I have a 12 camry that the battery has gone weak on lately because I don't drive it much. I have been jumping it off when I drive it and then it charges up and starts fine. Yesterday it would not hold a charge so I put my jump starter on it in what I thought was charge mode. When I checked this morning after being hooked up all night the car was still dead and when I disconnected it and then tried to reconnect it and start it the alarm (horn) goes off and the batter is dead as a door nail. So at this point if I try to reconnect the jump starter when I turn the starter to on position the horn on the car goes off. Any ideas?