What is Battery Balancing in Energy Storage?

Battery balancing is a vital process in energy storage systems (ESS) that ensures uniform voltage or state of charge (SOC) across individual battery cells within a battery pack. Proper balancing prevents overcharging or over-discharging of cells, which can lead to decreased performance, shortened lifespan, and potential safety hazards.

Battery balancing is primarily classified into two methods: active and passive.

Types of Battery Balancing: Active vs Passive

Passive Balancing: This method dissipates excess energy from higher-charged cells as heat through resistors. It is an affordable and straightforward approach commonly used in lower-cost ESS or non-critical applications.

Active Balancing: In contrast, active balancing transfers excess charge from higher-charged cells to lower-charged ones using capacitors, inductors, or converters. This method redistributes energy dynamically, ensuring optimal SOC across all cells with minimal energy loss, making it ideal for high-performance or long-duration energy storage systems.

Features of Active and Passive Balancing Systems

Passive Balancing Features:

• Lower cost and circuit complexity

• Energy waste in the form of heat

• Easier implementation in compact ESS designs

• Commonly integrated into Battery Management Systems (BMS) for small-scale applications

Active Balancing Features:

• Higher energy efficiency due to effective charge transfer

• Better cell health, leading to a longer battery lifespan

• More complex and expensive circuits

• Ideal for large-scale or high-demand ESS installations

Applications of Active vs Passive Balancing

Passive Balancing:

• Residential ESS (5–30kWh)

• Consumer electronics

• Backup power systems with low cycling requirements

Active Balancing:

• Commercial & industrial ESS (100–215kWh and above)

• Electric vehicles and renewable energy storage systems

• Containerized and utility-scale storage systems

• Systems with frequent charge/discharge cycles

Price of Battery Balancing Systems

The cost difference between active and passive balancing systems can be significant. Passive balancing is more economical due to its simple design, while active balancing requires advanced components and control algorithms, which increases initial costs.

Pricing is generally quoted based on international trade terms such as EXW, FOB, or CIF. For a precise quotation tailored to specific energy storage projects, direct consultation with the supplier is recommended.

How to Select Battery Balancing for Your Project?

• Evaluate the system’s voltage range, cycling frequency, and temperature sensitivity.

• Passive balancing is suitable for cost-sensitive or compact systems with fewer cycles.

• Active balancing is recommended for large-scale, high-performance, or long-lifespan systems, offering a better return on investment (ROI).

• Ensure compatibility with lithium iron phosphate (LFP) cells and the integration of balancing circuits with the BMS.

How Long Does Battery Balancing Last?

Battery balancing systems typically last as long as the BMS, which is designed to match the battery’s lifecycle. This can range from 5 to 15 years depending on the application. Active balancing may extend battery life by 10–20%, thanks to improved charge distribution and cell protection.

Dagong ESS: A Trusted Supplier of Battery Balancing Systems

Dagong ESS is a leading manufacturer of advanced energy storage systems, offering both active and passive battery balancing technologies. With a focus on high-quality lithium iron phosphate (LFP) battery solutions, Dagong ESS provides the following products:

• Residential ESS (5–80kWh)

• C&I ESS Cabinets (100–215kWh)

• Integrated ESS + EV Charging Stations

• Air-Cooled and Liquid-Cooled Systems

Dagong ESS is committed to delivering customized solutions that meet diverse project demands globally, ensuring optimal performance and reliability.

For more information or to request a personalized quote, contact Dagong ESS at:
📧 sales@dagongess.com
🌐 Visit: www.dagongess.com