Battery balancing and battery redistribution refer to techniques that improve the available of a with multiple cells (usually in series) and increase each cell's longevity. A battery balancer or battery regulator is an electrical device in a battery pack that performs battery balancing. Balancers are often found in packs for laptop computers, electrical vehicles.
How to balance a battery pack correctly?
needs two key things to balance a battery pack correctly: balancing circuitry and balancing algorithms. While a few methods exist to implement balancing circuitry, they all rely on balancing algorithms to know which cells to balance and when. So far, we have been assuming that the BMS knows the SoC and the amount of energy in each series cell.
What is battery balancing?
Battery balancing equalizes the state of charge (SOC) across all cells in a multi-cell battery pack. This technique maximizes the battery pack's overall capacity and lifespan while ensuring safe operation.
A battery pack is out of balance when any property or state of those cells differs. Imbalanced cells lock away otherwise usable energy and increase battery degradation. Batteries that are out of balance cannot be fully charged or fully discharged, and the imbalance causes cells to wear and degrade at accelerated rates.
What does unbalanced battery pack mean?
This unbalanced pack means that every cycle delivers 10% less than the nameplate capacity, locking away the capacity you paid for and increasing degradation on every cell. The solution is battery balancing, or moving energy between cells to level them at the same SoC.
What is battery imbalance?
Battery imbalance refers to a condition where the battery voltage or state of charge (SoC) varies among the cells or groups within a battery pack. Over time, imbalance creates inconsistency —differences in cell performance—worsening the issue and forming a vicious cycle.
From a State of Charge (SOC) perspective, without balancing, the SOC range is typically limited to 20% to 80% for safety reasons, providing only 60% usable capacity. With balancing, the SOC range can be expanded from 5% to 95%, increasing usable capacity to 90%. This means the battery pack's usable capacity is significantly enhanced.