Please read these instructions:

Listing is for single unit BMS module for Onewheel GT. Does not work on XRC or any other 63v board. Module is low miles and has been tested before removal. For installation please be sure to plug your controller cables first, xt60 from battery 2nd and balance cables connector last. See 3rd picture for NRF connect pairing instructions. ⚠️Please check your firmware: if you have updated haptic buzz firmware you won't be able to enter factory mode to pair bms to controller.  You woud need to downgrade firmware to 6109  first, then pair bms, then update again (optional) ⚠️ I can guide you how to downgrade firmware if needed but it usually done via st-link, I also offer firmware downgrade service for a fee if you send your controller in. Check out my other listings for more onewheel parts.