Did you happen to check on whether or not you have a light on in the truck? Like inside the truckbox that you cant see? If it stays on constantly you can run down the battery and not know it. I've had that happen in both a car (trunk light) and a truck (sidebox light). Could be why the batterys drained in the first place. You might try banging on the starter with a hammer. Might not work but you'll feel better.