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Battery Management System (BMS) for a Solar Powered Racer

Revision 1

ECE 4007 Senior Design Project

Section L01, Solar JacketsBattery Management Team

Project Advisor: Dr. Whit Smith

Prepared by:

Mark Slade

Daniel Christopher

Daniel Paul Martin

Ali Bibonge

Taverishima Tsegha

Submitted

September, 26 2011


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Table of Contents

Executive Summary.............................................................................................................4

1. Introduction......................................................................................................................5

1.1 Objective............................................................................................................5

1.2 Motivation..........................................................................................................5

1.3 Background........................................................................................................6

2. Project Description and Goals..........................................................................................7

2.1 Description.........................................................................................................7

2.2 Goals...................................................................................................................8

3. Technical Specification....................................................................................................8

3.1 Physical Specifications.......................................................................................8

3.2 Lithium-Ion Battery Specifications...................................................................10

3.3 Microcontroller Specifications..........................................................................10

3.4 MOSFET Specifications....................................................................................11

3.5 LTC Specifications............................................................................................11

3.6 Temperature Sensor IC Specifications..............................................................12

4. Design Approach and Details..........................................................................................13

4.1 Design Approach...............................................................................................13

4.2 Codes and Standards..........................................................................................16

4.3 Constraints, Alternatives, and Tradeoffs............................................................17

5. Schedule, Tasks, and Milestones......................................................................................18

6. Project Demonstration......................................................................................................18

7. Marketing and Cost Analysis............................................................................................19


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7.1 Marketing Analysis.............................................................................................19

7.2 Cost Analysis......................................................................................................20

8. Summary...........................................................................................................................21

9. References.........................................................................................................................23

Appendix A...........................................................................................................................25


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Executive Summary

The Solar Jackets club at Georgia Tech is building a solar powered racer to compete in a

1200-1800 mile cross-country American Solar Challenge in summer 2012. The battery

management system (BMS) project is a continuation of the design that began in January 2011 by

the previous ECE 4007 senior design class. The BMS system proposed will be designed to

monitor, regulate, and maintain the solar powered lithium-ion (Li-ion) rechargeable batteries that

power the Solar Jackets racer. The racer will be powered by three battery packs connected in

parallel containing 30 Li-ion cells each. The battery packs will supply the 96V required for the

motor and a 12V bus to power all peripheral equipment such as microcontrollers. During the

race, it is required that an active method of circuitry protection be utilized to continually monitor

and regulate the over-voltage, under-voltage, over-current, and over-temperature of the Li-ion

battery cells. Communication with other systems in the racer will be achieved via a RS-485

network being designed by another Solar Jackets team.


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1. Introduction

The Solar Jackets team at Georgia Tech is building a solar powered racer to compete in

the 2012 American Solar Challenge. This is an ongoing project with a new design team to

continue from where the spring 2011 team stopped. The Solar Jackets battery monitoring system

(BMS) team has a $410 budget from Georgia Tech to develop and build a custom BMS, a

subsystem of the solar power system in the racer.

1.1 Objective

The spring 2011 BMS group left a semi-functional battery management system that could

successfully measure individual cell voltages in a controlled environment. This semi-functional

BMS could also communicate via the RS-485 network and determine whether to turn on or off

each battery pack. The objective this semester is to get the current and temperature monitoring

components of the BMS functional as well as potentially polishing the voltage monitoring aspect

of the BMS [1]. The RS-485 communication protocol will be designed and managed by another

Solar Jackets design group; the BMS will only provide the data acquired from the battery packs.

1.2 Motivation

The Solar Jackets want to have a fully functional car by December 9, 2011. A working

prototype must be produced as well as being integrated into the BMS system with the other

aspects of the car by this date. There will be a total of 90 lithium-ion (Li-ion) cells in the car and

safety is critical. These Li-ion cells are capable of exploding if the temperature exceeds 85C and

be damaged if the voltage drops below a certain threshold. A BMS system is necessary to ensure

that the batteries are maintained within the desired operating conditions. Without a battery

management system, the driver would need to repeatedly check on the batterys health himself


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[1]. A custom design BMS will produce a more cost effective means for monitoring and

managing the batteries for the Solar Jackets. It will also allow the Solar Jackets to better

understand how to deal with large currents and other various characteristics that are expected

from the system.

1.3 Background

Every battery management system does three things. It should monitor how the battery is

doing via current, voltage, and temperature. The BMS should balance the charge among the

various battery packs. Also, it should protect the batteries with warning stages and even go as far

as to manually shut off if the batteries reach a critical state in which they could be permanently

damaged or combust [1]. Due to the fact that this will be the second group to work on this

specific design, much of the background research deals primarily with the aspects not

successfully dealt with in the previous term. Specifically, the process of circuit breaking the

battery packs in case of reaching a critical state, the specific batteries that will be implemented,

and the LTC chip used to measure various characteristics of the Li-ion batteries have all been

examined.

Li-ion batteries will be implemented for this design of the BMS. These batteries are the

most popular batteries on the market. They are a rechargeable battery type in which lithium ions

move from the negative electrode to the positive electrode during discharge and the process is

reverse when charging [2]. The use of Li-ion batteries has increased in the past decade due to

their ability charge quickly, great energy density, and relatively slow loss of charge [3].

MOSFETs will be used as circuit breakers to isolate certain battery packs when some

aspect of the pack is not within the allowable range for temperature, voltage, or current.

MOSFETs are voltage driven devices constructed with four major sections: source, drain, gate,


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and body. They are comprised of semi conductor, insulator (silicon dioxide) and a metallic

component. When the voltage between the gate and source terminals is below a specified

threshold (typically 27mV), there is no channel for conduction which is how we will switch the

battery packs on and off [4]. In order to properly use MOSFETs as switches, the digital output

from a microcontroller to push the MOSFETs through an amplifying gate driver will be used.

Embedded microcontrollers can be found in technologies and items such as televisions,

cell phones, automobiles, or any high-end computer. The underlying software used to produce

functionality with microcontrollers is the C/C++ programming language [5]. A gate driver at its

most basic definition is a power amplifier. Its purpose is to take a low current value that is often

coming from a digital source and output a high current value capable of driving FETs into a

different state for initializing circuit breaking [6].

The LTC6802 that will be used in the BMS is a complete battery monitoring IC that

includes a 12-bit analog-to-digital converter, a precision voltage reference, a high voltage input

multiplexer, and a serial interface. Each of the 12 cell inputs has an associated MOSFET switch

that can discharge any cell that becomes overcharged [3]. The BMS will be using this LTC chip

to measure both voltage and current in the battery packs.

2. Project Description and Goals

2.1 Description

The BMS will be designed to provide measurements of the voltage of individual batteries

in each pack, the current flowing in or out of the battery pack, and the temperature of the battery

pack. Predetermined limits will be selected in order to provide safe operating conditions for the

batteries. If any of these limits are exceeded, a system shutdown will occur. The battery packs


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will consist of thirty 3.2V cells that will be provided by the Solar Jackets. A source of 96V will

be attained by connecting each of the thirty cells in series. A battery pack containing the 30 cells

has been assembled and will be implemented with the BMS.

Identical printed circuit boards will be designed and will contain components for

measuring the voltage of each cell, the current at the connection of each battery pack, and

temperature at various locations in the battery pack. The measurements obtained from the

sensors will be read by a Microchip PIC24 microcontroller. Continuous monitoring of the

sensors from the microcontroller will allow for system stability and allow for the capability of

disconnecting the battery pack if necessary. The microcontroller will be connected to the cars

computer system to report its status and receive commands to connect and disconnect the pack.

2.2 Goals

Program microcontroller to read sensor data and determine state of battery system

Monitor individual cell voltages, temperature, charge/discharge current

Satisfy cooling requirements

Implement safety shut off system

Send/receive data and commands with computer

3. Technical Specifications

3.1 Battery Pack Specifications

Three independently monitored battery packs all work together to power the solar

vehicle. The specifications for one of these battery packs are listed in Table 1 [1]. The choice of

batteries was chosen by the Solar Jackets officials. The battery packs will output at 96V for the

motor and also supply the 12 V power used by the all other electronics in the vehicle.


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Additionally, size constraints will play a critical role and are also listed in Table 1 [1]. The BMS

is designed to keep the batteries within the manufacturer's operational specifications [7] and will

shutdown operation whenever safe limits are exceeded.

Table 1. Pack Specifications

Battery Make Headway Headquarters H-38120SBattery cells per pack 30Number of packs 4Motor output voltage 96 VPeripheral output voltage 12 VMicrocontroller PIC24F16KA102Communication Protocol RS 485Maximum mass 10 kgMaximum width 20 inchesMaximum length 22 inchesMaximum height 8 inches


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3.2 Lithium-Ion Battery Specifications

The Headway 38120S Li-ion batteries were selected by the Solar Jackets officials. The

specifications can be seen in Table 2 [7].

3.3 Microcontroller Specifications

PIC microcontrollers will be used to monitor the batteries and relay such information to

the rest of the vehicle. Each individual microcontroller will have a unique hardware identity used

to communicate among the RS-485 bus, programmed with jumper on the primary board. Each

monitoring PIC microcontroller operates in slave mode and waits for a ping before sending its

response. Table 3 shows the specs on the PIC microcontroller chosen [8].

Table 2. Headway 38120S(10AH)

No. Item Specification

1 Normal capacity 10000mAh

2 Normal Voltage 3.2V

3 Inter Impedance


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Table 3. Microcontroller Specifications

Microcontroller PIC24F16KA102Architecture 16-bitCPU Speed (MIPS)

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Memory Type FlashProgram Memory (KB) 16RAM Bytes 1,536Temp Range (C) -40 to 125Operating Voltage 1.8 to 3.6I/O Pins 24Internal Oscillator 8 MHz, 32 kHzTimers 3 x 16-bit

3.4 MOSFET Specifications

The MOSFET will be used for isolating the battery packs when over-voltage, under-

voltage, over-current, and over-temperature limits are reached. The MOSFET specifications are

shown in Table 4 [9].

Table 4. MOSFET Specifications

MOSFET INFK230N20TVDSS 200VIDSS 230ARDS(on) 7.5mtrr 200ns

3.5 LTC Specifications

The LTC IC will interface between the PIC microcontroller and the battery cells. It will

be used to measure/balancing voltages and measuring current. The specifications for the LTC IC

are shown in Table 5 [10].


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3.6 Temperature Sensor IC Specifications

An LM35D integrated-circuit will be used as the temperature sensor. We favored it

because its output voltage is linearly proportional to the Celsius (Centigrade) temperature. The

LM35 thus has an advantage over linear temperature sensors calibrated in Kelvin, as the user is

not required to subtract a large constant voltage from its output to obtain convenient Centigrade

scaling. The LM35 does not require any external calibration or trimming to provide typical

accuracies of 14C at room temperature and 34C over a full 55 to +150C temperature

range. Its low output impedance, linear output, and precise inherent calibration make interfacing

Table 5. LTC Specifications

Total Supply Voltage (V+ to V) 60V

Input Voltage (Relative to V)

C1 0.3V to 9V

C12 V+0.6V to V+ + 0.3V

Cn 0.3V to min (9 n, 60V)

Sn 0.3V to min (9 n, 60V)

CSBO, SCKO, SDOI V+0.6V to V+ + 0.3V

All other pins 0.3V to 7V

Voltage Between Inputs

Cn to Cn-1 0.3V to 9V

Sn to Cn-1 0.3V to 9V

C12 to C8 0.3V to 25V

C8 to C4 0.3V to 25V

C4 to V 0.3V to 25V

Operating Temperature Range 40C to 85C

Specified Temperature Range 40C to 85C

Junction Temperature 150C

Storage Temperature Range 65C to 150C


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to readout or control circuitry easy. It can be used with a single power supply, or with plus and

minus supplies. As it draws only 60 A from its supply, it has very low self-heating which is

extremely important in proper temperature sensing. Table 6 shows the specifications for the

LM35DT temperature sensor [11].

4. Design Approach and Details

4.1 Design Approach

The topology of one battery pack for the BMS is shown in Figure 1. The system contains

three battery packs in parallel. In each pack 30 cells are put in series to produce a total voltage of

96 Volts DC when fully charged. In theory, this topology allows for a maximum current draw of

400A by the motor since each pack has the capacity to produce 100A. All cable conductors will

be sized accordingly even though the motor will not draw a current that high.

Table 6. LM35DT Specifications

Manufacturer Range Supply voltage accuracy

National Semiconductor -55C ~ 150C 4 V ~ 30 V 0.6C


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Each pack will be connected to the main bus through three different disconnects: a fuse, a

computer controlled electronic switch, and a manual switch. A 12V bus from each battery pack

will be used for all computers and peripheral equipment in the racer. The 30 cells in each pack

will be placed between two printed circuit boards that contain the LTC ICs for voltage and

current measuring of the individual battery cells. The LTC layout can be seen in Figure 2.

Operational amplifiers that can operate at high voltages (above 50V) will be used to measure the

cells voltages and currents. LM35 sensors will be used to measure the temperature of each

battery pack [11].

Figure 1. BMS block diagram for an individual pack.


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A PIC24F16KA102 microcontroller will be used in each individual battery pack as a

small computer to monitor the batteries health. All sensors will feed through a multiplexor,

allowing the PIC to ping each sensor individually and determine whether the batteries are

healthy. The PIC will have the ability to cut off the batteries from the load or the solar cells

automatically if either voltage is too high in a certain cell or if the motor is drawing too much

current. The PIC will also cut off a pack if the temperature of an individual cell is over 45 C. In

Figure 2. LTC chip layout.


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addition to monitoring, the microcontroller will deliver data such as charge levels, voltage levels,

average current draw, and temperatures to the motor control computer via RS 485.

Battery balancing will be implemented due to the imperfect nature of the individual

battery cells. Some cells may charge faster than others. Battery balancing will ensure all batteries

within a pack have the same charge level. Implementing this for each battery would require

either bypass or current limiting circuitry for each battery. If a certain battery cell has a higher

voltage than the others, it will be bypassed or the current to it will be limited while the others

continue charging normally. Given the topology presented above, bypassing a cell would drop

the voltage of the pack and cause it to be a lower voltage than the bus. A pack with a lower

voltage than the bus would cause the other packs to discharge into it, possibly causing an

unwanted increase in temperature. The solution to the problem would be to disconnect a pack off

from the bus once one cell in a pack exceeds 3.65V. That would force the highest cell to

discharge into the others and bring the whole pack to a uniform voltage. Once the voltage of the

pack has gone down slightly, the pack will reconnect.

4.2 Codes and Standards

The BMS complies with all electrical regulations set in the 2012 American Solar

Challenge (ASC) Regulations [12]. The regulations define the requirements to electrically isolate

the battery system in case of an emergency shutdown. At the time of this proposal an email was

sent to the ASC requesting information on the acceptability of MOSTFETs as a means of

electrically isolating the Li-ion packs. The communication to the other systems in the solar car

utilizes the RS-485 protocol that is being designed by another Solar Jackets design group. Each

pack will operate as a slave on the bus with its own unique device identity. All messages sent to


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other systems in the vehicle will be sent in 8-bit plain text ASCII. Each message will be

terminated by a check sum followed by the end-of-line character.

4.3 Constraints, Alternatives, and Tradeoffs

The battery pack, the topology of cells and sensors were designed by the previous senior

design group. Using three separate battery packs in parallel was chosen because it is easier to test

the smaller battery packs and it does not create a single point of failure. The connection style of

putting the batteries between two custom copper clad boards was chosen to simplify wiring and

make attaching voltage sensors easy. This decision requires that the voltage sensors measure two

cells at a time because each circuit board only has every other cell connection available. This can

be compensated via software by subtracting the voltages from each board to obtain each

individual voltage.

The most difficult constraint is tolerance of the natural variation of the 90 cells in the

three battery packs. These variations can cause the cells to charge and discharge at different

rates, and none of the cells can be allowed to exceed maximum and minimum charge constraints

without shortening their lifetime. It is possible to disconnect a single cell that is charging at a

different rate but that would require the addition of an enormous amount of circuitry. The added

complexity could extend the design project beyond the time allocated. The alternative chosen

was to simply turn off each pack entirely whenever any of its cells exceeds its parameters. This

increases the odds of a single pack being disconnected, and therefore will require tighter

monitoring of the battery packs.

In addition to these design constraints, the completed BMS must meet all requirements

imposed by the contest rules and the design of the Solar Jackets car. This includes safety

requirements such as cooling fans and emergency stop switches being designed by another Solar


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Jackets design group. The battery pack dimensions are dictated by the size of the cells, which

have been pre-specified by the Solar Jackets.

5. Schedule, Tasks, and Milestones

The BMS project schedule is to have a working prototype by the week of October 17,

2011. The Solar Jackets have set a schedule to have a fully-functional BMS in the second week

in December. Table 7 shows a summary schedule of the BMS project. A more detailed project

schedule can be found in Appendix A.

6. Project Demonstration

In conclusion of the Fall semester, three battery packs will be completely assembled and

tested to ensure that each pack delivers an output voltage of 96V. Individual battery packs will

be capable of being charged and the control software for each battery pack will be demonstrated.

The software will show that no single battery contained within each battery pack becomes over-

charged, under-charged, or over-heated. Following this, the interactions of all three packs will be

Table 7. Summary Schedule of BMS Project

Task Name Duration

Purchase Parts 7 days

Build Prototype 8 days

Design PCB 12 days

Program PIC24 9 days

BMS Fabrication 0 days

BMS Install/Test 7 days

Final Presentation 0 days


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demonstrated in order to show that the BMS has the ability to allow for each battery pack to

properly charge when each battery pack is initially at a different voltage level.

After successful testing/demonstrations, the entirety of the BMS will be integrated into

the Solar Jackets racer and provide a consistent supply of 96V to power the motor. Due to the

fact that all components of the racer may not be completed by the end of the semester, an

alternative testing method will be used. This method will use a power supply to charge the

battery packs and measurements will be displayed on a computer using HyperTerminal.

7. Marketing and Cost Analysis

7.1 Marketing Analysis

While other battery management systems are commercially available, the constraints and

the power efficiency used in our system is not currently available on the market [1]. Our

interpretation of this design will succeed previous iterations and will incorporate features that

will enhance the functionality of the device. The nature of the vehicle requires that each

management system be able to operate with a current of 100A [1]. However, most systems today

can handle only a maximum of 15 cells per pack. This constraint would require two BMS boards

to be used per pack. An implementation like this would reference all the control signals against a

48 V ground for the upper half of the battery packs [1]. This result would not meet the ASC

standards. The systems that meet the required 96 V for the motor will fail to have the required

current capacity [13]. Most available commercial systems do not have the capability to manage

battery packs in a parallel system. These systems manage the cells during charging in an attempt

to equalize the charges on each cell, which can result in the packs having different voltages from


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one another [1]. Even if todays systems are used in parallel, they are not cost friendly to

consumers in the market.

7.2 Cost Analysis

The BMS for the Solar Jackets solar vehicle will cost an estimated $26,476.10 for

equipment and development. Table 8 gives a full listing of the parts used to make the BMS.

Table 8. Equipment Costs

Product Description QuantityUnit PricePrice Amount Purchased

BMS IC chip LTC6802 3 $13.86 $41.58 $0.00

PIC24F16KA102 microcontroller 1 $2.70 $2.70 $0.00

External Oscillator 1 $2.13 $2.13 $0.00

Phone jack 1 $4.54 $4.54 $0.00

Current sensor 1 $7.00 $7.00 $0.00

RS 485 transceiver 1 $6.30 $6.30 $0.00

High power MOSFETs 3 $9.50 $28.50 $0.00

Gate driver 1 $1.36 $1.36 $0.00

DC/DC converter 1 $4.22 $4.22 $0.00

Voltage differential amplifier 1 $2.45 $2.45 $0.00

Connector 1 $4.58 $4.58 $0.00

PCB, low-current board 1 $350 $350 $0.00

PCB, high current board 1 $100 $100 $0.00

Resistors 47 $0.01 $0.24 $0.00

Diodes 9 $0.01 $0.07 $0.00

Capacitors 11 $0.03 $0.33 $0.00

Op-Amps 1 $0.50 $0.50 $0.00

Pin headers 4 $0.20 $0.80 $0.00

LM35DT 20 $0.94 $18.80 $0.00

Total Cost $576.10


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The BMS team has all the parts needed to construct a prototype in the Solar Jackets lab.

Therefore, the need to purchase products will be at a minimum. The development costs for the

BMS are shown in Table 9. Labor rates are set at $35 per hour for the workforce. The majority of

the time and effort will be spent under BMS circuit design, due to the difficulties in trying to

balance the charge on all battery cells and preventing malfunctions in the situation that two packs

become charged to different levels.

8. Summary

The goal is to have a fully working and functional BMS by December 9th, 2011.

Currently, the BMS has been skeletally tested to demonstrate about 25% functionality; it is able

to measure the voltage levels of the battery cells and determine whether or not to switch on the

battery packs. It is also able to receive request for status and send responses back. These

functions were tested using the PIC18 microcontroller which is being upgraded to a PIC24

Table 9. Development Costs

Component Labor HoursLabor CostEquipment CostTotal Component Cost

Microcontroller Coding 80 $2,800.00 $0.00 $2,800.00

BMS circuit design 200 $7,000.00 $0.00 $7,000.00

PCB layout 40 $1,400.00 $0.00 $1,400.00

Device Assembly 90 $3,150.00 $576.10 $3726.10

Testing/Debugging 100 $3,500.00 $0.00 $3,500.00

Lecture/Group Meetings 230 $8,050.00 $0.00 $8,050.00

Total Labor 740 $25,900.00

Total Parts $576.10

Project Total $26,476.10


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microcontroller due to extra memory requirements. Per the requirements of the American Solar

Challenge regulations, the completed BMS will be an active protection system designed to

continually monitor over-voltage, under-voltage, over-current, and over-temperature of the

Lithium based battery packs [12]. The major milestones set are to have a working prototype built

and tested by mid October, fabrication and installation of BMS system by mid November, and a

fully tested and functioning system by the week of December 9th, 2011.


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9. References

[1] J. Durham, N. Murdaugh, D. Trawick, Battery Monitoring System for a Solar Powered

Racer, May, 2011. [Online]. Available:

http://www.ece.gatech.edu/academic/courses/ece4007/11spring/ECE4007L01/ws4/deliverables.h

tml[Accessed Sep. 18, 2011].

[2] A. Bibonge, Lithium-ion batteries and their use, Georgia Institute of Technology,

Atlanta, Georgia, 7 Sept. 2011.

[3] D. Christopher, LTC6802 battery stack monitor, Georgia Institute of Technology,

Atlanta, Georgia, 7 Sept. 2011.

[4] T. Tsegha, Using power MOSFETs as circuit breakers in battery charging applications,

Georgia Institute of Technology, Atlanta, Georgia, 7 Sept. 2011.

[5] M. Slade, Embedded microcontrollers used in technological devices, Georgia Institute

of Technology, Atlanta, Georgia, 7 Sept. 2011.

[6] D. Martin, Driving field effect transistors with various gate drivers, Georgia Institute of

Technology, Atlanta, Georgia, 7 Sept. 2011.

[7] All Battery, Detailed description of LiFePO4 38120S battery,stores.headway-

headquarters.com, 2011. [Online]. Available: http://stores.headway-headquarters.com/-strse-

1/Headway,-batteries,-EV,-solar/Detail.bok. [Accessed Feb. 4th, 2011].

[8] Micorchip, PIC24F16KA102, 2011. [Online]. Available:

http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en539800 [Accessed Sept.

15, 2011].

[9] IXYS, GigaMOS Power MOSFET IXFK230N20T datasheet, 2009.

[10] Linear Technology, Multicell Battery Stack Monitor LTC 68002 datasheet, 2007.

[11] National Semiconductor, Precision Centigrade Temperature Sensors LM35 datasheet,

2000.
http://www.ece.gatech.edu/academic/courses/ece4007/11spring/ECE4007L01/ws4/deliverables.htmlhttp://www.ece.gatech.edu/academic/courses/ece4007/11spring/ECE4007L01/ws4/deliverables.htmlhttp://www.ece.gatech.edu/academic/courses/ece4007/11spring/ECE4007L01/ws4/deliverables.htmlhttp://stores.headway-headquarters.com/-strse-1/Headway,-batteries,-EV,-solar/Detail.bokhttp://stores.headway-headquarters.com/-strse-1/Headway,-batteries,-EV,-solar/Detail.bokhttp://stores.headway-headquarters.com/-strse-1/Headway,-batteries,-EV,-solar/Detail.bokhttp://stores.headway-headquarters.com/-strse-1/Headway,-batteries,-EV,-solar/Detail.bokhttp://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en024610http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en024610http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en024610http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en024610http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en024610http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en024610http://stores.headway-headquarters.com/-strse-1/Headway,-batteries,-EV,-solar/Detail.bokhttp://stores.headway-headquarters.com/-strse-1/Headway,-batteries,-EV,-solar/Detail.bokhttp://www.ece.gatech.edu/academic/courses/ece4007/11spring/ECE4007L01/ws4/deliverables.htmlhttp://www.ece.gatech.edu/academic/courses/ece4007/11spring/ECE4007L01/ws4/deliverables.html


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[12] 2012 American Solar ChallengeGeneral Regulations, September. 2010. [Online].

Available:http://americansolarchallenge.org/tech/tech-center-2012/regulations/. [Accessed Sept.

5th, 2011].

[13] Zero Emissions Vehicles Australia, TS90 Fail Safe Battery Management System

zeva.com.au, 2011. [Online]. Available: http://zeva.com.au/store/datasheets/TS90_BMS.pdf

[Accessed Feb 14, 2011].
http://americansolarchallenge.org/tech/tech-center-2012/regulations/http://americansolarchallenge.org/tech/tech-center-2012/regulations/http://americansolarchallenge.org/tech/tech-center-2012/regulations/https://zeva.com.au/store/datasheets/TS90_BMS.pdfhttps://zeva.com.au/store/datasheets/TS90_BMS.pdfhttps://zeva.com.au/store/datasheets/TS90_BMS.pdfhttps://zeva.com.au/store/datasheets/TS90_BMS.pdfhttp://americansolarchallenge.org/tech/tech-center-2012/regulations/


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Appendix A


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