1. Solar Jackets’ Racer Battery Management System(BMS) Ali Bibonge Daniel Christopher Paul Martin Mark Slade Taverishima Tsegha
December 7th, 2011

2. Battery monitoring system for a solar powered race car
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

3. 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

4. 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

5. BMS System Flow Chart

6. Prototyping

7. Prototyping

8. Testing
Something here...

9. Demonstration of Temperature Sensor

10. Demonstration of Current Sensor

11. 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

12. Total amount spent is approximately $400
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

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

14. Recommended Future Work
LTC programming
Incorporating the electromechanical relay into the battery box
RS-485 programming
Mounting PCB components

15. Questions?