Compensation method for measurement errors in a battery management system

Abstract

The present disclosure relates to methods of compensation for measurement errors in battery management systems. Techniques for voltage measurement of battery cells in a battery management system (BMS) are described. Raw voltage measurements can include errors caused by ohmic losses from cable impedance and other elements in the BMS. The techniques include performing a calibration cycle to generate correction values based on the measured response of discharge switches under different states. The techniques also include scaling the correction values at runtime to correct for filter response errors in bulk measurements.

Description

[0001] Claiming priority

[0002] This patent application claims priority to U.S. Provisional Patent Application Serial No. 63 / 313238, filed February 23, 2022, entitled “Method for Compensating Measurement Errors in a Battery Pack Management System,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to battery management systems (BMS), and in particular to compensation for measurement errors. Background Technology

[0004] Electric vehicles (EVs) are becoming increasingly popular. One challenge in adopting EVs is battery maintenance. A battery management system (BMS) can be used to monitor different operating conditions of the battery, such as those used in EVs. Typically, a BMS can be used to measure conditions such as voltage and surface temperature.

[0005] For example, a BMS can use specialized hardware to sense battery voltage and load individual cells into a battery stack to maintain battery health, maximize energy use, and minimize safety hazards. However, the hardware used by a BMS may introduce ohmic losses, leading to voltage measurement errors. Summary of the Invention

[0006] One aspect of this disclosure provides a method for compensating measurement errors in a battery pack management system, the method comprising: performing a calibration cycle to calculate a set of correction factors, the calibration cycle comprising: disabling one or more discharge switches in the battery pack management system; performing a first measurement based on disabling the one or more discharge switches; enabling the one or more discharge switches in the battery pack management system; performing a second measurement based on enabling the one or more discharge switches; and determining the set of correction factors based on the first and second measurements; receiving an original voltage measurement; and applying at least one correction factor from the set of correction factors to generate a compensated voltage measurement.

[0007] Another aspect of this disclosure provides a battery pack management system, including: at least one hardware processor; and at least one memory storing instructions that, when executed by the at least one hardware processor, cause the at least one hardware processor to operate, the operation including: performing a calibration cycle to calculate a set of correction factors, the calibration cycle including: disabling one or more discharge switches in the battery pack management system; performing a first measurement based on disabling the one or more discharge switches; enabling the one or more discharge switches in the battery pack management system; performing a second measurement based on enabling the one or more discharge switches; and determining the set of correction factors based on the first and second measurements; receiving a raw voltage measurement; and applying at least one correction factor from the set of correction factors to generate a compensated voltage measurement.

[0008] Another aspect of this disclosure provides a machine-readable medium containing instructions that, when executed by a machine, cause the machine to perform operations including: performing a calibration cycle to calculate a set of correction factors, the calibration cycle including: disabling one or more discharge switches in the battery pack management system; performing a first measurement based on disabling the one or more discharge switches; enabling one or more discharge switches in the battery pack management system; performing a second measurement based on enabling the one or more discharge switches; and determining the set of correction factors based on the first and second measurements; receiving a raw voltage measurement; and applying at least one correction factor from the set of correction factors to generate a compensated voltage measurement. Attached Figure Description

[0009] The accompanying drawings illustrate only exemplary embodiments of this disclosure and should not be construed as limiting its scope.

[0010] Figure 1 A block diagram of a wireless battery pack management system is shown.

[0011] Figure 2 A block diagram of a wired battery pack management system is shown.

[0012] Figure 3 An example section of a voltage measurement system is shown.

[0013] Figure 4 The battery voltage diagram of the battery pack is shown.

[0014] Figures 5A-5B An example portion of the circuit diagram for a voltage measurement system is shown.

[0015] Figure 6 A flowchart illustrating the method for determining cable impedance is shown.

[0016] Figure 7 A flowchart illustrating the method for determining the voltage gain factor is shown.

[0017] Figure 8 A graph showing the battery voltage and scaled IIR response is provided.

[0018] Figure 9A A portion of the lookup table for the step response of an IIR filter unit with a CT increment of 1 is shown.

[0019] Figure 9B A portion of a scaled-down lookup table for the step response of an IIR filter unit with a CT increment of 4 is shown.

[0020] Figure 10 A flowchart of a method 1000 for generating voltage measurements with error compensation is shown.

[0021] Figure 11 A battery voltage graph showing the calibrated voltage measurement during continuous measurement is shown. Detailed Implementation

[0022] Voltage measurement techniques for battery cells in a battery pack management system (BMS) are described. Raw voltage measurements may include errors caused by cable impedance and ohmic losses from other components in the BMS. Voltage measurement techniques include performing calibration cycles to generate correction values ​​based on measurement responses of the discharge switch in different enabled / disabled states. These techniques also include scaling the correction values ​​during runtime to correct for filter response errors in volumetric measurements.

[0023] This document discloses a method for compensating measurement errors in a battery pack management system. The method includes performing a calibration cycle to calculate a set of correction factors, the calibration cycle comprising: disabling one or more discharge switches in the battery pack management system; performing a first measurement based on disabling the one or more discharge switches; enabling the one or more discharge switches in the battery pack management system; performing a second measurement based on enabling the one or more discharge switches; and determining the set of correction factors based on the first and second measurements. The method also includes receiving a raw voltage measurement and applying at least one correction factor from the set of correction factors to generate a compensated voltage measurement.

[0024] The voltage measurement techniques described in this article can be used with wired BMS, wireless BMS (WBMS), or a combination thereof. Figure 1 A block diagram of WBMS 100 is shown. WBMS 100 may include multiple battery pack modules 102.1-102.n, each battery pack module including multiple battery cells. For example, battery pack modules 102.1-102.n may be lithium-ion battery packs. Battery packs of different specifications, sizes, and shapes can be used. Each module can be coupled to a corresponding monitor 104.1-104.n. WBMS 100 may also include a network manager 110 and an electronic control unit (ECU) 114.

[0025] Each monitor 104.1-104.n may include one or more BMS monitors 106 and wireless nodes 108. The BMS monitor 106 may be coupled to the battery pack module and may monitor various states or performance characteristics of the battery pack module. The BMS monitor 106 may be provided as an integrated circuit, which may include monolithic integrated BMS circuitry or an integrated module comprising multiple integrated circuit dies or other circuit elements within a common shared integrated circuit device package, as an illustrative example.

[0026] The BMS monitor 106 may include various sensors. The BMS monitor 106 can sample the battery pack voltage to monitor the battery pack level. The BMS monitor can also monitor the current and external surface temperature of the battery pack modules.

[0027] BMS monitor 106 can be coupled to wireless node 108 via a communication interface, such as a Serial Peripheral Interface (SPI). Both BMS monitor 106 and wireless node 108 can be mounted on a single printed circuit board (PCB). Wireless node 108 may include a wireless system-on-a-chip, which may include a radio transceiver to transmit battery measurements to network manager 110 via a wireless network. In one example, wireless node 108 may include a Functionally Safe (FuSa) central processing unit (CPU) to process certain battery pack condition measurements.

[0028] Network manager 110 may include one or more wireless SoCs 112.1-112.2 for communication with monitors 104.1-104.n. Network manager 110 may be coupled to ECU 114 and packaged level sensor 120 via their respective communication interfaces (e.g., SPI). ECU 114 may include BMS application 116 and WBMS interface library 118 to control the operation of WBMS 100.

[0029] Figure 2 A block diagram of a wired BMS 200 is shown. The wired BMS 200 may include multiple BMS monitors 202.1-202.n and a network manager 204. (See above reference.) Figure 1 The BMS monitor 202.1-202.n can include various sensors. The BMS monitor 202.1-202.n can sample the battery pack voltage to monitor the battery pack level. The BMS monitor 202.1-202.n can also monitor the current and external surface temperature of the battery pack module.

[0030] In this example, BMS monitors 202.1-202.n can communicate with network manager 204 via a wired communication interface. For example, the wired communication interface may include an isolated (transformer) communication cable, such as implementing an Isolated Serial Peripheral Interface (SPI). The communication cable can be connected serially from one module to another, for example, in a daisy-chain from one monitor to another, where the last monitor provides a termination point for the cable.

[0031] BMS monitors can continuously sample battery voltages to provide more effective noise filtering and reduce (or eliminate) aliasing errors. However, continuous sampling can introduce challenges such as measurement errors. Most systems can share discharge and measurement leads, and cable impedance can cause measurement errors when attempting to measure and discharge battery cells simultaneously.

[0032] Figure 3 An example portion of a voltage measurement system associated with a BMS having continuous sampling is shown. As shown, package assembly 302 includes battery pack cells 304 and corresponding cable impedance 306. The package assembly can be coupled to circuitry 308, which can be provided as a printed circuit board (PCB), such as a flexible PCB. Circuitry 308 may include a filter / discharge network 310 and a voltage sensor 312. Filter / discharge network 310 may include discharge and sensing lines. Voltage sensor 312 may include multiple analog-to-digital converters to measure the voltage response of the individual cells of battery pack cells 304. The impedance of the discharge and sensing lines, as well as the cable, introduces measurement errors. Even small impedances can lead to significant measurement errors. For example, the discharge / sensing lines in circuitry 308 can introduce series impedances of up to 1-2 ohms, which can result in measurement errors of hundreds of millivolts.

[0033] Figure 4 A battery voltage diagram of the battery pack is shown, illustrating the sources of measurement error caused by the activation of the discharge switch during continuous measurement. Figure 4 The diagram shows battery voltage on the y-axis and time on the x-axis for two battery voltage measurements (e.g., C4 and C5). As shown, the battery voltage has a DC offset, which depends on the enabled discharge switch. These offsets contribute to measurement errors. Furthermore, before reaching steady state with these offset values, the battery voltage includes a gyration error (e.g., the slope of the DC steady-state offset) caused by the performance of the filters used in the voltage measurements.

[0034] Next, techniques for compensating for measurement errors are described. Techniques for compensating for discharge voltage errors and techniques for scaling this voltage error compensation to account for the filter response are described.

[0035] In the first method, referred to herein as impedance calculation technique, the cable impedance, which causes measurement errors due to its ohmic losses, can be directly calculated using measurements taken with the discharge switch enabled and disabled in a specified manner. As described in further detail below, the first method may include several calibration steps and allows for flexible use of the discharge switch, and it provides the BMS with information about the system impedance status.

[0036] In a second approach, known as the voltage gain technique, the gain factor can be calculated using measurements taken with the discharge switch enabled and disabled in a specific manner using a selected discharge configuration. Compared to the first approach, the second approach can have a shorter calibration procedure and requires fewer computational resources for different measurement cycles, but it can include recalibration in response to changes in the discharge switch configuration.

[0037] Both methods involve calibration variations to account for changes in system impedance. The calibration frequency can be determined by the system integrator based on temperature dependence analysis and to compensate for measurement accuracy. Furthermore, as described in further detail below, after determining the correction factor using the first or second method, the correction factor can be scaled to account for variations in the filter response, such as that of a filter used for voltage measurements.

[0038] The techniques described herein for compensating for measurement errors can be executed by one or more processors associated with the BMS. For example, as mentioned above, these techniques can be executed by a BMS application in an ECU.

[0039] Figure 5A An example portion of the circuit diagram of a voltage measurement system 500 is shown. For simplicity and brevity, two channels of the voltage measurement system 500 are shown here, but the voltage measurement system may include more than two channels (e.g., 16 channels). Each channel can measure the voltage response of a battery in a battery pack. Two battery packs, Bx and Bx+1, are shown. In the first channel, Bx can be coupled to cable impedances Rcable1 and Rcable2. A discharge switch Rd can be coupled to cable impedances Rcable1 and Rcable2. An ADC (analog-to-digital converter) Cx can be provided to measure the voltage response of the first battery pack battery Bx. In the second channel, Bx+1 can be coupled to cable impedances Rcable2 and Rcable3. A discharge switch Rd+1 can be coupled to cable impedances Rcable1 and Rcable2. An ADC Cx+1 can be provided to measure the voltage response of the second battery pack battery Bx+1. Cable impedances Rcable1, Rcable2, and Rcable3 may introduce errors in the voltage measurement due to their unknown impedances. Therefore, these additional cable impedances can cause voltage drops in voltage measurements.

[0040] Impedance calculation techniques address measurement errors by calculating the impedance (primarily wiring impedance) introduced into the system between the circuit (e.g., circuit 308) and the battery pack (e.g., battery pack 304). By calculating the impedance, the state of the discharge switch can be used to calculate the losses introduced into the system and applied to measurements during operation. In impedance calculation techniques, these cable impedances can be directly calculated using measurements taken when the discharge switch is enabled and disabled in a specific manner.

[0041] Figure 6 A flowchart of method 600 for determining cable impedance is shown. In operation 602, discharge switches Rd and Rd+1 are disabled (e.g., open), and voltage measurement is performed using the ADC Cx of battery Bx. Here, because the discharge switches are disabled, there is no voltage drop across the cable impedance, and Cx = Bx.

[0042] In operation 604, discharge switch Rd+1 is enabled (e.g., closed), while discharge switch Rd remains disabled, and voltage measurements are performed using ADCs Cx and Cx+1. Figure 5B The circuit diagram with Rd+1 enabled is shown. With Rd+1 enabled, current (I) flows in the second channel, as shown. Current I can be measured, and the value of Rd+1 is known; therefore, the value of Rtable2 can be calculated using the following relationship:

[0043] Cx = Bx + I * Rcable2

[0044] I = (Cx + 1) / (Rd + 1)

[0045] Rcable2=(Cx–Bx)*(Rd+1) / (Cx+1)

[0046] In operation 606, discharge switch Rd can be enabled (e.g., closed), while Rd+1 is disabled, and voltage measurement is performed. The value of Rable1 can then be calculated, since the value of Rd is known, and the current flowing in channel 1 can be measured.

[0047] In operation 608, the first three operations (602-606) can be repeated for each channel in the BMS, and the individual cable impedances in the channel can be calculated. In operation 610, an impedance table of cable impedances in the BMS can be generated for use during runtime. During runtime, based on the switch configuration, the relevant cable impedance can be retrieved from the impedance table, and the corresponding correction factor can be applied to the voltage measurement to compensate for the voltage drop of the relevant cable impedance. Because the impedance is calculated, changing the discharge configuration does not trigger recalibration, so recalibration is not required when changing to a new discharge configuration. However, if a change in impedance in the voltage measurement is expected (e.g., due to temperature changes), the impedance calculation calibration can be rerun.

[0048] Voltage gain techniques address measurement errors by creating correction factors (e.g., gain factors) based on battery measurements with a desired discharge switch to be activated during operation. These gain factors can then be applied to measurements activated by the discharge switch to compensate for variations introduced during operation. However, because the gain factors depend on the discharge switch configuration, a new set of gain factors is calculated when the discharge switch configuration changes (e.g., a change in the activation of the discharge switch group).

[0049] Figure 7 A flowchart of method 700 for determining voltage gain factor is shown. In operation 702, discharge switches (e.g., Rd, Rd+1) in the voltage system are disabled. In operation 704, a baseline measurement is performed. If the battery pack is in use, the system can wait for the filters (e.g., IIR filters) in the voltage measurement system to stabilize before the baseline measurement is performed, as described in further detail below. In operation 706, a set of discharge switches can be enabled. The enabled set of discharge switches corresponds to the discharge switch configuration used during operation. In operation 708, a discharge enable measurement is performed. In operation 710, a gain table of gain factors for a specific discharge switch configuration can be determined based on the baseline measurement and the discharge enable measurement. For example, the gain factor can be expressed by the following formula:

[0050] Baseline measurement / discharge enabled measurement

[0051] During operation, correction factors (e.g., gain factors) can be applied to voltage measurements to compensate for voltage measurement errors. As described above, a new set of correction factors can be calculated when the discharge switch configuration changes. For example, the system can detect that the discharge switch configuration has changed and can rerun method 700 to calculate a new set of correction factors (e.g., gain tables) based on the new discharge configuration. Furthermore, if a change in impedance is expected in the voltage measurement (e.g., due to temperature variations), the voltage gain calibration can also be rerun. When frequently switching between even and odd discharge switches, the system can generate two gain tables, one for even discharge switches and one for odd discharge switches, to accommodate changes in discharge configurations without recalculating correction factors.

[0052] As mentioned above, the filter properties used in voltage measurements can introduce another source of measurement error. Analog or digital filters can be used. For example, an infinite impulse response (IIR) filter can be used after analog-to-digital conversion.

[0053] The response of an analog or digital filter can be determined, and a scaling factor based on the digital response can be calculated. This scaling factor can then be applied to the measured values, as described in further detail below.

[0054] When using an IIR filter, changes in the discharge switch configuration are not immediately observed; instead, they attenuate according to the IIR step response. To accommodate this rolling IIR step response, a correction factor determined by impedance calculations or voltage gain methods can be scaled based on the sample's position within the IIR transfer function. The scaling factor can be calculated using the implicit form of the IIR transfer function or the explicit form of its step response, or using a lookup table. Using a lookup table saves computation time, as other techniques involve iterative calculations or power functions.

[0055] A running conversion counter (CT) can be used to track the appropriate position in a timely manner. In the case of analog filters, the time value can be maintained by a clock. The number of entries in the lookup table can be scaled according to the desired cell update rate and the desired accuracy of the applied correction factor. If compensated measurements were used in the calibration phase described above, and the IIR filter is in use, the measurements taken during calibration can also be scaled. In the case of the impedance calculation method, the old impedance table can be used for compensation of the current discharge configuration, with appropriate IIR scaling applied. In the case of the voltage gain method, if the discharge configuration has changed, the old gain table may be insufficient to obtain compensation results during calibration. Instead, the system can dynamically update the gain table during the calibration phase. The known IIR step response can be used for this update. With the base measurements and the known step response recorded, the inferred gain factor can be calculated using subsequent measurements.

[0056] Gain=(cal_base-cal_meas+cal_meas*IIR_scale_factor) / (cal_meas*IIR_scale_factor).

[0057] After recording the new gain factor, compensation can be applied to subsequent measurements. This process can be repeated until the filter stabilizes, at which point the gain factor can be calculated normally.

[0058] The transfer function of an IIR filter can be expressed as:

[0059] Y[n]=Y[n–1]+(X[n]–Y[n-1]) / a

[0060] Where X[n] represents the nth input, Y[n] represents the nth output, and a is a programmable filter parameter. To determine the scaling factor, the unit step response of the IIR filter can be rewritten explicitly (the equation does not depend on past outputs) as:

[0061] Ystep[n] = 1 - (1 - 1 / a)^n

[0062] Where Ystep[n] represents the scaling factor when the discharge is activated, a is the programmable filter parameter, and n is the number of samples. Figure 8 A graph showing the scaling of battery voltage and IIR response is presented. As shown, scaling is applied when the switch is disabled in one direction (1-Ystep[n]), and when the switch is enabled.

[0063] When (Ystep[n]) is used, scaling is applied in the other direction.

[0064] To save computation time, a lookup table can be derived from the function described above. The appropriate index in this table can be determined by subtracting the conversion CT value closest to the change in discharge switch configuration (considering CT overflow) from the CT value of the current conversion. Figure 9A A portion of the lookup table for the step response of an IIR filter unit with a CT increment of 1 is shown. Reduced lookup tables can also be used. For example, a simplified table could include incremental CT values ​​at different time intervals (e.g., a step size of 4). Using a reduced table can result in a small step size for the corrected output, but this trade-off can still lead to efficiency when the step size is small compared to uncertainties from other error sources, for example. Figure 9B A portion of a scaled-down lookup table for the step response of an IIR filter unit with a CT increment of 4 is shown.

[0065] Figure 10 A flowchart of a method 1000 for generating a voltage measurement with error compensation is shown. In operation 1002, a calibration cycle can be performed to determine a correction factor to compensate for ohmic losses. For example, the impedance calculation technique or voltage gain technique described above can be performed to determine the correction factor to be used during operation. The determined correction factor can be stored.

[0066] Runtime operations may include acquiring the raw voltage measurement and correcting for measurement errors. In operation 1004, the raw voltage measurement can be recorded. Additionally, filter response attributes and time can be recorded. For example, IIR measurements and CT values ​​can be recorded.

[0067] In operation 1006, the system can check whether a discharge switch configuration change is in progress to determine whether scaling should be performed to address gyration errors. If the discharge switch configuration change is not in progress, in operation 1008, the corresponding correction factor based on the discharge configuration is retrieved from the stored correction factors and applied to the voltage measurement.

[0068] If a discharge switch configuration change is in progress, in operation 1010, the corresponding correction factor based on the discharge configuration is retrieved. In operation 1012, an appropriate scaling factor can be obtained from the unit step response lookup table. In operation 1014, the scaling factor can be used to scale the correction factor, and the scaled correction factor can be applied to the voltage measurement. In operation 1016, the system can then be prepared for the next measurement (e.g., data is ready). In some examples, if the discharge configuration has changed and if the calibration cycle uses the voltage gain technique described above, the calibration cycle can be performed again.

[0069] Figure 11 A battery voltage graph showing the calibrated voltage measurement during continuous measurement is displayed. (Comparison) Figure 11 and Figure 4 The curve. DC offset is eliminated based on the correction factor, and gyration error is eliminated based on the scaling factor mentioned above.

[0070] If the system changes the discharge switch state when the digital filter stabilizes, the index used for IIR scaling of the correction factor can be shifted to reflect the new starting value. This shift can be achieved by locating the index of the currently used correction factor in the table to be used (e.g., 1-table[CT] to table[CT]). This index can then be added to the CT value to scale the correction coefficient appropriately.

[0071] Various annotations

[0072] Each of the above non-limiting aspects may exist independently or may be combined with one or more other aspects or other topics described in this document in various permutations or combinations.

[0073] The above detailed description includes references to the accompanying drawings, which form part of the detailed description. The drawings illustrate, by way of illustration, specific embodiments in which the invention can be practiced. These implementations are generally also referred to as “examples.” Such examples may include elements other than those shown or described. However, the inventors also contemplate examples that provide only those elements shown or described. Furthermore, the inventors also contemplate examples using any combination or arrangement of those elements (or one or more aspects thereof) shown or described, or with respect to a particular example (or one or more aspects thereof), or with respect to other examples (or one or more aspects thereof) shown or described herein.

[0074] If there is any inconsistency between the usage in this document and any other document merged by reference, the usage in this document shall prevail.

[0075] In this document, the terms “a” or “an” are common in patent documents and include one or more, independent of any other instances or uses of “at least one” or “one or more”. Unless otherwise stated, “A or B” includes “A but not B”, “B but not A”, and “A and B”. In this document, the terms “comprising” and “wherein” are used as their plain English equivalents to the respective terms “including” and “comprising”. Furthermore, in the following claims, the terms “comprising” and “including” are open-ended, meaning that systems, devices, articles, compositions, formulations, and methods that include elements other than those listed after the term in a claim are still considered to fall within the scope of that claim. Additionally, in the following claims, the terms “first,” “second,” and “third,” etc., are used merely as labels and are not intended to impose numerical requirements on their objects.

[0076] The methods described herein may be implemented, at least in part, by a machine or computer. Some examples may include computer-readable or machine-readable media encoded with instructions that can be used to configure an electronic device (e.g., a machine, a processor) to perform the methods described in the examples above. Implementations of these methods may include code, such as microcode, assembly language code, high-level language code, etc. This code may include computer-readable instructions for performing various methods. The code may form part of a computer program product. Furthermore, in one example, the code may be tangibly stored on one or more volatile, non-transitory, or non-volatile tangible computer-readable media, for example, during execution or at other times. Examples of such tangible computer-readable media may include, but are not limited to, hard disks, removable disks, removable optical discs (e.g., compact discs and digital video discs), magnetic tape cassettes, memory cards or sticks, random access memory (RAM), read-only memory (ROM), etc.

[0077] The above description is intended to be illustrative and not restrictive. For example, the examples (or one or more aspects thereof) described above may be used in combination with each other. Other implementations may be used, for example, by those skilled in the art upon review of the above description. An abstract is provided to allow the reader to quickly determine the nature of the technical disclosure. It should be understood that this document is not intended to interpret or limit the scope or meaning of the claims. Furthermore, in the detailed description above, various features may be grouped together to simplify this disclosure. This should not be construed as meaning that unclaimed features of the disclosure are essential to any claim. Rather, the subject matter of the invention may not be limited to all features of an implementation of a particular disclosure. Therefore, the following claims are incorporated herein as examples or implementations, wherein each claim is an independent, separate implementation, and these implementations are contemplated to be combined with each other in various combinations or arrangements. The scope of the invention should be determined by reference to the appended claims and the full scope of their equivalents.

Claims

1. A method for compensating for measurement errors in a battery pack management system, the method comprising: A calibration cycle is performed to calculate a set of correction factors, wherein the set of correction factors is calculated based on the determined cable impedance of each channel in the battery pack management system, the calibration cycle including: Disable one or more discharge switches in the channels of the battery management system. The first measurement is performed based on one or more discharge switches in the disabled channel. Activate the first discharge switch among the one or more discharge switches in the battery management system. The second measurement is performed based on activating the first discharge switch among the one or more discharge switches. Activate the second discharge switch among the one or more discharge switches in the battery management system. The third measurement is performed based on activating the second discharge switch among the one or more discharge switches, and At least one cable impedance is determined based on the first measurement, the second measurement, and the third measurement; Receive raw voltage measurements; and At least one correction factor from the set of correction factors is applied to produce a compensated voltage measurement.

2. The method according to claim 1, further comprising: It was determined that the original voltage measurement was being received during the discharge switch configuration change; Obtain a scaling factor related to the filter characteristics used to generate the original voltage measurement; and The at least one correction factor is scaled using the scaling factor.

3. A battery pack management system, comprising: At least one hardware processor; and At least one memory storing instructions, wherein when the at least one hardware processor executes the instructions, the instructions cause the at least one hardware processor to perform an operation, the operation including: A calibration cycle is performed to calculate a set of correction factors, wherein the set of correction factors is calculated based on the determined cable impedance of each channel in the battery pack management system, the calibration cycle including: Disable one or more discharge switches in the channels of the battery management system. The first measurement is performed based on one or more discharge switches in the disabled channel. Activate the first discharge switch among the one or more discharge switches in the battery management system. The second measurement is performed based on activating the first discharge switch among the one or more discharge switches. Activate the second discharge switch among the one or more discharge switches in the battery management system. The third measurement is performed based on activating the second discharge switch among the one or more discharge switches, and At least one cable impedance is determined based on the first measurement, the second measurement, and the third measurement; Receive raw voltage measurements; and At least one correction factor from the set of correction factors is applied to produce a compensated voltage measurement.

4. The battery pack management system according to claim 3, further comprising: It was determined that the original voltage measurement was being received during the discharge switch configuration change; Obtain a scaling factor related to the filter characteristics used to generate the original voltage measurement; and The at least one correction factor is scaled using the scaling factor.

5. A machine-readable medium containing instructions that, when executed by a machine, cause the machine to perform operations, the operations including: A calibration cycle is performed to calculate a set of correction factors, wherein the set of correction factors is calculated based on the determined cable impedance of each channel in the battery pack management system, the calibration cycle including: Disable one or more discharge switches in the channels of the battery management system. The first measurement is performed based on one or more discharge switches in the disabled channel. Activate the first discharge switch among the one or more discharge switches in the battery management system. The second measurement is performed based on activating the first discharge switch among the one or more discharge switches. Activate the second discharge switch among the one or more discharge switches in the battery management system. The third measurement is performed based on activating the second discharge switch among the one or more discharge switches, and At least one cable impedance is determined based on the first measurement, the second measurement, and the third measurement; Receive raw voltage measurements; and At least one correction factor from the set of correction factors is applied to produce a compensated voltage measurement.

6. The machine-readable medium of claim 5, further comprising: It was determined that the original voltage measurement was being received during the discharge switch configuration change; Obtain a scaling factor related to the filter characteristics used to generate the original voltage measurement; and The at least one correction factor is scaled using the scaling factor.

7. A method for compensating for measurement errors in a battery pack management system, the method comprising: Perform a calibration cycle to calculate a set of correction factors, wherein the set of correction factors is calculated based on voltage gain values, the calibration cycle including: Disable one or more discharge switches in the battery management system. The first measurement is performed based on disabling one or more of the discharge switches. Enable one or more discharge switches in the battery management system that are associated with the discharge switch configuration. The second measurement is performed based on activating one or more discharge switches associated with the discharge switch configuration, and The voltage gain value associated with the discharge switch configuration is determined based on the first and second measurements; Receive raw voltage measurements; and At least one correction factor from the set of correction factors is applied to produce a compensated voltage measurement.

8. The method of claim 7, further comprising: Determine the change in the configuration of the discharge switch, and The calibration cycle is performed using the modified discharge switch configuration to determine the voltage gain value associated with the modified discharge switch configuration.

9. A battery pack management system, comprising: At least one hardware processor; and At least one memory storing instructions, wherein when the at least one hardware processor executes the instructions, the instructions cause the at least one hardware processor to perform an operation, the operation including: Perform a calibration cycle to calculate a set of correction factors, wherein the set of correction factors is calculated based on voltage gain values, the calibration cycle including: Disable one or more discharge switches in the battery management system. The first measurement is performed based on disabling one or more of the discharge switches. Enable one or more discharge switches in the battery management system that are associated with the discharge switch configuration. The second measurement is performed based on activating one or more discharge switches associated with the discharge switch configuration, and The voltage gain value associated with the discharge switch configuration is determined based on the first and second measurements; Receive raw voltage measurements; and At least one correction factor from the set of correction factors is applied to produce a compensated voltage measurement.

10. The battery pack management system according to claim 9, further comprising: Determine the change in the configuration of the discharge switch, and The calibration cycle is performed using the modified discharge switch configuration to determine the voltage gain value associated with the modified discharge switch configuration.

11. A machine-readable medium containing instructions that, when executed by a machine, cause the machine to perform operations, the operations including: Perform a calibration cycle to calculate a set of correction factors, wherein the set of correction factors is calculated based on voltage gain values, the calibration cycle including: Disable one or more discharge switches in the battery management system. The first measurement is performed based on disabling one or more of the discharge switches. Enable one or more discharge switches in the battery management system that are associated with the discharge switch configuration. The second measurement is performed based on activating one or more discharge switches associated with the discharge switch configuration, and The voltage gain value associated with the discharge switch configuration is determined based on the first measurement and the second measurement; Receive raw voltage measurements; and At least one correction factor from the set of correction factors is applied to produce a compensated voltage measurement.

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