How to Connect 4 12V Batteries to Make 24V

When setting up a 24V battery system using 12V batteries, there are two primary methods:

  • Connecting the batteries in series first
  • Connecting the batteries in parallel first

Understanding the differences between these approaches and how to execute them correctly is crucial for maintaining the safety and efficiency of your battery system.

In this article, I will discuss both methods and guide you through connecting 4 12V batteries to create a 24V system.

Interested in reading my expert advice on the best Lithium batteries? Read my article here.

Connecting Series First


  • Simplicity: Connecting batteries in series is a simple process involving fewer connections than parallel connections.


  • Imbalanced Discharge: In series connections, any imbalances in the battery state of charge can lead to uneven discharging, potentially affecting the overall battery lifespan.

To connect four 12V, 100Ah batteries to make 24 Volts, we first connect two batteries in series.

If we connect two batteries in series, we become two sets of 24V, 100Ah batteries.

Series connection first to make two sets of 24v 100ah

Now we need to connect these two sets of 24V 100Ah batteries in parallel to become 24V 200Ah.

Series connection first, then parallel to make 24v 200ah

Connecting Parallel First


  • Balanced Discharge: Parallel connections help to distribute the load evenly across the batteries, leading to more balanced discharging and potentially longer battery life.


  • Complexity: Connecting batteries in parallel first involves more connections than series connections, making the process more complex and time-consuming.

In this system, we will connect the batteries in parallel first. We can do this by creating two sets of batteries and connecting the positives and negatives.

Parallel first to make 12v 200ah batteries

We will then series connect these two battery sets to get 24V, 200Ah.

parallel first, then series to make 200ah 24v
 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! 



Both methods of connecting 12V batteries to create a 24V system have pros and cons. It is up to you which one you prefer.

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9 thoughts on “How to Connect 4 12V Batteries to Make 24V”

  1. I like the parallel series connection would be great if you could post a diagram connected to the charge controller, then to the inverter


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