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

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

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

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

Conclusion
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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