BMS discharge in series - Regen in parallel?

I’m wanting to make a few modular 6S5P liion packs to power a couple different builds. For my longboard I’d like to run 2 packs in series (12s5p) but charge on-board in parallel (6S10P). I’ve got the wiring of this figured out with a way to isolate the charger port so I don’t create a short but I’m not sure if I can configure a the VESC so that I can still use Regen in this configuration. So I have a couple questions for the experts here…

  1. Can the VESC output and Regen at different voltages?
  2. Can I just pump back a higher voltage to the BMS during Regen?
  3. Do I need separate charge port on the BMS and use a stepdown to get to the proper 25v?
  4. Anyone else doing this that has some tips/tricks?

The cells in using are 30Q and the BMS I’m considering is this one:

Thanks in advance for your help!

The VESC draws power and throws power back from regen through the same wires. I don’t see how this is possible without some kind of intelligent switching circuit that likely doesn’t exist.


You are over complicating things. Use XT connectors to wire them into go between parallell and serial “mode”. Youll endup with 2 XT connectors and one charge port. And an on/off Button.


Thanks that makes sense. Not sure why I was under the impression they were separate connections but that answers my question on separate charge port vs integrated on the BMS.

Maybe I’ll just make life easier and get a 12s and 6s BMS to attach to the configurable battery based on application and gaurd each cell pack with a 80A fuse in case something shorts while mixing up the packs.

Was planning to use 2 Bestech BMS but has anyone used these? I like that they are already enclosed. BMS 12S 60A:

I’ll try and make a schematic tonight so it’s more clear what my plan (now) is… Is it best to post that here? Or is there already a “Please check my wiring to help prevent fires” section that I should post in?