tell me what your Bionx battery warranty states in document which you got with kit?
my guess is battery electronics /inside battery/ need resetting, .
there must be processor microcontroller most probably PIC type
disconnecting 5V supply to it will reset it.
those 30 charges you mentioned were normal or any abnormallity??
SOC meter showed full charge when battery was full?
of course every BIONX will not power up on just any 36V battery.
battery electronics need to make "handshake" with motor and display on every power up.
Bionx is not analog system. It is similar to Eplus.