I believe the secret is the tender when not in use, especially as the battery ages.
Keeping a full charge on them is certainly the best way to get the most life out of 'em. I must admit I wasn't (still not) religious about plugging in all the time. I usually get home from a ride and figure I will be riding again soon so I don't plug it in and then it rains for weeks and at some point I want to ride or I move the bike and
I just plugged it in the other day and it wouldn't even light the radio screen, it only took two nights to charge up. Still it ain't good to draw them down that low I know, but these damn '06 bikes have a hell of a drain from the junk on them.
Maybe the nanner isn't so bad