To connect 6 12V batteries to create a 24V system, you’ll need to arrange them in a series-parallel configuration.
(Scroll down for diagrams)
Here’s how to do it:
- Divide the six batteries into three groups of two batteries each.
- Connect the batteries in each group in series: Connect the negative terminal of Battery 1 to the positive terminal of Battery 2.
- Repeat step 2 for the second and third groups of batteries.
- Now, you have three sets of 24V (two 12V batteries connected in series).
- Connect the three sets in parallel: Connect the positive terminals of sets 1,2, and 3 together. Connect the negative terminal of sets 1,2, and 3.
Now, you have a 24V battery system with the capacity of three batteries combined. The positive and negative terminals for your 24V system will be the positive from the first set and the negative from the third set.
Divide the six batteries into three groups of two batteries each
Make three pairs of two batteries. The positive and negative terminals should face each other. You now have three sets of two batteries.
Connect the two sets of batteries in series
Now we will connect the two batteries in series to make 24V. We do the same with sets two and three. Now we have three sets of 24V batteries.
A series connection increases the voltage. If we connect two 12V batteries in series we get 24V.
Connect the three sets in parallel
Lastly, we make the parallel connections between the three sets of 24V. Parallel increases the capacity (Ah) of the battery without increasing the voltage. The resulting battery will be 24V, 300Ah.
It is essential to have the negative and positive terminal from another battery for current sharing. If you were to put the main positive terminal on battery 5, then batteries 5 and 6 will work harder than batteries 1 and 2. Therefore the positive terminal should be connected to battery 1 and the negative to battery 6.
You need to fuse the positive lead with an appropriate fuse. Please read my article on how to determine fuse size here.If you connect batteries in series, ensure they are at the same state of charge! Always use safety goggles and insulated tools when working with batteries!
It’s easy to make a 24V battery out of 6 12V batteries as long as you follow these steps. Make sure you wear eye protection when working with batteries.