The vast majority of golf cart battery bank wiring is done in a “series” circuit. To wire in a series circuit means to connect multiple batteries in such a manner that the entire battery bank acts as a single battery, but with the total sum of the voltages of each individual battery. A common example is that six 6 volt batteries wired in a series circuit will act as a single 36 volt battery.
Before proceeding with this discussion, you must first know that common battery banks in golf carts, being 36 volt and 48 volt versions, contain a significant amount of combined current. If directly exposed to high current (amperage), it could cause serious injury or death. Please always exercise the utmost caution when working with power circuits of this nature. Remove all rings or jewelry from your hands and arms, and use insulated tools If possible. If you are unsure about making power connections with this much potential current, please stop and do some research with trained golf cart professionals before proceeding.
Two simple statements govern the rules for series versus parallel golf cart battery bank wiring. In a series circuit, the current through each of the components (batteries) is the same, and the voltage across the circuit is the sum of the voltages across each component. In a parallel circuit, the voltage across each of the components is the same, and the total current is the sum of the currents through each component. Parallel wiring of a golf cart battery bank is not very common.
For the purpose of golf cart battery bank wiring in a series circuit, the dislike terminals are connected in order. To connect six 6 volt batteries together in series, you start with the main positive (+) or main negative (-) terminal of the entire battery bank. For this example, let’s start with the golf cart battery bank main positive terminal and connect six 6 volt batteries in series to form a 36 volt bank.
The golf cart battery bank wiring configuration shown below is very commonly used in the E-Z-GO TXT golf car product line as well as many other vehicles. The top of this illustration is oriented to face the front of the golf cart. In which case, the top right battery in our illustration represents the front passenger’s side battery. The positive on this battery will be the main positive for the entire battery bank. The negative is then connected to the positive on the next battery. Connect negative to positive all the way throughout the circuit until you arrive at the main negative for the battery bank. If connected properly in a series circuit as shown, you should be able to test across the battery bank main positive and main negative terminals with a voltmeter and get a reading equal to the sum of each battery. In this example, your reading should equal 36 volts (6×6 = 36).
As previously mentioned, when wired in series, the batteries combine their voltage to effectively make a higher voltage golf cart battery bank. Even though their combined voltage is now equivalent to 36 volts, the current or amperage through the batteries which comprise the bank is unchanged. In a series circuit, such as our battery bank example, every battery or component within the circuit must function properly for the circuit to work. If you have a single bad battery, your golf cart may not work due to low overall voltage of the bank due to the bad battery. Further, if a battery cable connecting the individual batteries breaks or is disconnected, the circuit is not complete and will not allow the golf cart to move due to low voltage.
For the purpose of this discussion, it is irrelevant if your golf cart has a DC or AC power system, a series wound motor or a separately excited version. The power supplied to the controller or inverter is most commonly supplied from a golf cart battery bank using individual batteries wired in series to provide a higher useable voltage.
A 48 volt golf cart battery bank wired in a series circuit is also very common in this industry. However, there are several combinations of individual battery voltages which can provide 48 volts. These combinations include the following:
- 48 volts (six 8 volt batteries connected in series)
- 48 volts (eight 6 volt batteries connected in series)
- 48 volts (four 12 volt batteries connected in series)
Before connecting any of the main power leads, positive or negative, be sure to always test across the main battery bank terminals with a voltmeter to ensure you have wired your golf cart battery bank correctly and that the voltage equals what you expected (i.e. the sum of the individual batteries should equal the total bank voltage). Be safe!
By Michael Williams