If it were the battery, it would have to be so bad that it wouldn't start the bike.
While running, the alternator charges the battery and runs the electronics.
The battery isn't out of the loop, but its just sitting there absorbing any sudden spike in the system. Be it a drop in voltage or a rise.
My alternator puts out 14.4 v at idle with head lights, tail lights and what ever else.Thats a load of 3 amps or more.