Originally Posted by suicideneil

There is a simple enough calculation, you just need to decide on what the minimum voltage the cells should hold- 3.2v per cell is recommended as the cutoff point generally, so thats what I tend to use. So ....

When you have a good graph showing the voltage level & current drawn, and you know the pack size/ cell count, you can work out A) the voltage per cell at any given time ( total voltage / cell count = voltage per cell ) and B) what the C rating is based on the amount of current drawn divided by the rated mah capacity of the pack ( say 100amps / 5amps ( 5000mah ) = 20c @ whatever voltage level per cell, obviously above ~3.2v ideally in order for the C rating on the packs label to be concidered at all accurate ).

You can also use the maximum ( current draw ) & minimum ( voltage ) figures provided by the 'dashboard' display of the Eagletree unit to get a snapshot of how the pack performs- with the displayed values you get a worst-case scenareo of how the pack performs; usually these numbers are generated from bursts/ peaks, and can sometimes be a little misleading ( warm packs perform better than cold ones for example ), but are generally pretty sound.