Hi Blooper and
to the forum.
It sounds like your controller has been set for a 36V battery instead of 48V, and the default overvoltage protection value for the 36V battery is typically set at 52V.
Unfortunately, the voltage of a fully charged 48V battery is likely to be 54~58V, which is 2~6V too high for the controller to work on the 36V setting.
The controller's "Nominal battery voltage (V)" setting will need to be reset to 48V using the USB programming lead and the
vector controller programming software. If it was an MP5
(and you had the Bluetooth dongle and suitable Android phone) you could download
the GoldenMotor App and reset the voltage setting in the controller via Bluetooth.
Whereabouts in the UK are you located, and where did you purchase the bike from?
Alan