mAh to minutes
Capacity in mAh is charge, not energy. Runtime at a constant average current: Ideal (min) = Capacity (mAh) / (1000 × Average Current (A)) × 60. A 5000 mAh pack at 25 A gives a 12-minute ideal.
Usable capacity
You never drain a LiPo to zero — a usable fraction (e.g. 0.8) leaves a reserve for pack health and voltage cutoff. Estimated = ideal × usable fraction.
Why real runtime differs
Average current is an average: acceleration spikes, cold packs and aging all shorten real runtime. Calibrate the average from logged runs, not guesses.
Where it is used
The Battery Runtime Calculator applies this formula; boat and aircraft variants (boat, plane, drone) share it with tailored guidance.