Runtime calculation and question for the guru's

[Finnster]

What I would do is figure out how many mah you put back in, divide that by the runtime (mins.) Then you can figure out how long a full pack will last.

You can even normalize to Watthours by multipling by pack voltage. Ie, If you are using 300 mah/min, running 6S (22.2V) then you are using 6.7 Wh/min.
I typically use 5.8Wh/min or so. Its then easy to figure out runtime on any setup, regardless of the voltage (ie 10S vs 4S)