Well here goes. Last night I needed a boost, problem was I was going for a ride with a HD driver. He got a kick out of having to boost a BMW. The battery, I think, is original, 1999. I am going out to buy one in a couple hours. It will not be from BMW, but, a local bike store. Is there anything I should be aware of before I buy? The charging system is at 13.4 volts at idle, 13.8-9 when reved a bit.