1) Lift up your golf cart seat to locate the battery compartment.2) Count the number of holes on a battery.Usually 3, 4 or 6 holes3) Multiply the number of holes by 2 to determine the golf cart battery voltage.Each hole/cell is equal to 2 volts4) Multiply the golf cart battery voltage by the total number of golf cart batteries.Batteries for a 36 Volt Golf Cart (6V Batteries)3 holes X 2 volts = 6 volt battery6 volt battery X 6 total batteries = 36 volt systemBatteries for a 48 Volt Golf Cart (8V Batteries)4 holes X 2 volts = 8 volt battery8 volt battery X 6 total batteries = 48 volt system