Hi there, further to what GM has stated on optima batteries. He found connecting straps inside the batteries corroded through possibly from gassing because the batteries have been left on trickle charge or float charge way too long. Optima batteries don't require to be left on charge indefinitely like other batteries do. In fact I only occasionally place my optimas on charge in cars that sit around for weeks or even months at a time. They don't loose charge like other batteries do. Always a good idea to have a battery cut off switch on all old cars. This prevents any battery drain down and also makes the car safer whilst sitting around when not being used. Don't overcharge your optima battery, they don't like it. Regards, Kevin.
