Cell pro 4s

[MXRACERX43]

Hello everyone. I am using a cellpro 4s charger for my 3s lipos in a Trex 450. I am a nitro guy so new to lipo charging. I read in another post that when you connect your battery to the 4s it is taking into account the 80/20 rule. So it does not show the actual capacity left when it shows fuel %. Is this correct? So I can fly down into the single digits say 5-7% and still be safe?

[Jotto]

It seems so to me. The charger shows 15% remaining fuel when 60-70% of the battery capacity is used. It may also be an inaccuracy in the fuel estimation, as it's hard for the charger to guess the exact capacity of the battery when it starts charging.

To measure the exact remaining capacity, you have to charge the battery completely and see how many Ah the charger has added to the battery.