Solar Jackets’ Racer Battery Monitoring System(BMS) Ali Bibonge Daniel Christopher Paul Martin Mark Slade Taverishima Tsegha October 26 th, 2011

2 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  Cost: $1200

3 What Does the BMS Do?  It Monitors:  Li-ion Cell Over/Under Voltages  Li-ion Cell Over Current  Battery Pack Over Temperature  Transmits/Receives acquired data via RS-485 to racer systems

4 BMS Current Design Status  Prototype able to:  Measure module current  Measure module temperature  Electrically isolate the Li-ion cells

5 Data Collected by the BMS  Data structure including :  Voltage data (individual cells/module)  Module temperature  Module current

6 BMS System Flow Chart

7 System Development Problems  Conversion of existing PIC18 code to PIC24  Cost of electro-mechanical relay  $ per relay  Space limitations in the battery module

8 Battery Box Limitations

9 Another View

10 Battery Module and Cell Thresholds

11 Temperature Green Zone Test Picture

12 Temperature Red Zone Test Picture

13 Project Milestones  November 4: Working voltage sensing feature with PIC24  November 9: Testing electromechanical relay  November 16: Fabrication and assembly  December 9: Final presentation

14 Questions?