Lead-Acid Batteries

(Commonly used in cars, trucks, boats, golf carts, forklifts, RV's, solar/wind systems and many other applications)

Voltage of a battery

Lead-acid batteries include AGM, VRLA, Gel Cell and Flooded batteries.  Lead acid batteries are composed of battery cells. Each battery cell is approximately  2 volts.  In most batteries, you can determine the voltage by counting the battery cells. In flooded batteries, each filler cap is a battery cell.  In sealed batteries, the caps are sealed.  A battery with 3 caps is a 6 volt battery. Examples:

6 volt Golf Cart Battery The 3 filling caps are circled	12 volt Sealed Gel Cell Battery The 6 sealed caps are circled

Voltage of a battery system

Now that we know the voltage of the batteries, we can now determine the voltage of the system. Golf Carts: Count the number of batteries and multiply by the voltage. 6 x 6 volt batteries is a 36 volt system. Other systems: To determine the total voltage of a battery system, you first must determine how the system is connected.  Battery systems are either connected in series or in parallel.  First, observe the connections between the batteries.

• Series connected battery systems are connected from the positive (+) terminal of one battery to the negative (-) terminal of the next battery, or vice-versa.  To get the total voltage of a series connected battery system, multiply the number of batteries by the voltage. 3 x 12 volt batteries connected in series is a 36 volt system. 

  

• Parallel connected battery systems are connected from the positive (+) terminal of one battery to the positive (+) terminal of next battery as well as the negative (-) terminal of the same battery to the the negative (-) terminal of next battery.  The total voltage of a parallel connected battery system is the voltage of one battery. 3 x 12 volt batteries connected in parallel is a 12 volt battery system.