Batteries; #1 should never be stored in unfully charged state, if they are in a month or so they begin to sulfate. #2 The storeing of batteries on concrete This was back when the batteries had a wooden case. Concrete zapped the moisture from the wood and it rotted; We must remember the battery is only a storage unit. it stores electrons + and -. like a bucket stores water. OR maybe BEER. and we all like fresh stuff. The internal resistance of battery is near .007. which means it will go dead if left without being in a fully charged or unused.: