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Cars with early BMS

Posted: Thu Oct 30, 2014 8:29 pm
by Grumpy-b
The early versions of the Evie had a BMS that can best be described as a battery killer. This version had to have each cell voltage adjusted individually by using a set of multiturn Pots , by all accounts they were a terror to set up. They drift. And as a result you can get the car shutting down, because the BMS believes a cell has gone low voltage. This part of the system didnt do the active balancing, which was a separate board, with a second cable set. This also had to be manually setup. I have seen a number of these cars having both cut out problems and batteries that are being bled down by the BMS.
Since I now have the spare cable sets , and also new BMS units, I have now worked out a mod to take out the original BMS , add the new one into the spare wheel well, (As per later cars) put in new BMS / Cell cables and re wire a lot of the Curtis controller inputs and outputs. Once this is all done the software in the Curtis controller has to be changed, and I have now modified a version to work with this set up. Hey presto, the cars now have the later BMS, and drive much better with less pack destruction.
The first one took 6 weeks lots of sleepless nights and grey hair to sort out the software issues, but I can now convert a car in about three days. This gives a new lease of life to the early cars, and also allws me to download the BMS data for any future diagnostics.