Just wondered others experiences, i know if a vehicle is not used say daily the battery will gradually discharge and best cource is to have a trickle charge set up for that ? but speaking to the trade they recon that if a commercial battery lasts more than 3 years your doing OK? Best batteries life ive always found is the ones that come from new in my toyota hiluxes ? Yes ive made a mistake at times left one on so overnight it run flat in morning? but a quike jumpstart with batterycables soon got it going, oldest one that left me was on a toyota that i sold that was nearly 20 years old with the same battery still on it, who knows how longer it lasted with its new owner ?