Erato/Sakura moped controller

View into space under moped seat box where batteries and controller (removed) live.

Top of board, dominated by heat sink.

Controller end of board. PIC16F72 that is the smarts. Hall sensor inputs in foreground.

Bottom of board showing 4 screws that mount heatsink

What does that unused connector labelled PWD, VLD, XIN, XHD do, I wonder?

ONly board ID: "BLC3000" REV1, which I guess is something like 'Brushless Controller, 3kW" (It puts out 2.5kW with a 48Vbattery)

Unused 'SPD' (Speed?) connector.