NWK,
when I had the motorcycles three cruisers, the Yuasa batteries seem to give up ghost at about that time, wasn't really happy with them, so went to AGM batteries ,they lasted about same time, lawn mowers about a year or so, so guess thats about average for these small batteries, unless you want to spend really big bucks, but dont thing they last that much longer to justify expense. I do carry a compact jumper pack now.