I’ve got 16 modules out of a Model S battery pack. These modules run at 24V, so I’m the plan is to series two then parallel eight in order to achieve a 48V system voltage. The plan is to use a multiplus-II in a grid connected scenario so I can sell power back to the grid / offset my usage.
I’m just wondering if anyone has any recommendations on BMSes that I can get to make this all work. I need cell level balancing and also safety shutdown (temperature, over charge / over discharge etc).
There appear to be two main options. The first is a DIY one - GitHub - collin80/TeslaBMS this uses the onboard Tesla battery board to gauge charge / temperatures fault states. This is my preferred option as it uses the onboard mechanisms which means I don’t have to replace anything. The downside to this is that I’ll have to come up with my own design for contractors, pre-charging etc. The victim will to run in open-loop voltage control mode. It cannot communicate with the BMS. Fault communication to the Victron will be via a single pin which is pulled high if a fault of any kind (temp/overcharge/undercharge) is detected.
The second option is something like BPath or VeroBMS. I’m leaning more towards the BPath: Battery module controller XL - BPath Energy
This appears to be a complete turnkey solution that can plug into a victron and communicate via CAN. It has built in contactors/shunt etc to pass on to the Victron via CAN. The downsides is it’s expensive at 1700 EUR and also its proprietary so if some component breaks it’s not easy to figure out what went wrong and fix it.
There are other options that are not as turnkey - for eg VeroBMS, SimpBMS etc but that sounds like too much work for not much benefit.
Just wanted to ask if anyone else has any ideas or comments on this.
I’d love to hear