. The second voltage U2 can be stored in a memory.

[0187] Step 360: Determine a differential voltage U by calculating U1 - U2 diff

[0188] Step 370: Use the differential voltage and a set of predetermined conditions to determine the battery type. The predetermined conditions may include

[0189]

[0190] Optional step 380: Select a charging mode using the determined battery type. This may involve: if a lead-acid battery type is determined, charging the battery in lead-acid battery mode, if a lithium-ion battery type is determined, charging the battery in lithium-ion battery mode, or if an unknown battery type is determined, charging the battery in a safe mode. The safe mode may involve charging the battery with a voltage that is safe for both lead-acid battery types and lithium-ion battery types.

[0191] Respectively, U 1 An example of is 14.4V. U Pb An example of is 1.2V, and U Li An example of is 0.8V. U Pb Another example of is 0.7V and U Li Another example of is 0.6V.

Claims

1. A method (200) performed by a battery charger (400) configured to charge a vehicle battery (420), the vehicle battery (420) being at a relatively high 85%-98% SoC level, the method comprising: charging (210) the vehicle battery (420) until a first measured voltage on the battery exceeds a first voltage threshold selected from a charging curve within the 85%-98% SoC range, Stop charging (220) during period t 3 where the period t 3 is selected within the range of 1 - 120 seconds, and the period t 3 is selected to be equal to or greater than the typical stabilization time of a lead-acid battery At the end of the time period t 3 measure (230) a second voltage on the battery By calculating the difference U between the first voltage threshold and the second voltage diff to determine (240) the battery type using the differential voltage and a set of predetermined conditions, where the predetermined conditions include: where U diff is the difference between the first voltage threshold and the second voltage, where U Pb , U Li is a predetermined threshold value.

2. The method according to claim 1, further comprising selecting a charging mode using the determined battery type and charging the vehicle battery (420).

3. A method (300) performed by a battery charger (400) configured to charge a vehicle battery (420), selecting a first voltage threshold from a charging curve within the 85%-98% SoC range, the method comprising: charging (310) the vehicle battery by supplying current to the battery being charged, repeating (320) the previous step (310) until a first measured voltage on the battery exceeds the first voltage threshold, charging (340) the vehicle battery during a second period, stopping (341) charging during a third period t3, where the third period t3 is selected within the range of 1 - 120 seconds and the third period t3 is selected to be equal to or greater than the typical stabilization time of a lead-acid battery, measuring (350) a second voltage on the battery, determining (360) a differential voltage by calculating a difference voltage between the first voltage threshold and the second voltage, using the differential voltage and a set of predetermined conditions to determine the battery type, where the predetermined conditions include where U diff is the difference between the first voltage threshold and the second voltage, where U Pb , U Li is a predetermined threshold value.

4. The method according to claim 3, wherein the method further comprises selecting a charging mode using the determined battery type.

5. A method (900) performed by a battery charger (400) configured to charge a vehicle battery (420), the vehicle battery (420) being at a relatively low to medium level of 10%-70% SoC, the method comprising: charging (910) the vehicle battery (420); determining (920) a trajectory using battery voltage levels measured over time, where the trajectory includes value pairs, where the value pairs include a charge / discharge curve slope ΔU / Δt and a battery voltage level U, and the trajectory forms a path or trace of value pairs in a two-dimensional plane formed by the slope ΔU / Δt and the charged battery voltage level U, determining (930) the battery type of the vehicle battery (420) by comparing the determined trajectory with a set of criteria, where the set of criteria compares characteristics of the determined trajectory with characteristics of a set of predetermined trajectories, the characteristics of the set of predetermined trajectories indicating regions / zones / surfaces formed by the predetermined trajectories and constant SoC levels, and where determining the battery type of the vehicle includes determining that the determined trajectory falls within the regions / zones / surfaces formed by the predetermined trajectories.

6. A method (900) performed by a battery charger (400) configured to charge a vehicle battery (420), the vehicle battery (420) being at a relatively low to medium level of 10%-70% State of Charge (SoC), the method comprises: charging (910) the vehicle battery (420); using the battery voltage level measured over time to determine (920) a trajectory, wherein the trajectory comprises value pairs, and wherein the value pairs comprise a charge / discharge curve slope ΔU / Δt and a battery voltage level U, and the trajectory forms a path or trace of value pairs in a two-dimensional plane formed by the slope ΔU / Δt and the charged battery voltage level U; determining (930) the battery type of the vehicle battery (420) by comparing the determined trajectory with a set of criteria, wherein the set of criteria compares the characteristics of the determined trajectory with the characteristics of a set of predetermined trajectories; wherein the characteristics of the set of predetermined trajectories indicate the shape of the predetermined trajectories, and wherein determining the battery type of the vehicle comprises determining that the determined trajectory matches the shape of the predetermined trajectory, and wherein a path / trace is determined in the case where the trajectory has a specific shape, wherein: if the trajectory meets the criteria that the shape of the determined trajectory matches a predetermined trajectory indicating a decreasing slope value and an increasing battery voltage level, the battery type of the vehicle battery (420) is determined to be a lithium battery, or if the trajectory does not meet the criteria, the vehicle battery (420) is determined to be a lead-acid battery.

7. The method according to claim 6, wherein the battery type of the vehicle battery is determined to be a lithium battery only when the slope value decreases at a decreasing rate higher than a predefined threshold.

8. The method according to claim 6, wherein if the trajectory meets the criteria of the trajectory indicating a slope value lower than 0.1 volts per hour and the corresponding measured battery voltage level value is in the range of 13.3V - 13.4V, the battery type of the vehicle battery (420) is determined to be a lithium battery, or if the trajectory does not meet the criteria, the vehicle battery (420) is determined to be a lead-acid battery.

9. The method according to claim 6 or 8, wherein if the trajectory meets the criteria of the trajectory indicating a slope value lower than 0.25 volts per hour and the corresponding measured battery voltage level value is in the range of 13.5V - 13.65V, the battery type of the vehicle battery (420) is determined to be a lithium battery, or if the trajectory does not meet the criteria, the vehicle battery (420) is determined to be a lead-acid battery.

10. The method according to any one of claims 5 - 9, wherein the method further comprises selecting a battery charging mode using the determined battery type and charging the vehicle battery (420).

11. A method (1000) performed by a battery charger (400) configured to charge a vehicle battery (420), the method comprises: Use the method according to any one of claims 1-4 to obtain (1010) a plurality of determined battery types of the vehicle battery, wherein the battery types are determined using differential voltages, If the plurality of determined battery types are the same or if most of the determined battery types are the same, select (1020) a normal battery charging mode, wherein the normal battery charging mode is a mode selected from a lead-acid battery mode or a lithium-ion battery mode, or If the plurality of determined battery types are different or if most of the determined battery types are not the same, select a safe battery charging mode, Charge (1030) the vehicle battery using the selected battery mode.

12. A method (1000) performed by a battery charger (400) configured to charge a vehicle battery (420), the method comprising: Use the method according to any one of claims 5-10 to obtain (1010) a plurality of determined battery types of the vehicle battery, wherein the battery types are determined using a trajectory, If the plurality of determined battery types are the same or if most of the determined battery types are the same, select (1020) a normal battery charging mode, wherein the normal battery charging mode is a mode selected from a lead-acid battery mode or a lithium-ion battery mode, or If the plurality of determined battery types are different or if most of the determined battery types are not the same, select a safe battery charging mode, Charge (1030) the vehicle battery using the selected battery mode.

13. A battery charger (400), comprising: A processing circuit (412), A memory (415) including computer-executable instructions that, when executed on the processing circuit (412) included in the battery charger (400), cause the battery charger (400) to perform any one of the method steps according to any one of claims 1-12.

14. A computer program product comprising a computer-readable storage medium having computer-executable instructions that, when executed on a processing unit included in a battery charger (400), cause the battery charger (400) to perform any one of the method steps according to claims 1-12.

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