Solar Jackets

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Solar Jackets Racer Battery Management
System(BMS)Ali BibongeDaniel ChristopherPaul
MartinMark SladeTaverishima Tsegha

• December 7th, 2011

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BMS Project Overview

• Battery monitoring system for a solar powered
  race car
• Maintain batteries in a safe to operate and
  efficient state
• For Solar Jackets entry into the American/World
  Solar Challenge
• Overall BMS cost of 1200

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Proposed Design Objectives

• It monitors
• Li-ion cell over/under voltages
• Li-ion cell over current
• Battery pack over temperature
• Electrically isolate the Li-ion cells
• Transmits or receives acquired data via RS-485 to
  racer systems

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Current Design Functionality

• It monitors
• Li-ion cell over current
• Battery pack over temperature
• Electrically isolate the Li-ion cells
• The RS-485 communication component has been
  incorporated into the BMS PCB and is ready for
  programming

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BMS System Flow Chart
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Prototyping
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Prototyping
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Testing
Something here...
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Demonstration of Temperature Sensor
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Demonstration of Current Sensor
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System Development Problems

• Programming of the LTC chip for measuring
  voltages
• The LTC chip has been included on the PCB for
  further programming
• Georgia Tech milling machine is broken

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Final Budget

• Total amount spent is approximately 400
• This covers the electromechanical relay, LM 35
  temperature sensors, ACS758 current sensors, DC
  fuse/fuse holder, and copper bus/connectors

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Battery Module and Cell Thresholds
Green Zone Yellow Zone Red Zone
Temperature lt 40 C 40 C - 45 C gt 45 C
Discharge Current lt 40 A 40 A - 60 A gt 60 A
Charge Current lt 16 A 16 A - 18 A gt 18 A
Voltage (module) 85 V - 103 V 103 V - 105 V gt 105 V
Voltage (Li-ion cell) 2.6 V - 3.3 V 3.3 V - 3.6 V 2.3 V - 2.6 V gt 3.6 V lt 2.3 V
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Recommended Future Work

• LTC programming
• Incorporating the electromechanical relay into
  the battery box
• RS-485 programming
• Mounting PCB components

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• Questions?