Cell Balancing
Definition
Process of equalizing charge across cells in a series string by redistributing charge (active balancing) or dissipating excess charge as heat (passive balancing).
Why It Matters
- Maximizes usable pack capacity by preventing weakest cell from limiting string
- Extends battery life by reducing stress on weaker cells
- Required for lithium-ion packs with cells in series
- Passive balancing generates heat that must be managed
Common Pitfalls
- Undersizing passive balancing resistor power rating
- Not balancing during charge (waiting until end-of-charge is slow)
- Expecting balancing to fix mismatched or defective cells
- Not monitoring balancing effectiveness over life