Here's the deal with amps, the more amps that a charger has, the faster the charger will charge your batteries. However, it really is a balance between getting enough amps that your battery charger charges quickly, and not putting too many amps on the batteries so that the batteries have a shorter life span. So the moral of the story is, more is not always better with respect to amps. With that said, for a 48 volt golf cart, 13 amps has been found to be the right balance between charging speed and long-term battery stress. For a 36 volt battery charger, 21 amps is standard. You'll want to avoid purchasing a charger with low amperage (2-5 amps) as it will take forever to charge your batteries.