ORIGINAL: mmattockx
Dumb***** question of the day - what is balancing cells and why is important to the Lithium Polymer type cells? Do the A123 cells need it as well? I'm a long time glow flier that knows very little of electric flight, please be gentle...
Mark
The following is the general idea. Of course there are tolerances on all the numbers.
1) Lithium cells cannot be charged above 4.2 volts or they will be destroyed. That means no trickle charge after they reach 4.2 volts per cell.
2) If you charge two or more cells in series, you charge the pack to 8.4, 12.6, etc.
3) If one cell has more charge than another it will get to 4.2 before the other and continue to charge beyond 4.2 until the pack gets to 8.4,12.6, etc., and then it might be destroyed if the cells were unbalanced enough.
4) A balancer assures that all cells are at nearly the same voltage and state of charge so they all get to 4.2 at the same time when being charged.
The Thunder Power charger/balancer system will shut down if any cell gets too high. An important safety feature.
Jim O