I bought an AGM battery when I got the Intestate in 2007, and it was still in it in 2013 when I sold it. I put a tickle charger on in the spring just before getting the bike out. I never took the battery out in the winter, and the bike was stored cold. I never had a problem with the battery starting the bike in the extreme cold either. (one time -10) After all that, I won't have any other. I can't remember the brand, but, bought it at autozone
