have an older EZ go cart that was my mother in laws. It worked up until this past summer, when they let it sit for the past 6 months or so. i can't get the charger to come on. I cleaned all the batteries connections and have been charging each battery seperately. I have charged 3 of them and when I put a meter on the set of batteries the most i read is abotu 18-19 volts. The cart will not even make a noise when i turn it on and push the pedal. Any suggestions of what to try. I don't want to buy a new set of batteries until i can verify the cart is working. Thanks!!