Glossary
Balance charging
Charging a LiPo pack through its balance lead so each individual cell reaches the same voltage instead of only the pack total.
A LiPo pack has a main power lead plus a thinner balance lead with a separate wire for each cell. Balance charging uses that lead so the charger can monitor and adjust each cell individually, rather than only measuring the combined voltage across the whole pack. This keeps the cells even with each other as they charge.
Over time, cells within a pack can drift slightly out of balance from normal use. If a pack is only ever charged through its main leads without the balance connection, that drift can go unnoticed until one cell is overcharged while another is undercharged, which reduces performance and pack life and increases the risk of damage.
Every reasonable FPV charger supports balance charging, and it should be used every time, not treated as an optional extra step. If the charger reports a large voltage difference between cells during a balance charge, that pack is a candidate for closer inspection or retirement rather than continued use.