I just replaced both batteries on my 2 1/2 year old truck. They both had the little green light still showing. I took it to Wallyworld and they found one of the terminals had broken off and was able to rotate while still attached. This caused the good one to be drained and stressed so much that it was worn out too. No telling how long it had been broken. It never leaked or gave any sign it was broken. But they both still had the little green lights glowing. I replaced them with two $59 Maxx-1 specials and the engine turns over like it is new again. 3 year free replacement on the Wallyworld ones, with 9 year total warranty. I guess we will see. Cant afford the Optimas right now. My divorce attny has all my spare change.