I have an Optima battery and it is at least 15 years old. it even sat for 2 years while i redid the truck and with a mild charge it has served me well for the last 3 years. i have read that you can not kill them. when they do go down you have to bring it back to 7.5 volts with a feeder battery then charge it to 12v. i have a maintainer on mine now.
