Steps
- Measure internal resistance with your charger or an IR meter, with the pack at room temperature.
- Log it after charging, so each reading is taken the same way.
- Open the battery to see the chart and the latest reading for each cell.
- Watch for a rise since the first reading, or one cell well above the others.
- Retire the pack if a warning shows, or if it's puffed, gets hot or sags in voltage.
Good to know
- Readings change with temperature and charge, so compare readings taken the same way.
- A puffed pack can catch fire. Stop using it and dispose of it safely.
Words used here
- Internal resistance
- How much a cell resists current, in milliohms. It rises as a pack wears out.
- Puffed
- A LiPo pack that has swollen. It can catch fire, so stop using it and dispose of it safely.
- Cell count
- The number of cells in series in a pack, written with an S. A 4S pack has four cells.