Claims:We claim:

1. A method for estimating state of health (SoH) of batteries (1001, 1002, 1003) in electric vehicles, comprising:
determining, by a battery management system (BMS) (201), pack parameters of one or more cells (1011, 1012, 1013) in a battery (1001 or1002 or 1003) of an electric vehicle during plug-in cycles, wherein the electric vehicle is stationary during plug-in cycles, wherein one or more charging profiles are applied to the one or more cells (1011, 1012, 1013) in the battery (1001 or 1002 or 1003);
determining, by the BMS (201), pack parameters of the one or more cells (1011, 1012, 1013) during driving cycles, wherein the electric vehicle is in motion during the driving cycles; and
providing, by the BMS (201), the pack parameters of the one or more cells (1011, 1012, 1013) determined during the plug-in cycles and the driving cycles to a remote server (204) for estimating the SoH of the one or more cells (1011, 1012, 1013),
wherein the estimated SoH is used for determining maintenance operation or battery replacement and used for internal calculations such as state of charge (1001 or 1012 or 1013).

2. The method as claimed in claim 1, wherein determining the pack parameters of the one or more cells (1011, 1012, 1013) comprises determining state of charge (SoC), pack/battery current values, cell voltage values and temperature values.

3. The method as claimed in claim 2, wherein the SoC indicates a ratio of total charge stored in the one or more cells (1011, 1012, 1013) with respect to its capacity.

4. The method as claimed in claim 1, wherein determining the pack parameters during plug-in cycles comprises:
applying the one or more charging profiles to the one or more cells (1011, 1012, 1013) while the one or more cells (1011, 1012, 1013) are charged while the electric vehicle is stationary; and
measuring pack/battery current values, cell voltage values and temperature values of the one or more cells (1011, 1012, 1013) for each charging profiled applied.

5. The method as claimed in claim 1, wherein one or more charging profiles comprises different current profiles or voltage profiles or electrical load.

6. The method as claimed in claim 1, wherein determining the SoC during driving cycles comprises:
determining pack/battery current values, cell voltage values and temperature values of the one or more cells (1011, 1012, 1013) when the one or more batteries are discharged and charged (regen) while the electric vehicle is in motion.

7. The method as claimed in claim 1, wherein the pack parameters of the one or more cells (1011, 1012, 1013) determined during the plug-in cycles and the driving cycles are used to determine charge capacity and increase in resistance to charge in the one or more cells (1011, 1012, 1013).

8. The method as claimed in claim 1, wherein the SoH is estimated further using historical data of SoC of the one or more cells (1011, 1012, 1013), cell voltage values, pack/battery current value and temperature value of the one or more cells (1011, 1012, 1013).

9. A battery management system (BMS) (201) for estimating state of health (SoH) of batteries (1001, 1012, 1013) in electric vehicles, comprising:
a processor; and
a memory, communicatively coupled to the processor, wherein the processor is configured to:
determine pack parameters of one or more cells (1011, 1012, 1013) in a battery (1001 or 1012 or 1013) of an electric vehicle during plug-in cycles, wherein the electric vehicle is stationary during plug-in cycles, wherein one or more charging profiles are applied to the one or more cells (1011, 1012, 1013) in the battery (1001 or1012 or 1013);
determine SoC of the one or more cells (1011, 1012, 1013) during driving cycles, wherein the electric vehicle is in motion during the driving cycles; and
provide the SoC of the one or more cells (1011, 1012, 1013) determined during the plug-in cycles and the driving cycles to a remote server (204) for estimating the SoH of the one or more cells (1011, 1012, 1013),
wherein the estimated SoH is used for determining maintenance operation or battery replacement and used for internal calculations such as state of charge (1001 or1012 or 1013).

10. The BMS (201) as claimed in claim 9, wherein processor determines the SoC of the one or more cells (1011, 1012, 1013) by determining pack/battery current values, cell voltage values and temperature values of the one or more batteries (1001, 1002, 1003).

11. The BMS (204) as claimed in claim 9, wherein processor determines the pack parameters during plug-in cycles by:
applying the one or more charging profiles to the one or more cells (1011, 1012, 1013) while the one or more cells (1011, 1012, 1013) are charged while the electric vehicle is stationary; and
measuring pack/battery current values, cell voltage values and temperature values of the one or more cells (1011, 1012, 1013) for each charging profiled applied.

12. The BMS (201) as claimed in claim 9, wherein the processor determines the SoC during driving cycles by:
determining pack/battery current values, cell voltage values and temperature values of the one or more cells (1011, 1012, 1013) when the one or more batteries (1001, 1002, 1003) are discharged and charged (regen) while the electric vehicle is in motion.

13. The BMS as claimed in claim 9, wherein the remote server (204) determines the pack parameters of the one or more cells during the plug-in cycles and the driving cycles for determining charge capacity and increase in resistance to charge in the one or more cells (1011, 1012, 1013).

14. The BMS as claimed in claim 9, wherein the remote server (204) estimates the SoH further using historical data of SoC of the one or more cells (1011, 1012, 1013), cell voltage value, pack/battery current value and temperature value of the one or more cells (1011, 1012, 1013).

Dated this March 27th, 2019

GOPINATH. A. S.
OF K&S PARTNERS
AGENT FOR THE APPLICANT(S)
IN/PA-1852
, Description:FORM 2
THE PATENTS ACT 1970
[39 OF 1970]
&
THE PATENTS RULES, 2003

COMPLETE SPECIFICATION
[See section 10 and Rule 13]

TITLE: “METHOD OF ESTIMATING STATE OF HEALTH OF BATTERIES IN ELECTRIC VEHICLE AND SYSTEM THEREOF”

Name and Address of the Applicant:
Applicant 1: TATA MOTORS LIMITED
Applicant 2: TATA MOTORS EUROPEAN TECHNICAL CENTRE PLC

Nationality: India and United Kingdom

The following specification particularly describes the invention and the manner in which it is to be performed.

TECHNICAL FIELD
[001] The present disclosure relates to electric vehicles. More particularly, the present invention relates to estimating State of Health (SoH) of batteries in electric vehicles.

BACKGROUND
[002] Currently, in the automotive industry, electric vehicles (EVs) are being adopted more widely. EVs use high capacity batteries to provide long range. EVs may have a single battery or a plurality of batteries depending on EV model type and application. For example, a commercial EV may require a plurality of batteries whereas passenger EVs may require one battery or a couple of batteries. A battery pack is typically a collection of batteries with a battery (also called a module) being a series of connected cells. Connected cells refers to a single or a number of parallel connected cells.
The batteries have to be regularly charged. Typically, for a passenger hatchback EV, a completely charged battery can provide a range of 200-350kms at ambient temperature and normal road conditions. Depending on terrain and weather conditions the EV has commuted, range and charging patterns can vary.

[003] Various parameters are considered to determine performance of the battery including state of charge (SoC) which indicates the ratio of the charge present in the battery to total battery charge capacity (at that time or with respect to nominal reference value); and state of health (SoH) which indicates the condition of the battery. As generally known, the capacity of the cells reduces with increased age of the cells and likewise resistance to flow of charge increases. Typically, reduction in capacity of the cells limits the EV range and increase in resistance affects EV power delivery.

[004] The estimates of decrease in capacity and increase in resistance can be fed back to the EV driver or service team to provide vital information about the health of the battery pack. The driver is informed of the SoC of the pack based on individual cells SoC. Estimating SoC accurately requires that the capacity of the cells is known. Additionally, capacity and resistance estimates may be used in the future. Further, SoH can be used to determine that a service is required, or batteries need replacing.

[005] Generally, during production of batteries, tests are performed to determine cell characteristics. Typically, the tests are performed by providing different values of current and voltage by connecting different load to the cells. The characteristics of the cells are measured for each input current and voltage for a particular value of load connected to the cells.

[006] Existing systems estimate SoC and SoH by taking measurements of current, voltage and temperatures (at specific points and also including from the cooling system and ambient sensors) while the EV is in stationary and is in mobile state. Also, the existing systems obtain the measurements at arbitrary cycles and estimate the SoH. SoH estimation means that existing systems do not measure SoH directly and not necessarily accurately. Also, performing the tests for determining cell characteristics of cells as mentioned above is not feasible in an EV, as EV may require high memory capabilities which is cost prohibitive in a production car and as the test can extend or long durations. As a result, current technologies fail to provide accurate, noise-free approach of estimating SoH.

[007] The information disclosed in this background of the disclosure section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

SUMMARY
[008] In an embodiment, a method is proposed for estimating State of Health (SoH) of batteries in an electric vehicles (EV). The method comprises determining a state of charge (SoC) of one or more cells in a battery of the EV during a plug-in cycle. In an embodiment, plug-in cycles refer to cycles during which the EV is plugged-in to a charger and the EV is stationary. In an embodiment, during plug-in cycles, one or more charging profiles can be applied to the cells in a battery. Further, the method comprises determining SoC of the one or more cells during driving cycles. In an embodiment, during driving cycles, the EV is in motion. Thereafter, the method comprises providing the SoC of the one or more cells determined during the plug-in cycles and the driving cycles to a remote server for estimating state of health (SoH) of the one or more cells. In an embodiment, the remote server is configured to determine the SoH (life of the battery) based on the SoC and historical data about the one or more cells. The estimated SoH may be used as a maintenance indication to driver of the EV and also used in the BMS to improve SOC estimation accuracy.

[009] In an embodiment, a method is proposed for estimating State of Health (SoH) of batteries in an electric vehicles (EV). The method comprises determining a state of charge (SoC) of one or more cells in a battery of the EV during plug-in cycle. In an embodiment, plug-in cycles refer to cycles during which the EV is plugged-in to a charger and the EV is stationary. In an embodiment, during plug-in cycles, one or more charging profiles can be applied to the one or more cells. Further, the method comprises determining SoC of the one or more cells during driving cycles. In an embodiment, during driving cycles, the EV is in motion. Thereafter, the method comprises providing the SoC of the one or more cells determined during the plug-in cycles and the driving cycles to a remote server for estimating state of health (SoH) of the one or more cells. In an embodiment, the remote server is configured to determine the SoH (life of the battery) based on the SoC and historical data about the one or more cells. The estimated SoH may be used as a maintenance indication to driver of the EV.

[0010] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0011] The novel features and characteristic of the disclosure are set forth in the appended claims. The disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:

[0012] Figure 1A shows a diagram of a battery pack, in accordance with an embodiment of the present disclosure;

[0013] Figure 1B is illustrative of cells in parallel combination inside a battery in accordance with an embodiment of the present disclosure;

[0014] Figure 1C is illustrative of a cell in a battery in accordance with an embodiment of the present disclosure;

[0015] Figure 2 shows an exemplary block diagram illustrating estimation of SoH of cells in an EV battery, in accordance with an embodiment of the present disclosure;

[0016] Figure 3 shows an exemplary flow chart illustrating steps for estimating SoH of cells in an EV battery, in accordance with an embodiment of the present disclosure;

[0017] Figure 4 shows an exemplary flow chart illustrating steps for estimating SoC of cells during plug-in cycles, in accordance with an embodiment of the present disclosure; and

[0018] Figure 5 shows an exemplary flow chart illustrating steps for estimating SoC of cells during driving cycles, in accordance with an embodiment of the present disclosure.

[0019] It should be appreciated by those skilled in the art that any block diagrams herein represent conceptual views of illustrative systems embodying the principles of the present subject matter. Similarly, it will be appreciated that any flow charts, flow diagrams, state transition diagrams, pseudo code, and the like represent various processes that may be substantially represented in computer readable medium and executed by a computer or processor, whether or not such computer or processor is explicitly shown.

DETAILED DESCRIPTION
[0020] In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

[0021] While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.

[0022] The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, device or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a system or apparatus proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus.

[0023] Embodiments of the present disclosure relate to a method and system for estimating state of health (SoH) of batteries in electric vehicles (EVs). The system determines state of charge (SoC) of one or more cells of the battery during plug-in cycles and driving cycles. During plug-in cycles, the EVs are stationary and charged using a charger. The charger can be configured to apply one or more charging profiles during the plug-in cycles. Each charging profile can apply different current values or voltage values. In an embodiment, different load can be applied at different current values and voltage values. The different load can affect the voltage values and current values. For each charging profile, cell voltage, current and temperatures are monitored. Likewise, during driving cycles cell voltage and current and temperatures are monitored. The monitoring during plug-in cycles and driving cycles are used to estimate SoH of the cells. In an embodiment, the temperatures can be measured at specific points and also including from the cooling system and ambient sensors. The estimated SoH is then used as an indicator for scheduling maintenance activities or for replacing the battery and for internal calculations such as state of charge.

[0024] Figure 1A shows a schematic of a plurality of batteries (1001, 1002, 1003) connected in series. The plurality of batteries (1001, 1002, 1003) are interchangeably referred as a battery pack (100) in the present disclosure. In an embodiment, an individual battery may be referenced by (100n, wherein n=1, 2, 3…). The battery pack (100) can provide a combined effect of individual batteries (1001, 1002, 1003). In an embodiment, as shown, positive terminal of battery (100¬1) is connected to negative terminal of battery (100¬2). Likewise, the batteries (1001, 1002, 1003) are connected to form the battery pack (100). The free terminals of battery (1001 & 1003) are connected to the EV. In an embodiment, the plurality of batteries (1001, 1002, 1003) can be individually used to provide the same effect of the battery pack (100).

[0025] Figure 1B is illustrative of cells (101) in series combination inside a battery in accordance with an embodiment of the present disclosure. In one embodiment, a battery (1001) can comprise a plurality of cells (1011, 1012, 1013). Each of these can be a number of parallel cells. For example, a battery pack may comprise 10 batteries. Each battery comprises 12 series sets of 2 cells in parallel. Such a pack is often referred to as 120S2P. In an exemplary embodiment, the battery (1001) can be a lithium-ion battery. In another embodiment, the battery (1001) can have any other chemical composition that works on the principle similar/ same as lithium-ion battery. In another embodiment, a battery (e.g., 1001) can comprise only one cell (e.g., 1011) as shown in Figure 1C. In a first example, a commercial EV can comprise a battery pack (100), each battery (1001, 1002, 1003) comprising a plurality of cells (1011, 1012, 1013). In a second example, a passenger EV can comprises a single battery (e.g., 1001) comprising either plurality of cells (1011, 1012, 1013) or a single cell (1011). Depending on required range, EV type, road conditions, and weather conditions, the EV can be configured with predefined number of batteries (1001, 1002, 1003). Specifically, number of parallel and series cells are chosen to give the desired energy (e.g., range) and power for the EV.

[0026] Figure 2 shows an exemplary block diagram illustrating estimation of SoH of cells in an EV battery, in accordance with an embodiment of the present disclosure. The EV comprises a plurality of components including a battery management system (BMS) (201), and an electronic control unit (ECU) (202). The BMS (201) is typically configured to determine behaviour of battery/ battery pack (100). The determined behaviour is provided to the driver or service team or used internally in the BMS. Generally, the BMS (201) is configured to monitor voltage, current, temperature, SoC, SoH of the battery pack (100). Also, the BMS (201) is configured to balance voltage of the cells (1011, 1012, 1013), and isolate the cells (1011, 1012, 1013) under abnormal conditions, charge the cells (1011, 1012, 1013) and the like.

[0027] In an embodiment, the BMS (201) is connected to the ECU (202) via a communication bus, for example a control area network (CAN) bus. The BMS (201) may provide indications such as, but not limited to, SoC indications, service indications, battery replacement indications, temperature indications, and the like. The ECU (202) may configure an instrument panel of the EV to display the indications.

[0028] In an embodiment, the BMS (201) is configured to measure at least temperature values and, cell voltage and pack/battery current values (1011, 1012, 1013) of the battery (1001). In one embodiment, the cells (1011, 1012, 1013) can be charged by a charger. In one embodiment, the charger can be configured in the EV or can be stationed at a charging station. In an embodiment, the charger can comprise a rectifier to convert AC to DC for charging the cells (1011, 1012, 1013). In an example embodiment, the voltage in the battery (1001) may vary from 48VDC to over 400VDC.

[0029] In an embodiment, the BMS (201) may be connected to a remote server (204). The remote server (204) may be configured to estimate SoH using the measurements received from the BMS (201). The remote server (204) may also use historical measurements of the cells (1011, 1012, 1013) for estimating the SoH. In an embodiment, the BMS (201) may be configured to send every measurement of the cells (1011, 1012, 1013) to the remote server (204). In one embodiment, the BMS (201) can send the measurements periodically (for example once a week). In another embodiment, the BMS (201) can send the measurements during service/ maintenance. In an embodiment, the remote server may use any existing techniques to estimate the SoH of the cells (1011, 1012, 1013). For example, coulomb counting method, voltage method or Kalman filter method can be employed to estimate SoC and SoH.

[0030] In an embodiment, the BMS (201) may communicate with the remote server (204) via a network interface (203). The network interface (203) may employ connection protocols including, without limitation, direct connect, Ethernet (e.g., twisted pair 10/100/1000 Base T), transmission control protocol/Internet protocol (TCP/IP), token ring, IEEE 802.11a/b/g/n/x, etc. The network interface (203) may include, without limitation, a direct interconnection, wired connection, e-commerce network, a peer to peer (P2P) network, Local Area Network (LAN), Wide Area Network (WAN), wireless network (e.g., using Wireless Application Protocol (WAP)), the Internet, Wireless Fidelity (Wi-Fi), etc.

[0031] Figure 3 shows a flow chart illustrating a method for estimating SoH of cells (1011, 1012, 1013) in a battery (1001), in accordance with some embodiments of the present disclosure.

[0032] As illustrated in Figure 3, the method 300 may comprise one or more steps. The method 300 may be described in the general context of processor executable instructions. Generally, processor executable instructions can include routines, programs, objects, components, data structures, procedures, modules, and functions, which perform particular functions or implement particular abstract data types.

[0033] The order in which the method 300 is described is not intended to be construed as a limitation, and any number of the described method blocks can be combined in any order to implement the method. Additionally, individual blocks may be deleted from the methods without departing from the scope of the subject matter described herein. Furthermore, the method can be implemented in any suitable hardware, software, firmware, or combination thereof.

[0034] At step 301, the BMS (201) determines the SoC of the one or more cells (1011, 1012, 1013) during plug-in cycles. In an embodiment, during plug-in cycles (i.e., when the EV is connected to a charger) the EV is stationary. In one embodiment, the charger may be configured to apply different charging profiles to the cells (1011, 1012, 1013). Now referring to Figure 4, at step 401, the charger may be capable of applying different charging profiles. In another embodiment, a device (e.g., pulse width modulator (PWM), current generator, a clamper circuit and the like) associated with the charger can be used to apply the charging profiles. In an embodiment, the charging profiles comprises at least current values (or voltage values or prescribed loads). For example, a first charging profile can comprise 400V and 15A. A second charging profile can comprise 600V and 15A. The charger or suitable device may apply first charging profile to the cells (1011, 1012, 1013).

[0035] At step 402, the BMS (201) is configured to measure the output characteristics of the cells (1011, 1012, 1013). The output characteristics/ pack parameters can comprise cell voltage, cell current, temperatures, estimated SoC. Likewise, the output characteristics/ pack parameters of the cells (1011, 1012, 1013) are measured when the second charging profile is applied. In an embodiment, the term “output characteristics” and the term “pack parameters” are used interchangeably in the present disclosure. In an embodiment, constant voltage or current may also be applied and output characteristics of the cells (1011, 1012, 1013) are measured.

[0036] In an embodiment, varied pulse width may also be applied to the cells (1011, 1012, 1013) and the output characteristics are measured. The cell voltage and current can be used for determining the SoC of the cells (1011, 1012, 1013) during the plug-in cycles. In an embodiment, the cells (1011, 1012, 1013) can be charged using standard techniques including, but is not limited to, national electric code, SAE J2293, SAE J2836, SAE J1772, IEC 62196 and IEEE 1547.3.

[0037] Referring back to Figure 3, at step 302, the BMS (201) is configured to determine SoC of the cells (1011, 1012, 1013) during the driving cycles. During driving cycles, the EV is in motion. Reference is now made to Figure 5. Step 501 is performed by the BMS (201) when an on-board generator is present in the EV. In an embodiment, the on-board generator may be capable of charging the cells (1011, 1012, 1013) when the EV is in motion. If the EV does not comprise the on-board generator, the step 502 is performed.

[0038] At step 501, the different charging profiles are applied to the cells (1011, 1012, 1013) when an on-board generator is present in the EV. The on-board generator may be capable of applying the charging profiles to the cells (1011, 1012, 1013) while the EV is in motion.

[0039] At step 502, the BMS (201) is configured to measure the output characteristics comprising the pack/battery current values, cell voltage values and temperature values. In one embodiment, the measurement may be made for each charging profile applied. In absence of the on-board generator, the measurement may be made while the cells (1011, 1012, 1013) discharge. The measurements are used to estimate SoC of the cells (1011, 1012, 1013) during the driving cycles.

[0040] In an embodiment, using the one or more charging profiles help in mimicking battery characterization tests. Hence, the characteristics of batteries are estimated accurately, thereby providing accurate battery indications such as battery replacement and SoC. Also, maintenance/ replacement of the battery can be scheduled timely resulting in maintaining performance of the EV.

[0041] Referring back to Figure 3, at step 303, the measurements made during the plug-in cycles and during the driving cycles are provided to the remote server (204) for estimating the SoH. In an embodiment, the remote server (204) may use existing techniques to estimate the SoH. For example, models like electrochemical models and equivalent circuit models can be used for estimating SoH. In one embodiment, an onboard computer may be capable of estimating the SoH.

[0042] In an embodiment, the BMS (201) is configured to receive the SoH from the remote server (204)/ onboard computer and provide indication on the instrument panel about scheduling maintenance or indication for replacing the battery (1011) or use the value for internal calculations such as state of charge.

[0043] In an embodiment, the SoH can be used by the BMS (201) in the cell balancing strategy. Cell balancing is an essential function of BMS (201), especially for Li-ion batteries. To supply required voltages, cells (1011, 1012, 1013) must be connected in series. During charge and discharge, each cell in a string (cells in the battery) when subjected to same current, can have different SoCs due to several factors, for example, due to cells (1011, 1012, 1013) have different capacities. Even if the manufacturer makes the best effort to match capacities for new cells (1011, 1012, 1013), nonuniform operating conditions impose different thermal and electrical stress on cells (1011, 1012, 1013), causing changes in capacities. Although the cells (1011, 1012, 1013) have small self-discharge, small differences can accumulate over time, causing different SoCs even for cells (1011, 1012, 1013) with nearly identical capacities. Furthermore, variations in internal impedance and material aging can lead to nonuniform cell characteristics. To protect the cells (1011, 1012, 1013) from overheat, overcharge, and over-discharge, the operation of the string is fundamentally limited by the weakest cell, the one reaches SoC upper and lower boundaries first. Such an imbalance prevents battery packs supplying their capacities completely, and consequently limits the battery run time. Cell balancing aims to reduce SoC imbalances within a string by for example, controlling the SoCs of the cells so that they become approximately equal.

[0044] In an embodiment, the proposed method and system provides improved SoC estimation thereby providing better range prediction for the EV. In an embodiment, accurate estimation of SoH can be used to timely indicate maintenance operation or battery replacement and used for internal calculations such as state of charge.

[0045] The terms "an embodiment", "embodiment", "embodiments", "the embodiment", "the embodiments", "one or more embodiments", "some embodiments", and "one embodiment" mean "one or more (but not all) embodiments of the invention(s)" unless expressly specified otherwise.

[0046] The terms "including", "comprising", “having” and variations thereof mean "including but not limited to", unless expressly specified otherwise.

[0047] The enumerated listing of items does not imply that any or all of the items are mutually exclusive, unless expressly specified otherwise. The terms "a", "an" and "the" mean "one or more", unless expressly specified otherwise.

[0048] A description of an embodiment with several components in communication with each other does not imply that all such components are required. On the contrary a variety of optional components are described to illustrate the wide variety of possible embodiments of the invention.

[0049] When a single device or article is described herein, it will be readily apparent that more than one device/article (whether or not they cooperate) may be used in place of a single device/article. Similarly, where more than one device or article is described herein (whether or not they cooperate), it will be readily apparent that a single device/article may be used in place of the more than one device or article or a different number of devices/articles may be used instead of the shown number of devices or programs. The functionality and/or the features of a device may be alternatively embodied by one or more other devices which are not explicitly described as having such functionality/features. Thus, other embodiments of the invention need not include the device itself.

[0050] The illustrated operations of Figure 3, Figure 4, Figure 5, show certain events occurring in a certain order. In alternative embodiments, certain operations may be performed in a different order, modified or removed. Moreover, steps may be added to the above described logic and still conform to the described embodiments. Further, operations described herein may occur sequentially or certain operations may be processed in parallel. Yet further, operations may be performed by a single processing unit or by distributed processing units.

[0051] Finally, the language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the invention be limited not by this detailed description, but rather by any claims that issue on an application based here on. Accordingly, the disclosure of the embodiments of the invention is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.

[0052] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

REFERRAL NUMERALS:
Reference number Description
100 Battery pack
1001, 1002, 1003 Battery
1011, 1012, 1013 Cells
201 Battery Management System (BMS)
202 Electronic Control Unit (ECU)