WO2020227836A1

WO2020227836A1 - Electrical energy storage system, device and method

Info

Publication number: WO2020227836A1
Application number: PCT/CA2020/050660
Authority: WO
Inventors: Maxime VIDRICAIRE; Jonathon DOS SANTOS
Original assignee: Stromcore Energy Inc.
Priority date: 2019-05-15
Filing date: 2020-05-15
Publication date: 2020-11-19
Also published as: CA3081042C; GB2595417A; GB202112382D0; CA3081042A1; EP3966886A4; EP3966886A1

Abstract

A distributed battery module thermal management system, device and method for use in battery pack systems consisting of a plurality of multiple battery modules interconnected in series or parallel. One example of system is for forklift batteries operating in sub-zero applications. The system includes a battery pack master controller that manages each battery module thermally to optimize the cell temperatures. By doing so the system longevity and performance can be maximized. The system consists of a battery monitoring module that collects data from sensors such as thermistors, a housing designed for passive cooling with heaters to provide active heating applied to a module core consisting a plurality of cell blocks.

Description

TITLE: Electrical Energy Storage system, device and method

FIELD OF THE INVENTION

[0001] This invention relates to an electrical energy storage device, system and method, and particularly relates to an NMC battery with modules containing energy storage cells wherein said modules have modular heating for maintaining the modules internal energy cell temperature in a selected temperature range in sub-zero applications.

BACKGROUND OF THE INVENTION

[0002] Individual energy cells are frequently combined together to form packs or modules, either to increase the voltage output of the pack by combining cells in series or to increase current by combining cells in parallel. Over time and many charging and discharging cycles the energy capacity of any single energy cell diminishes, and at different rates for the cells in the module.

[0003] Generally speaking, the performance of a module becomes limited to the performance of the weakest cell. There may also be safety issues with over charging or over discharging any individual cell which means that once a single battery cell has been exhausted, the whole module is unusable, even though some energy cells may still have some useable capacity. Similarly, when a single energy cell has reached full charge, the supply of charge current should be stopped to the whole module to avoid over-charging, even though some cells may not yet be fully charged. Prior art devices have attempted to address this issue.

[0004] For example US 10,291,037 relates to an electrical energy storage device comprising: a plurality of energy cell slots for receiving energy cells; and an individual controller for each energy cell slot of the plurality of energy cell slots; wherein each controller is arranged to estimate a characteristic of a cell in its respective energy cell slot; and wherein each controller is arranged to apply charge and discharge currents to its respective energy cell slot dependent upon at least one estimated characteristic currently associated with that slot.

[0005] However US 10,291,037 relates to cell 'slots' that decide whether to allow current to charge/discharge to particular cells. In the invention to be described herein the modules do not themselves make decisions on whether to allow current to flow. The modules to be described herein simply relay the information to a master controller that then decides whether to activate the module or not, by closing the module relay. [0006] Furthermore US 10,290,909 relates to a battery module including two or more battery cells, which can be charged and discharged, arranged in a stacked state and cartridges for fixing the battery cells to constitute a battery cell stack, wherein each of the cartridges includes a pair of assembly type frames, which are coupled to each other in a state in which a corresponding one of the battery cells is mounted in the frames, at least one of the cartridges includes a temperature sensor mounting unit, and a temperature sensor, mounted in the temperature sensor mounting unit, is configured to have a structure in which ends of a surface of the temperature sensor contacting a corresponding one of the battery cells are round.

[0007] However module design of 10.290,909 highlights the serviceability of the contained cells. The designs centres around 'pouch' cells, whereas the invention to be described herein relates to 'aluminum hard-cased' cells.

[0008] Moreover the capacity of energy cells generally diminish when the battery pack is operated in cold or sub-zero environments such as battery operated lift trucks in a large freezer structure. There is a need for an improved energy storage device, system and method.

SUMMARY OF THE INVENTION

[0009] It is an aspect of this invention to provide an electrical energy storage device comprising: a plurality of spaced energy cells; spaced holders for holding said plurality of spaced energy cell there between; at least one heater associated with at least one of said holders for heating said spaced energy cells at a selected temperature range; sensors for sensing one of the temperature or power capacity of said spaced energy cells; and a controller for controlling said heater to heat said spaced energy cells to said selected temperature range.

[0010] In one embodiment the controller deactivates any energy module that falls below a selected power capacity.

[0011] In another embodiment, the heater is comprised of silicone rubber encasing a resistive wire. The spaced holders can comprise extruded aluminum.

[0012] In yet another embodiment the spaced holders comprise a top holder and bottom holder for holding said spaced plurality of energy cells there between in a module.

[0013] Furthermore the heater is disposed between one of said top and bottom holders, and said plurality of energy cells. The energy cells comprise an NMC battery. [0014] Furthermore in another embodiment the plurality of energy cells are disposed in pairs, where each said pairs of energy cells include a voltage sensor, and where each said module includes a plurality of temperature sensors.

[0015] In yet another embodiment the electrical energy storage device has a module comprises one of;

(a) a 36 volt module and has 3 temperature sensors; or

(b) a 48 volt module and has 4 temperature sensors.

In another embodiment, a relay is disposed in an end cap of said module. Furthermore, each said energy storage device could include a top and bottom cell holder.

[0016] Another aspect of this invention relates to a modular heating system for energy storage devices comprising: a plurality of energy cells in spaced adjacent configuration; spaced aluminum holders for holding said plurality of spaced energy cells between said opposite aluminum holders to define a module; a heater disposed between at least one of said aluminum holders and said plurality of energy cells; a sensor adjacent each pair of said plurality of energy cells to sense the temperature and/or power capacity of said pair of said plurality of said energy cells; a controller connected to each sensor adjacent each pair of said plurality of energy cells for receiving signals from said sensors to control the temperature and/or energy capacity of each pair of said plurality of said energy cells.

[0017] In yet another embodiment the heater comprises: a single top heater is disposed along the entire length of a top extrusion between said top aluminum holder and said plurality of energy cells; and; a single bottom heater disposed along the entire length of a bottom aluminum holder and said plurality of energy cells.

[0018] A further aspect of this invention relates to a method for energy storage for sub-zero applications comprising: placing a plurality of energy cells in spaced adjacent configuration; holding said plurality of spaced energy cells between opposite aluminum casing to define a module; placing a heater between at least one of said aluminum casing and said plurality of energy cells; placing a sensor adjacent each pair of said plurality of energy cells to sense the temperature and/or power capacity of said pair of said plurality of said energy cells; and connecting a controller to each sensor adjacent each pair of said plurality of energy cells for receiving signals from said sensors to control the temperature and/or energy capacity of each pair of said plurality of said energy cells. [0019] In one embodiment the method comprises placing a plurality of modules in rows and columns. In another embodiment the controller is external to said module and activates the silicon heater when the sensor senses that the temperature of said pair of said energy cells falls outside a selected temperature range to heat the all said energy cells in a module.

[0020] In another embodiment of the method the controller deactivates the pair of said energy cells when the voltage of said pair of said energy cells falls outside a selected voltage level.

[0021] Moreover in yet another embodiment of the method the opposite aluminum holders comprise: a top aluminum extrusion and a bottom aluminum extrusion; and said silicon heater comprises:

(a) a top silicon heater disposed along the entire length of said top aluminum extrusion between said top aluminum extrusion and said plurality of energy cells; and;

(b) a bottom silicon heater disposed along the entire length of said bottom aluminum

extrusion between said bottom aluminum extrusion and said plurality of energy cells; and;

wherein said controller is external to said module; and wherein said method further includes powering said top silicon heater and said bottom silicon heater together to heat all said energy storage cells in a module.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Fig. 1 is a schematic view that illustrates the heater elements of a battery module designed to be utilized in battery packs and maintain an ideal temperature in sub-zero applications, according to certain embodiments of the invention.; where a battery pack incorporates a plurality of battery modules connected in either series or parallel

[0023] Fig. 2A-2B are perspective views of the invention integrated into different 36V battery module and 48V battery modules, according to certain embodiments of the invention.

[0024] Fig. 3A-3C are perspective views of other embodiments of module cells & cell holders that are utilized in plurality to assemble different variants of a battery module core, according to certain embodiments of the invention.

[0025] Fig. 4A-4B are perspective views of a 36V and 48V battery module cores found in Fig 2A-2B respectively. [0026] Fig. 5 illustrates a view of a 36Y battery module core integrated with the 36Y embodiment of the battery module end cap and the temperature sensors, according to certain embodiments of the invention.

[0027] Fig. 6 illustrates a view of a 48V battery module core integrated with the 48V

embodiment of the battery module end cap and the temperature sensors, according to certain embodiments of the invention.

[0028] Fig. 7A-7B illustrates a perspective view of the top and bottom module casing plus heater sub assembly in 36V configuration, according to certain embodiments of the invention.

[0029] Fig. 8A-8B illustrates a perspective view of the top and bottom module casing plus heater sub assembly in 48V configuration, according to certain embodiments of the invention.

[0030] Fig. 9 illustrates an exploded view of the 36V battery module according to certain embodiments of the invention.

[0031] Fig. 10 illustrates an exploded view of the 48 V battery module according to certain embodiments of the invention.

[0032] Fig. 11 A-l IB illustrate a cross-sectional view of the assembled battery module and the heating system according to certain embodiments of the invention.

[0033] Fig. 12 is a schematic view that illustrates a master controller and thermal management system interconnections with a plurality of battery modules within a battery back according to certain embodiments of the invention.

[0034] Fig. 13 illustrates the primary components of a battery pack including a plurality of battery modules within a battery pack enclosure and power shelf housing a master controller according to certain embodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0035] In the following description of the invention, embodiments of an energy storage system, in particular any embodiments utilized in thermal management system will be referenced in the accompanying drawings. These illustrations are intended to showcase the invention in practice. Wherever possible, corresponding or similar reference numbers will be used throughout the drawings to refer to the corresponding part.

[0036] The present invention and its embodiments serve the purpose to establish a thermal management system that is utilized to enable battery pack systems to operate in low temperature environments. By maintaining the temperature in a determined ideal range or selected range during operation, the overall battery pack performance is maximized or improved including the system power delivery and available capacity. In addition, this method of operating the battery pack, maintaining an ideal temperature will maximize or improve longevity by minimizing or lessening degradation due to cold or heat.

[0037] In FIG.l, an illustration of the main compromising component sub-assemblies of an energy storage module or energy storage device with a thermal management system. The energy storage battery module 100 is generally comprised of battery module end cap 101, battery module core 102, and battery module housing 103. The battery module housing 103 is designed to interlock with other modules to form battery packs. In addition, it is designed for passive module cooling creating a larger thermal mass absorb thermal energy, to be more fully described herein. It can also be fitted with an active heating system that is featured in the battery module casing or housing 103 as will be described. The battery module end cap 101 monitors & reports temperatures via sensors integrated with the battery module core 102, as described herein and provides a means to control the integrated heating system via an external master controller 110 having a 24 YDC power supply more fully particularized below.

[0038] The proposed invention can be integrated in to different battery module configurations with varying voltages and capacity. FIG.2A shows a perspective view of one example of a 36Y battery module 200 while FIG.2B shows a perspective view of one example of a 48V battery module 300. As shown in the illustration, the module housing 103 can be configured for different battery module cores 102 as illustrated for the 36V module housing 202 or the 48V module housing 302. Each battery module 200, 300 is capable of being controlled independently by a master controller 110. Each variation of a battery module 200, 300 can be connected electrically in series & or parallel configurations. This is achieved first by mechanically stacking the battery modules 200, 300 and placing stacks alongside each other in various grid like configurations.

The desired electrical configuration is achieved battery module 200, 300 electrical interconnects at the positive module terminal 206 and negative module terminal 207 as shown on the battery module 200, 300 in FIG. 2A-2B. It should be noted these series or parallel connections can be made with bus bars or a comparable alternative such as cable & lug connections. This will be explained further in the invention’s description. The module housing 103 is made up of a top and bottom 103t and 103b which integrate or connect with spaced energy cell holders and is designed for optimal mechanical stacking in addition to enabling passive cooling and active heating. Passive cooling is achieved by conduction through the aluminum and steel thermal mass making up the module housing 103. The activing heating portion of the thermal management is achieved via integrated heaters 701 within the module housing 103 which provides a controlled heat flow back into the battery module 100. The thermal management details will be further explained into the invention’s description. It should be noted the master controller 110 can control energy flow to each battery module and activate heaters to maintain an optimal or selected cell temperature range with a distribution of for example ±5 °C.

[0039] FIG.3A through to FIG.3B illustrate various cell blocks or energy cells 400, 410, 420 from which a plurality can be assembled together to form a battery module core 102. As shown in FIG.3A, a rechargeable battery cell or energy cell 401 is fitted with a bottom energy cell holder 402 and top energy cell holder 403 to assemble a standard cell block 400 The battery cell or energy cell 401 form factor is a prismatic can compromising in one embodiment an outer aluminum casing, positive cell terminal 407 and negative cell terminal 408. The thermal management system was designed according to the thermal/mechanical properties of the energy cell 401 to enable effective passive cooling and active heating through the module housing 103. The electrochemistry of the battery cell or energy cell 401 is NMC with for example a nominal voltage of 3.7 YDC & 50 AH capacity. However the invention can be utilized with other chemistries, form factors, and capacity. In another embodiment, shown in FIG.3B, an extremity cell block 410 is assembled with an extremity cell holder 404 instead of a top cell holder 403.

An extremity cell block 410 is specialized to terminate each end of a battery module core 102. In yet another embodiment, shown in FIG.3C a horizontal cell block 420 specialized for the use in multi row battery module core 600 as shown in FIG.4B and FIG.6. It is assembled using a horizontal cell holder 405 instead of the top cell holder 403 which enables the horizontal cell block 420 to interconnect with adjacent units 90 degrees relative to the standard cell block 400 orientation. It should be noted that the bottom cell holder 402, top cell holder 403, extremity cell holder 404, and horizontal cell holder 405 are comprised of suitable insulating material such as ABS but can alternatively be composed of any equivalent material with similar dielectric, thermal, and flame retardant properties. In addition to serve as an insulator between cells 401, the top cell holder 403 and extremity cell holder 404 feature holes that are fitted with inserts 406 which serve as mounting points for module housing 103 that contains the energy cells therein.

[0040] FIG.4A-4B illustrate two embodiments of a battery module core 102 which compromises of a plurality of different cell blocks 400, 410, 420 that are mechanically interlocked together under compression, strapped together, and electrically interconnected via bus bars (not shown) in series and parallel to form a battery module core 102, which is the energy storage component of the battery module 100. In one embodiment, a 36Y battery module core 102, 500 shown in FIG.4A where a plurality of cell blocks 400, 410 are configured in a 10 series / 2 parallel configuration. By 10 series we mean 10 cell pairs from 430a to 430j pairs; and by 2 parallel we mean 2 cells in a block 430. The parallel cell pair A 430a are made by connecting the negative cell terminals 408 and positive cell terminal 407 of adjacent. The next series connection of a pair of cell blocks 400, 410 shown as 430b in FIG.4A have their respective positive cell terminals 407 and negative cell terminal 408 connected in parallel. The interconnection between two cell block pairs 430a and 430b are connected from the first cell block pair A 430a positive cell terminals 407 to the adjacent cell block pair B 430b negative cell terminals 408. This is repeated to obtain the desired electrical which are then connected in series to get a nominal voltage of 36YDC and 100AH capacity. This embodiment utilizes standard cell blocks 400 with an extremity cell block 410 on either end which are compressed together from both ends before being strapped using core straps 501. It should be noted that each type of cell block 400, 410,

420 when interlocked with the adjacent unit has a minimum distance of 3 mm between each cell 401 face. This distance is to ensure the longevity of the overall battery module 100 as cells can expand overtime. This distance can vary depending on the utilized lithium cell in various embodiments. The energy cells 401 are thermally insulated from each other via the plastic cell holders (402, 403, 404, 405) and electrically isolated since in one embodiment the cell holders (402, 403, 404, 405) are comprised of ABS. In another embodiment, a 48V battery module core 600 is shown in FIG.4B which compromises primarily of standard cell blocks 400 to form the bulk of the module core 102, 600, extremity cell block 410 for the two opposite ends along with horizontal cell blocks 420 to maintain a compatible form factor for the module housing and thermal management system. In the case of the 48V battery module core there are 13 pairs of cell blocks 430a to 430m rather than the 10 pairs in 36V embodiment. In addition to active cell blocks 400, 410, 420 that provide the energy storage capabilities of the system, certain embodiments feature a core spacer 602 and or a block spacer 603 to maintain battery core shape when being compressed during the 48V core strap 601 installations. It should be noted that the 36V core strap 501 or 48V core strap 601 material is a flexible polypropylene plastic or equivalent material with enough strength to hold the cell blocks together while being electrically and thermally insulating. The core spacer 602 and block spacer 603 are comprised of suitable flexible material to accommodate any expansion or contraction due to thermal variation. [0041] As of the invention is to monitor the energy cell 401 temperatures must be monitored in order to regulate the heating system in each battery module 100 within a battery pack 1100 shown illustrated in FIG.12 which operates in less than for example 0°C or other selected ambient condition. FIG.5 illustrates a 36Y battery module 200 view without the outer 36Y module housing 202 specifically looking at the cell tab side where you can see the energy cell’s 401 positive cell terminal 407 and negative cell terminal 408 of the cell blocks. The 36V end cap 201 shows a battery monitoring module inside its encasement responsible for collecting voltage and temperature data on each module and reporting it to a master controller 110 located on the power shelf 1102 inside the battery pack 1100b as shown in FIG.13 for example. Voltage sensors 209 are placed at every series connection while the temperature sensors 205 are placed in a way to map out the temperature distribution within a battery module core 102 from the extremities to the center. The 36V end cap 201 is integrated with a 36V battery module core 500 via a sensor probe harness (not shown) with three temperature sensing thermistors 205 (see FIG.6) that are applied to the first, middle and end cell 401 in the 36V battery module core 500. However any number of thermistors 205 can be used. The voltage sensors 209 are placed on each serial connection for a total of 10 in the 36V module core 500. In another embodiment shown in FIG.6, the 48V battery module 300 is shown without the outer 48V module housing 302. The 48V end cap 301 with a battery monitoring module with a 48V version of the sensor probe harness (not shown) that is integrated or connected with the 48V module core 600. In this embodiment, four temperature sensing thermistors 205 are applied to the first, middle, end cell, and horizontal cell with sensor positions pointed out in FIG.6. Similarly there are voltage sensors 209 placed at every series connection for a total of 13 also shown in FIG.6. However in alternate embodiments different battery modules can be configured with varying number of sensors for different battery module cores 102.

[0042] The thermal management system of the present invention manages the heat flow in and out of the battery module core 102 through the battery module housing 103. It compromises of a top and bottom casing or housing 103t and 103b in addition to side plates 203 and 303 shown in the explosion views in FIG.9-10. FIG.7A-7B illustrate 36V top casing 800 (or top housing 103t) and 36V bottom casing 700 (or bottom housing 103b) that make up the top and bottom portions of the 36V module housing 202. Both casings or housings are made of an aluminum case extrusion 702 integrated with a silicone rubber resistive heater pad 701 via a pressure adhesive. Other materials can also be used that perform the same function. The heater pads 702 feature leads that are connected to the 36Y end cap 201 during the installation. The heater pad 701 features for example up to 40W of power, thermally conductive silicone rubber and electrically isolating between the cell and the outer aluminum casing. The power density can be adjusted for different embodiments of the outer module housing 103 and different types of battery cells 401. In another embodiment the thermal system can be fitted with thermoelectric peltier devices as a substitute for the heater pads 701. It should also be noted that the silicone rubber material encasing the resistive heater can be composed of a comparable material with similar thermal conductivity and electrical isolation.

[0043] In another embodiment of the invention, in order for the casing or housing to be mounted the battery core the case extrusion 702 has a plurality of mount holes 704 purposed for different battery module assemblies. Particular mount holes 704 are fitted with pern nuts 703 in FIG.7A and FIG.7B to enable 36Y side plates 203 installation better shown in the explosion view of the 36V battery module 200 in FIG.9. In another embodiment, as shown in FIG.8A to FIG.8B, 48V bottom casing 900 or 103b and the 48V top casing 1000 or 103t are configured via a different set of pern nut 703 installation points. These set of casings are utilized with a 48V battery module core 600. It should be noted that the-extrusions 702 are designed to be asymmetrical to allow module stacking regardless of the battery module core 102 construction for better stability. The opposite side of the pern nut 703 installation on each aluminum (although other materials other than aluminum can be used) case extrusion 702 feature additional mount holes 704 to enable mounting to the inserts 406 on the top cell holder 403 and extremity cell holder 404.

[0044] The assembly of the embodiments making up the thermal management applied in a 36V battery module 200 are shown in an FIG.9 explosion view. The 36V end cap 201 integrated with the 36V battery module core 500 form the main sensory intake portion of the system, collecting temperature data on the energy cells 401 and reporting it to the master controller 110. FIG.12 illustrates an example of a communication and thermal management backbone within a battery pack 1100. The master controller 110 is electrically interconnected with a plurality of battery modules 100 via a single or plurality of intermodule harnesses 111 through which

communication data and heater power is sent through between the master controller 110 and battery modules 200, 300. Each harness 111 is connected to the battery module com port 208 better shown in FIG.2A-2B at the front of each battery module 200, 300. Each com port 208 provides power, communication, heater power to the battery module end caps 201, 301. The method by which the thermal management system provides passive cooling and active heating is achieved via the 36Y module housing 202 and master controller providing 24Y power source to the heaters 701 via the 36V end cap 201. The 36V bottom casing 700 and 36V top casing 800 are both installed onto the sides of the 36V battery module core 500 where the silicone rubber pad with an isolated resistive heater interfaces with the plurality of cells 401. The passive cooling is achieved via the case extrusion 702 by conduction. The top and bottom casings or housings 103t, 800 and 103b, 700 are joined together via the 36V side plate 203 to both add additional thermal mass and structural rigidity. The side plates 203 are installed via the inserts 406 on the front right side of the 36V module core 500 and pern nuts 703 on the top and bottom casing. In addition to insulating the module further and providing structural support, the 36V module end plate 204 closes off the back end of the 36V battery module 200.

[0045] In another embodiment of the invention, the breakdown of components making up thermal management system applied in a 48V battery module 300 configuration are shown in FIG.10 explosion view. The 48V end cap 301 integrated with the 48V battery module core 600 provides the sensory input just as the 36V embodiment with additional thermistor 205

temperature sensor given the larger form factor and additional cells 401 to manage within the 48V module core 600. The master controller 110 provides power to the heaters in a similar manner to the 36V embodiment described above but may utilize different control algorithms within the master controller 110 to achieve the appropriate selected temperature or temperature range. The 48V bottom casing 900 and 48V top casing 1000 form that main thermal conductive pathway to the plurality of cells within the 48V module core 600. The heat is generated from the two heating pads 701, and alternatively allows excessive heat to pass through into the aluminum case extrusions 702 as a heat sink. The 48V side plates 303 provide an additional structural rigidity and thermal mass increasing ability to spread the generated heat throughout the module for an evenly distributed heat transfer. Each 48V side plate 303 are mounted via the inserts 406 and pern nuts 703 that have been configured for the 48 V battery module core 600.

[0046] As shown in FIG.l 1A, a cross sectional view of the 36V battery module 200 showcasing 36V module housing 202 encasing the 36V module core 500. As shown in the cross section the standard cell blocks 400c is encased between the 36V top casing 800, 103t & 36V bottom casing 900, 103b. As shown in FIG.l 1 A the module is fitted with two heater pads 701 (although a number of pads could be used) for a total of 80W of available power compressed onto a plurality of the cell 401 faces. Heat flow can go in either direction at this interface. The aluminum case extrusions 702 act as heat sinks during normal operation wicking excessive heat through the inactive silicone rubber heater 701. Similarly, in another embodiment as shown in FIG.1 IB, a cross-section view of the 48Y battery module 300, illustrates the 48Y battery module core 600 encased in the 48V module housing 302. FIG.1 IB showcases the cross sectional view of the standard cell blocks 400c and cross sectional horizontal cell blocks 420c in different orientations making contact with the two 40W heater pads 701 for a total of 80W. The cross sectional view illustrates the interlocking features of the case extrusion 702 which allow different battery modules to be interlocked and stacked with each other physically to create dense battery pack systems. These battery packs can have a plurality of 36V battery modules 200 and 48V battery module 300 interconnected in series or parallel. In addition to providing localized heating to specific battery modules 100, different methodologies can be employed on the pack level such that the master controller 110 activates adjacent module heaters 702 more frequently to heating towards more critical modules. The invention as presented can dynamically adjust in order to maintain optimal cell 401 temperatures reported through the thermistors 205. This control is conducted via power pulse of 24V at different frequencies to establish an adjustable RMS power through the master controller 110. In addition to the dynamic control in expanded systems, the thermal mass and interlocking features in the battery modules 100 allow a greater ability to passively cool the system in heavier load applications. The battery pack 1100 can be fitted with a larger outer enclosure 1101 for an additional thermal mass and insulation from outer ambient conditions. FIG.13 conceptually illustrates a possible embodiment of a battery pack 1100b featuring 10 battery modules 100b (shown in from the front face perspective) configured mechanically in a 2 by 5 battery pack core 1103, a power shelf 1102 with a master controller 110b (shown as a mechanical sub assembly inside), and a battery pack enclosure 1101. FIG.13 can also better illustrate a possible embodiment of a plurality of battery modules 100b stacked on top of each other and joined side to side to form multiple thermal conduction pathways in addition to the outer battery pack enclosure 1101.

[0047] As previously mentioned, the battery modules 100 also feature voltage sensors 209, which is reported to the master controller 110. If a voltage is detected outside a preset boundary conditions, that said battery module can be electrically isolated from the battery pack 1100 common power bus through the battery module end cap 101 at the command of the master controller 110. In addition to protecting battery modules from loads or charge sources during these specified voltage points, it can terminate its heating power supply if any one cell 401 is outside its acceptable voltage range. This is to prevent events such as over discharging or isolating the heating system in some other event where one of the battery modules 100 are compromised in any way.

[0048] The invention described herein describes a modular heating system for energy storage devices comprising: a plurality of energy cells in spaced adjacent configuration; spaced aluminum holders for holding said plurality of spaced energy cells between said opposite aluminum holders to define a module; a heater disposed between at least one of said aluminum holders and said plurality of energy cells; a sensor adjacent each pair of said plurality of energy cells to sense the temperature and/or power capacity of said pair of said plurality of said energy cells; and a local controller connected to each sensor adjacent each pair of said plurality of energy cells for receiving signals from said sensors to control the temperature and/or energy capacity of each pair of said plurality of said energy cells.

[0049] Furthermore the invention describes a method for energy storage for sub-zero

applications comprising: placing a plurality of energy cells in spaced adjacent configuration; holding said plurality of spaced energy cells between opposite aluminum holders to define a module; placing a silicon heater between at least one of said aluminum holders and said plurality of energy cells; placing a sensor adjacent a pair of said plurality of energy cells to sense the temperature and/or power capacity of said pair of said plurality of said energy cells; connecting a controller to each sensor adjacent each pair of said plurality of energy cells for receiving signals from said sensors to control the temperature and/or energy capacity of each pair of said plurality of said energy cells.

[0050] The present invention has been described in an illustrative manner. It is to be understood that the terminology which has been used is intended to be describe the invention rather than be a limitation. Many modifications and variations of the present invention are possible. It should also be noted that the presented embodiments are specialized towards cold applications and can be adjusted for different varying conditions. Therefore, within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described.

LIST OF ELEMENTS

100 Battery Module

100b Battery Module - box view

101 Battery Module End Cap

102 Battery Module Core

103 Battery Module Housing

103t Top Module Housing / Casing b Bottom Module Housing / Casing Master Controller

b Master Controller - box view Intermodule Harness

36V Battery Module

36V End Cap

36V Module Housing

36V Side Plate

36V Module End Plate

Thermistor

Positive Module Terminal Negative Module Terminal COM Port

Voltage sensor

48V Battery Module

1 48V End Cap

48V Module Housing

48V Side Plate

48V Module End Plate

Standard Cell Block

c Cross-section standard cell block1 Battery Cell /

Bottom Energy Cell Holder Top Energy Cell Holder

Extremity Energy Cell Holder Horizontal Energy Cell Holder Insert

Cell Positive Terminal

8 Cell Negative Terminal

0 Extremity Cell Block

0 Horizontal Cell Block

Horizontal Cell Block-Cross-c section view

a Cell Block Pair A

b Cell Block Pair B

0 36V Battery Module Core1 36V Core Strap

0 48V Battery Module Core1 48V Core Strap

2 Core Spacer

3 Block Spacer

0 36V Bottom Casing

1 Heater Pad 702 Case Extrusion

703 Pem Nut

704 Mount Hole

800 36V Top Casing

900 48V Bottom Casing

1000 48V Top Casing

1100 Battery Pack

1100b Battery Pack - box view

1101 Battery Pack Enclosure

1102 Power Shelf

1103 Battery Pack Core

Claims

1. An electrical energy storage device comprising:

(a) a plurality of spaced energy cells;

(b) spaced holders for holding said plurality of spaced energy cell there between;

(c) at least one heater associated with at least one of said holders for heating said spaced energy cells at a selected temperature range;

(d) sensor means for sensing the temperature of said spaced energy cells;

(e) a controller for controlling said heater to heat said spaced energy cells to said selected temperature range.

2. The electrical energy storage device claimed in claim 5, wherein said controller deactivates a module that falls below a selected power capacity.

3. An electrical energy storage device as claimed in clam 1, wherein said heater is comprised of silicone rubber encasing a resistive wire.

4. An electrical storage device as claimed in claim 3, wherein said spaced holders comprise extruded aluminum.

5. An electrical storage device as claimed in claim 4, wherein said spaced holders comprise a top holder and bottom holder for holding said spaced plurality of energy cells there between in a module.

6. An electrical energy storage device as claimed in claim 5, wherein said silicon heater is disposed between one of said top and bottom holders, and said plurality of energy cells.

7. An electrical energy storage device as claimed in claim 6, wherein said energy cells

comprise an NMC battery.

8. An electrical energy storage device as claimed in claim 7, wherein said plurality of energy cells are disposed in pairs.

9. An electrical energy storage device as claimed in claim 8, wherein each said pairs of

energy cells include a voltage sensor.

10. An electrical energy storage device as claimed in claim 9, wherein each said module

includes a plurality of temperature sensors.

11. An electrical energy storage device as claimed in claim 10 wherein said module comprises one of;

(a) a 36 volt module and has three temperature sensors; or

(b) a 48 volt module and has 4 temperature sensors.

12. An electrical energy storage device as claimed in claim 10, further comprising a relay

disposed in an end cap of said module.

13. An electrical energy storage device as claimed in claim 10, wherein each said energy

storage device includes a top and bottom cell holder.

14. A modular heating system for energy storage devices for comprising:

(a) a plurality of energy cells in spaced adjacent configuration;

(b) spaced aluminum holders for holding said plurality of spaced energy cells between said opposite aluminum holders to define a module;

(c) a heater disposed between at least one of said aluminum holders and said plurality of energy cells; (d) a sensor adjacent each pair of said plurality of energy cells to sense the temperature of said pair of said plurality of said energy cells;

(e) a controller connected to each sensor adjacent each pair of said plurality of energy cells for receiving signals from said sensors to control the temperature of each pair of said plurality of said energy cells.

15. A modular heating system for energy storage devices as claimed in claim 14 wherein said silicon heater comprises:

(a) a single top silicon heater disposed along the entire length of a top extrusion between said top aluminum holder and said plurality of energy cells; and;

(b) a single bottom silicon heater disposed along the entire length of a bottom aluminum holder and said plurality of energy cells.

16. A method for energy storage for sub-zero applications comprising:

(a) placing a plurality of energy cells in spaced adjacent configuration

(b) holding said plurality of spaced energy cells between opposite aluminum holders to define a module;

(c) placing a heater between at least one of said aluminum holders and said plurality of energy cells;

(d) placing a sensor adjacent each pair of said plurality of energy cells to sense the temperature of said pair of said plurality of said energy cells;

(e) connecting a controller to each sensor adjacent each pair of said plurality of energy cells for receiving signals from said sensors to control the temperature of each pair of said plurality of said energy cells.

17. A method for energy storage as claimed in claim 16 including placing a plurality of

modules arranged in rows and columns.

18. A method as claimed in claim 16 wherein said controller is external to said module and activates said silicon heater when said sensor senses that the temperature of said pair of said energy cells falls outside a selected temperature range to heat the all said energy cells in a module.

19. A method as claimed in claim 16 wherein said opposite aluminum holders comprise: a top aluminum extrusion and a bottom aluminum extrusion; and said silicon heater comprises:

(b) a bottom silicon heater disposed along the entire length of said bottom aluminum extrusion between said bottom aluminum extrusion and said plurality of energy cells; and;