The original battery on my '04 RC died a couple of years ago, and I replaced it with an new (expensive) one. For several reasons, the bike hasn't been ridden since then, but it's been in the garage with a Battery Tender connected. Yesterday when I attempted to start it, which I've done every couple of months, it turned over two or three times and then quit. Any theories? The bike is very low mileage (4500) and the garage is tight and dry.