I thought the same thing went out and purchased a new one today, but it did not work, , so have it on the charger all night, but I did check voltage and it was over 12 volt... Crazy thing was, my 12 volt died after sitting parked for about a month, I put my 12 volt charger on it, next day got it started and drove around doing several projects. when I pulled it back in my shop to charge the main battery it just would not go up, hence my thoughts on a new battery, I am going to try it again tomorrow and see if it will charge my main battery.. Sort of scary, its not good for more than 40-45 miles now as it is, but if I can not get her charged... Not going to be worth much at all..ratt finks... (smile)