Although my current original batter is still cranking fine (5 years now) I know it's just a ticking time bomb waiting to let me down when I least need it to. What replacement battery did you use from the stock one?
Around 4 years ago Amazon had a good deal on Delco batteries... like under $30 good. So I bought one and put it on the shelf for a couple years. After 8 years I started getting cold feet and removed the working stock battery and installed the Delco. Starting my 3rd year on that - after sitting for about 4 months the Wing fired right up last Saturday. I do not even own a trickle charger/maintainer.
I'd say your stock battery has plenty of life left. You gamble with new ones too.
2006 ABS Gold (Built in U.S.A.), Full Mega Mondo Monte, Lots of extras! (3/25/2006) - PROGRESSIVIZED - Full Monte (Wing Ding 29) -WingSoftLarge Complete Seat Modification, Full Mega Mondo Mega Plus Mega Monte. Gold: The color with the most muscle! (Muscle and Fitness Magazine, June 2006, page 48 )