The mcc board looks like this, with associated LCD and rotary encoder.

The PCB has provision for switchign th echarger on and off. That snot used, the charger used can do that.

Its powered from a 12V plugpack sharing a switched power socket with the charger 60V power supply.  Coming in board lower. There is a 12V to 5V smps in the board centre.

There is a esp32 module and a microsdcard socket. Remove the lowest pullup (as pictured) on the sdcard module or the esp32 wont boot.

20char x 4 line lcd with an I2C backpack, and a rotary encoder for a primitive UI. 

The LCD allows me to see individual battery voltage and balance state, charger voltage and current, charge state and battery temperature

 So all this oard does is to display whats going on. Its not on the mower, rather next to the charger.