1100 boxer cup charging

[T900]

my mate has an 1100 boxer cup and battery keeps going flat, i am going to look at it tomorrow for him. are there any known faults with charging system or anything that may drain the battery.
thanks

 

[Stewart H]

Take a meter and check the voltage with the engine running, it should be around 13.8-14 volts, these bikes are pretty heavy on batteries. Alarms etc provide constant drain.

Stewart