I think the key to battery longevity, is to keep it on a float charger, no matter what type of battery you have .
If you have a serviceable type battery, checking the electrolyte level regularly (at least once a month, until you see a pattern of how frequently the level goes down), so you don't expose the plates of the battery .
My last Odyssey battery gave me plenty of warning of it's condition .
I had it installed in the oilhead, last January the starter didn't sound quite right after sitting out at work .
I swapped the Odyssey battery for one that I had in the '81 R65, a generic AGM type from Staab
Battery .
http://www.staabbattery.com/product/UB12220-V.htmlI installed the Odyssey in the '81 R65, around September of this year, even with a float charger attached to the battery when the bike was not in use, after sitting at work for 18-20 hours, I started having  slow starter operation, I knew the battery was gone and if I let it go any longer, I'd be sitting somewhere with a dead battery .