ok i am an electronics engineer,had an erbrauer 14.4v 1.5ah drill for 5 years,with pretty heavy use,left battery charging for a few days,i,d forgot about it,next time i tried to charge no red light,,ok so i had the green,so transformer ok,,i also tested it,,had to file a notch in an old screwdriver to remove base as screws non tamper,tested everything,,all appeared fine,,small black block with red lever??inserted battery,pressed red lever with a pencil,,red light on/charging???was going to make permanent solder joint beneath red lever,,yet as i de-soldered unit ,it corrected itself?so re-fixed red lever 3 pronged switch...either this is a type on thermal device i am unfamiliar with,, or this is a memory type switch, 500 charges then dead ??either way both batterys now at peak performance,,if this helps someone it was worth the time to write bry
brian electronics, March 2012