When i balance charge my new Turnigy 2s 5800mAh using Thunder AC6 at 5.0A, i understand that it will charge the lipo cell from whatever remaining voltage per cell to 4.2v per cell.

For example if the 2s are at 3.85v and 3.89v, it will balance charge to 4.20v and 4.20v.

I understand that my Thunder AC6 lipo charger is limited to 50Watts and 5.0A charge rate.

To charge my new Turnigy 2s 5800mAh, it should take around 8.4v x 5.8A = 48.72Watts in 60mins.

But again with my charger limited to 5.0A, it only charges at 8.4v x 5.0A = 42Watts which means it takes around 70mins+ to reach full capacity.

My questions are:

1. If i overcharge (without balance charge) my new 2s lipo above 8.4v, let's say 8.6v, how do i bring down the voltage?

2. When i charge my other new lipo in balance mode, it perfectly balanced to 8.4v but the charged capacity reading was at 2989mAh. Does this mean the charger top up the capacity or only charged at 2989mAh?

3. Is there any device to monitor lipo capacity?