Drone Battery Flight Time Calculator

DJI publishes two flight figures for each aircraft, both measured in still air: a maximum hovering time and a maximum flight time. For the Mavic 3 it prints 40 minutes hovering and 46 minutes flying, on a pack it lists as 5,000 mAh at 15.4 V and 77 Wh. Divide that energy by each time and you get the average power the figure assumes: 77 Wh over 40 minutes is 116 W, and 77 Wh over 46 minutes is 101 W.

Those two divisions are the whole method behind this calculator. There is no hidden fudge factor and no blanket discount baked in. Feed it the pack DJI prints and the power DJI's own pair implies, and it hands back DJI's own minutes. The presets on this page all use the hovering figure, which is the higher of the two powers and so the shorter, safer estimate, because the flight-time number assumes a steady cruise in dead-calm air. Your own flight is shorter still, for two reasons you can name and enter: a higher average power, because wind, climbing and payload all cost watts, and a landing reserve you keep instead of flying the pack flat.

The energy step is the same one behind every runtime estimate, watt-hours divided by watts. Our Wh to Ah converter turns a pack listed in one unit into the other, and the same arithmetic drives our e-bike battery range calculator, where the divisor is watt-hours per mile instead of watts.

DJI prints each pack's capacity, voltage and energy beside two times it measures in still air: a maximum hovering time and a maximum flight time. The last two columns divide the pack energy by each of those times.

Read the last two columns as the power each of the maker's own pairs implies, not as a measurement of your aircraft. Both round up to the next whole watt. The presets load the hover column, because it is the higher power and so the shorter, safer estimate, and because the flight figure assumes a steady cruise in dead-calm air: the Mavic 3 preset returns 39.8 minutes against a printed 40. If your flight log shows a higher average than the hover column, type it in. That number, not a blanket percentage, is what shortens your flight.

Lithium packs hold a lot of energy in a small space, and that is exactly what makes a damaged or over-discharged one dangerous. A punctured, over-discharged or overcharged pack can vent flammable gas and ignite, which is why the FAA publishes separate carriage rules for lithium batteries.

Tattu, which builds LiPo packs for unmanned aircraft, sets the floor in volts rather than percent. Its operating instructions read: "For Tattu series batteries which are used for Unmanned Aircraft system, The recommended cut off voltage is 3.5V per cell", with an absolute limit of "Never discharge battery to a level below 3V per cell under load." Set your flight controller alarm at the maker's figure and land when it sounds. That voltage floor, not a round percentage, is what the reserve you enter above protects.

Charge on a non-flammable surface and never unattended. Grepow, another pack maker, prints 3.85V per cell as the storage voltage for a 3.7V cell, so park packs there rather than leaving them full for a week. Never charge a puffed, dented or crash-damaged pack; hobby shops and battery recycling points take them. Deep discharges shorten the life of any lithium cell, which our depth of discharge guide covers in full.