I have an new unused JBD AP20S004 13-20 cell BMS for sale - R2200.
It has bluetooth and RS485 connectivity and come with the RS485 to USB cable.
This BMS can connect to Victron’s ESS systen using my driver and you can set it up using tha bluetooth app from your phone.
More details on the model here
Still available. I can courier it to most major cities in SA for free.
The 13s - 20s makes the BMS very flexable. As it is fully configurable, you could in future handle cells with other voltages than what is currently the in use (3.2V or 3.7V lithiums).
So with this BMS you can create a 48V battery from cells that run at 2.5V when such cells are intruduced.
And 13s will give you a 48V battery using 3.7V lithiums.