So I have built an electric vehicle that uses battery packs from a BMW 330e. Each pack is made of 6 x 16s modules, making 96s. 1 pack is 9kwh the other is 12kwh and they are wired in parallel.
Each 16s module has a BMS module attached which has cell taps. I can talk over can to each module to get voltages though i’ve not got the balancing working yet. One of the modules is water damaged and another is telling fibs, so i’m looking at possible swapping them for a DIYBMS install as they’re hard to get hold.
Could i replace each bmw board with a DIYBMS board and add a controller to read all the voltages, and also balance the cells from time to time. I don’t mind if the balance has to be done during downtime as it were as it doesn’t often need doing.
I need to read the voltages into my arduino that controls the charger so i wonder is there a way of reading and controlling diybms other than the web interface ? If i want to control the pack modules in this way (over i2c) do i need the controller ?
all assistance much appreciated