Gas engines or electric motors power most golf carts. Gas engines require at least one battery to power the starter motor and accessories such as lights or a horn, while electrically powered carts often have six or more batteries. It is possible to create a 12-volt feed from the batteries with a minimum of electrical and mechanical skill. With a few simple tools, almost anyone can complete the task.
Open the engine compartment. Locate the battery and establish its voltage. The battery should be 12 volts, but it is wise to confirm this. The voltage is printed on the battery casing but may not always be visible. If you cannot find the voltage, set the digital multimeter to read 24 volts DC. Touch the red probe to the positive terminal of the battery and the black probe to the negative terminal. Read the voltage from the meter display. A reading around 10 to 14 volts comes from a 12-volt battery.
Attach terminal connectors to two insulated wires and then connect one wire to each terminal on the battery. Depending on the type of terminal, tighten the terminals using a wrench or screwdriver. Run the wires to the location where you need a 12-volt supply.
Attach a switch to the wire from the positive terminal. This controls the electricity supply and turns it off when the cart is not in use. Do this by cutting the wire at a convenient point and connecting the switch between the two cut ends.
Open the battery or motor compartment. Locate the batteries and count them. Most carts have six or eight 6-volt batteries. Look on the battery casings to find details of the voltage. If the battery casing fails to identify the voltage, test the battery as detailed in Step 1 of Section 1.
Establish the number of batteries required to produce a 12-volt supply. Batteries linked in series have a cumulative voltage, so divide 12 by the voltage of a single battery to determine how many batteries you need. For example, two 6-volt batteries are needed because 12 divided by 6 equals 2. This number of batteries linked together provides a 12-volt power supply.
Attach terminal connectors to two insulated wires and then connect one wire to the unused terminal at one end of the battery chain. Connect the other wire to the opposite polarity terminal of the battery identified in Step 2. In this example, we need two batteries, so connect it to the second battery. Depending on the type of terminal, tighten the terminals using a wrench or screwdriver.
Run the wires to the location where you need a 12-volt supply. Install a switch in the positive wire by cutting it and attaching the ends to either side of a single pole switch. Use this switch to turn off the power when the cart is not in use.
TL;DR (Too Long; Didn't Read)
Keep all wires as short and as thick as possible to reduce resistance and improve performance.
Consider installing a separate 12-volt battery if you make extensive use of 12-volt appliances.
Do not place a high current drain on this type of connection as it may deplete some batteries in your chain more quickly than others.
Batteries are heavy and contain acid. Wear protective clothing and wash skin and clothing immediately if splashed by battery acid.