openinverter forum

Would it be possible to use 2 BMW 12kWh batterypacks in parallell?

Tomas wrote: ↑Tue Mar 14, 2023 12:55 am Would it be possible to use 2 BMW 12kWh batterypacks in parallell?

Why not? Or perhaps, why not use three for high power and better range?
You will have to decide on how to connect on individual cell/module/pack level. I recommend you draw some diagrams so you can visualize where to put the fuses or pack disconnects...

This topic came up on another thread after I asked a question about running more than 6 modules in series for higher voltage. Some users are doing exactly what you are proposing, but the issue is tied to the BMW BMS configuration - you'll probably want to use SimpBMS on these to leverage BMW's factory BMS boards (search this out). The BMS is designed to work with 6 distinct CAN addresses - I believe that the packs can be jumpered to listen on a specific address, but you are limited to 6 choices (Take a look at YouTube user "Good Enuff Garage" - he did several videos on this IIRC). Essentially you will probably need to use a CAN bridge with offset addresses. This should give you an idea of what to search on - I think more extensive answers probably lie in other threads. Hopefully this is enough to get you to the next level.

> Essentially you will probably need to use a CAN bridge with offset addresses

or use separate can channels on a Teensy i guess would work.

I currently am running 18 modules 6s3p paralleled at the cell level via cell taps and module level, each parallel set of 3 modules share 1 bms, currently working on designing some simple plugin pcbs with fuseable links, but I’ve run without them for 2 years, probably time to do something about that right….

When I built this I was completely reliant on existing code, I would probably follow a different route now…