One of my bikes has a 12volt system. After a recent ride while cleaning it, I heard the battery bubbling like it was on charge. I assumed the regulator was over charging it, so put the voltmeter across the terminals, started it up revved it and got around 14.8 - 15.1 volts with the lights off. That seems OK to me. [?] The thing is, I took the battery off and three days later its still bubbling, any ideas, is it an internal fault? It seems OK otherwise.
Cheers