Originally Posted by wjvail

I balance charge every time. While it may not be necessary for the health of the battery, it incorporates a very large number of really neat safety features. The most obvious is that by allowing the charger to "know" the voltage of each cell you eliminate the possibility of over charging one of more cells.

Some important background: LiPos are charged using the constant current to constant voltage method. That means the charger will charge at the specified current until it reaches the correct voltage. The correct voltage is typically 4.2 volts per cell - so a 3 cell pack would charge to 12.6 volts. You knew all that right?.?.?



Now say you begin a non-balance charge on a pack with damaged cell. Say the voltages for each cell are 2.0, 3.6, and 3.6. Notice the total voltage for the pack is over 9 volts. Below 3 volts per cell most chargers will not charge. In this case the charger will see 9.2 volts and begin charging. It will continue charging until it see 12.6 volts for the pack. But as we said, one of the cells is not going to charge. The only way to get to 12.6 volts with one of the cells at 2 volts is for the other two to charge to 10.6 volts or 5.6 (!) volts per cell. This will cause a fire.

Had you simply hooked up the balance lead and selected balance charge, the charger will not allow any sell to exceed 4.2 volts. Period. You will still have a damage pack, stuck at 10.4 volts, but at least you won't have a fire.

I'm not going to tell you how to live your life given the option, I balance charge.

Clear as mud?

Cheers,

Bill