Thanks! My battery is 3 years old. I have a Tmax and the pro performance kit installed. My battery dies if it's been setting for a week. I can't use a trickle charger because I site my bike in my enclosed trailer that's store in our community boat sheds. I just bought a solar panel I need a plan it wire that up to keep my battery happy or I'll be changing it every 3 years. I hope it's the battery.
These days changing the battery every three years isn't all that unusual. Batteries seemed to last longer ten to fifteen years ago, but the last few I've owned (cars and bike) can't seem to make it past three years even though they are kept fully charged all the time. I'm convinced it has to do with cheapening in the manufacturing process, which has plagued many products.
If you don't ride often enough to keep the battery fully charged, and you can't use a Battery Tender, then I'd suggest you disconnect the battery during long periods of inactivity. You could install a marine battery isolator (disconnect) switch to make it easier to disconnect without removing the seat if you don't mind doing a little basic wiring modification.
Jerry