Lately I have been having amazingly weirdly good luck on batteries. Wife's car is over 8 years old and still cranks like new. Tractor is over 11 and is showing signs of "the end is near", but where it is parked is easy to pull the charger/jumper over to start it if(OK, when) it finally gives out. Mower is like 6 or so now. I don't use maintainers constantly but will put the mower on one as spring approaches, and the tractor needs some help if it sits too long (no surprise given the age). My old truck had a slow drain that made it die when it sat, which it often did in recent years but just got replaced with a new truck a year ago, so we'll see how far that one goes...