Battery Flight Time Calculator

You should never fully discharge a LiPo battery as it damages the cells and can be dangerous, so most pilots use only 80% of capacity (the Usable Capacity setting). Current draw also varies with manoeuvres, wind and throttle changes, which the efficiency factor accounts for. The "Reserve + losses buffer" result is the gap between the theoretical maximum (100% capacity, no losses) and the usable time — it combines the 20% capacity reserve with the efficiency derating, so it is larger than the capacity reserve alone.

Use a watt meter inline between the battery and ESC during a typical flight or run. Many ESCs also log average current. Alternatively, check the motor specification for current draw at your voltage and propeller combination.

Do not discharge below 3.5V per cell under load (3.7V resting). Most pilots set a timer or voltage alarm at 80% of capacity used. Over-discharging below 3.0V per cell causes permanent damage and can lead to puffing or fire.

Not exactly. Current draw increases more than linearly with throttle due to motor and propeller characteristics. At 50% throttle you typically draw 30-40% of full-throttle current. This calculator uses throttle as a linear approximation for average flying.