I copied and pasted this from another forum...If I have a 4S 4200Mah does this mean I can charge (safley) at 4.2 amps or 85% being 3.5 Amps.


The standard recommended charge rate is 1C, which is calculated by taking the mah of the pack and dividing by 1000 to get a amp number for charging.

3300mah / 1000 = 3.3amps - that would be the standard recommendation.

I like to play it safe, and take extra special care of the packs, so I run 85% of the standard recommended charge rate

3.3amps x 0.85 = 2.8amps

Robert -

You are exactly right in your calculations.

For a 3300 mAh pack, a 1C charge rate is 3.3A. If you want to charge at 85% of the maximum rate, that would be 2.8A.

- Jeff

Hey everyone, Again...

What is the voltage not to go below and the not to exceed per cell?

Don't go below 3.0V per cell under load. If you want the maximum performance and life span, don't go below 3.2 or 3.3V per cell.

Don't go above 4.2V per cell.

- Jeff

The rule of thumb is you don't want to put back more than 80 percent of the capacity of the battery