If the battery does not take a "charge" it is bad and should be replaced. Batteries actually use a chemical reaction inside to produce the volts and amperage by drawing the "water" through fins. You would definetly be better off not messing around with the old battery also make sure when you purchase your new battery you look for a cca rating rather than just a ca rating that means the new battery was tested cold and not at a warmer temperature and will perform better in cold temperatures anyway good luck to you