Hey guys sorry have another newb question, sorry if it's been answered before I can't seem to find exactly what I'm looking for. On my 92 tw i can't seem to get the battery to stay charged, I have bought two new ones just in case and they both don't hold the charge. I know it has something to do with the bike and what makes me think that is because on my dad's 91 tw if the battery is out the lights with still turn on once the bike is started. But on mine if I take the battery out and start it the lights don't turn on like his. So that makes me think it's the same reason my battery isn't staying charged. Does a bike have something like an alternator like a car?? Thanks for the help guys!