Electric Vehicles and Batteries

My interest in EVs began while teaching energy at the Air Force Academy.  Several electric off-road vehicles purchased by the military special forces were given to the Academy.  The vehicles had been designed and built by a Monument research company called American Electric Vehicles.  When they were given to the Academy, there had been somewhat abused by the special forces and none were in useable condition. 

With funding through an energy grant, and with the help of two years worth of senior design teams, one of the vehicles was made to be functional.  The original electronics and batteries were mostly shot so the senior design teams rebuilt a new set of electronics and acquired a brand new set of lithium-ion iron phosphate batteries.  (LiFePo). 

in 2015, the vehicle was gifted to UCCS as the Air Force Academy was no longer interested in EVs. 

The details of the rebuilt vehicle are:

BMS — We used the "mini-BMS" system.  The mini-BMS used a small monitor board on every individual battery and had the capability of shunting current if a preset threshold was reached.  A loop was created across all of the 96 batteries and if all was good, a "go ahead" signal was generated by a central controller. 

Voltage — The overall battery voltage varied from about 240 – 340 vdc as the system was charged and discharged.  A current counting system was used to estimate remaining capacity.