Keywords: LiFePO4 battery, series connection, parallel connection, energy storage system, battery configuration
With the growing demand for renewable energy systems and backup power, LiFePO4 (Lithium Iron Phosphate) batteries have become the leading choice for energy storage applications. Their long lifespan, high safety standards, and excellent cycle performance make them ideal for residential, commercial, and industrial energy storage systems. However, a proper understanding of series and parallel connections is essential when designing a LiFePO4 battery system.
What Is a Series Connection?
In a series connection, batteries are connected positive to negative in a chain. This configuration increases the total voltage while keeping the capacity (Ah) unchanged.
For example:
Four 3.2V 100Ah LiFePO4 cells connected in series = 12.8V 100Ah pack.
This setup is suitable for applications that require higher voltage, such as:
- Solar inverters and hybrid solar systems
- Electric vehicles
- Power tools and marine systems
What Is a Parallel Connection?
In a parallel connection, batteries are connected positive to positive and negative to negative. This increases the total capacity while maintaining the same voltage.
Example:
Four 3.2V 100Ah LiFePO4 cells in parallel = 3.2V 400Ah pack.
Parallel configurations are used where long runtime and higher current output are required, such as:
- Backup power systems
- Off-grid solar storage
- Data centers and telecom base stations
Combining Series and Parallel
In practical energy storage systems, engineers often combine both configurations. For example, an 8S2P battery pack has two parallel groups, each containing eight cells in series.
This configuration increases both voltage and capacity to meet large energy demands.
Key Design Considerations
- Always use cells of the same brand, capacity, and state of charge (SOC).
- Install a Battery Management System (BMS) compatible with your setup.
- Ensure all interconnections have low resistance and tight terminals.
- Pre-balance the voltage of all cells before assembling the pack.
Conclusion
Understanding series and parallel connections allows you to tailor your LiFePO4 battery pack for specific energy storage needs. Whether it’s a small residential solar backup or a large commercial ESS, the right configuration ensures safety, efficiency, and long service life.