Having problems with 12V system. I learnt the i needed to charge the leisure battery so i changed the battery with a just charged spare . this was a week ago. got motorhome out of storage and on a pitch just for saturday night to try things out. during the day and evening the battery charge indcator went from fully charged to not alot.all the lights and pump gradually stopped .the recent changed battery is only 2 years old and was fully charged .i thought that when on hook up the leisure battrey was being charged.is there a problem with the in built charging unit .when i put the van back into storage the next day the short drive seemed to put some charge into the leisure battery , does driving the van also provide a charge to the leisure battery. when i swopped the battery last week i touched the - terminal with the +lead and got a small spark would this have caused the problem.help would be much appreciated . .