Series vs Parallel: Understanding battery connections in one article
Battery connections can be made in two fundamental ways: series and parallel. These methods refer to how multiple battery cells are connected to meet the power requirements of various devices. Typically, a single battery cell cannot fulfill these needs. For example, plb Battery’s 26650 LiFePO4 cell has a voltage of only 3.2V, which is insufficient for devices requiring higher voltage or energy storage. Therefore, to increase both voltage and capacity, cells are often connected in series or parallel. Let’s break down the differences between these two configurations.
What are series and parallel connections?
Series connection is the simpler of the two. It involves connecting the positive terminal of one cell to the negative terminal of another. To connect additional cells in series, continue connecting the positive terminal of the second cell to the negative terminal of the third, and so on. This process increases the overall voltage of the battery pack.
Parallel connection, on the other hand, involves connecting the positive terminals of all the cells together and the negative terminals together as well. If you want to add more cells in parallel, connect the positive terminal of the third cell to the positive terminals of the others, and do the same with the negative terminals. This configuration increases the overall capacity of the battery pack without changing the voltage.
In practical applications, batteries are often connected using both series and parallel configurations. This combined setup is necessary because relying solely on one method may not meet the power requirements. By combining series and parallel connections, battery packs can be customized to deliver the desired voltage and capacity.
For simplicity, battery packs are labeled with abbreviations : “S” for series and “P” for parallel. For example, if a battery pack consists of 20 cells, with 4 cells in series and 5 cells in parallel, it would be labeled “4S5P” or “5P4S.”
Advantages and disadvantages of series and parallel connections
The main function of series connection is to increase the voltage while keeping the capacity constant. For instance, if you connect eight 3.2V, 3000mAh LiFePO4 26650 cells in series, the result will be a 25.6V 3000mAh battery pack.
Advantages of series connection:
Increases the voltage to meet the demands of systems requiring 12V, 24V, or 48V.
Devices with voltage-specific requirements function more reliably with higher voltage.
Lower current improves the safety of the battery pack.
Disadvantages of series connection:
If one cell becomes damaged, the entire battery pack may be affected, potentially disrupting the power supply.
The main function of parallel connection is to increase the capacity while maintaining the same voltage. For example, if you connect eight 3.2V, 3000mAh LiFePO4 26650 cells in parallel, the result will be a 3.2V 24Ah battery pack.
Advantages of parallel connection:
Increases the overall capacity, allowing the battery pack to store more energy.
Discharge is safer since a fault in one cell won’t severely affect the entire circuit.
Disadvantages of parallel connection:
Cells must be well-matched in terms of performance. Significant differences between cells can reduce the overall efficiency of the battery pack.
Series and parallel battery connections each offer unique benefits and drawbacks, and choosing the right configuration depends on the specific requirements of your device or application. Series connections are ideal for increasing voltage, making them suitable for high-voltage devices. Parallel connections, on the other hand, increase the battery’s capacity, making them perfect for applications requiring longer runtimes or greater energy storage.
In most cases, a combination of both series and parallel configurations is used to create a powerful, stable battery pack with the necessary voltage and capacity. By understanding the principles behind series and parallel connections, you can design and assemble battery packs that are both safe and reliable.