South African engineer and video blogger Luke Bell has set an unofficial world record for the longest quadcopter flight duration. The drone he engineered managed to hover for 3 hours, 31 minutes, and 6 seconds on a single battery charge. The key to this achievement lay in carefully selected components: large-diameter propellers, low-RPM electric motors, a lightweight carbon fiber frame, and semi-solid-state batteries boasting double the energy density. This accomplishment was reported by the publication New Atlas.
One of the primary limitations for fully electric multirotor drones is flight duration. A typical quadcopter can typically stay airborne for only 20–40 minutes, although record-breaking models do exist. For instance, until recently, the record was held by the SiFly Q12 drone, which remained aloft for 3 hours, 11 minutes, and 54 seconds. The short flight time is famously attributed to the low energy density of lithium-ion batteries. Consequently, given the current power source technology, the only avenue to achieve greater endurance is by lowering energy consumption through the installation of more efficient electric motors and propellers, alongside optimizing the drone’s mass and aerodynamics.
South African engineer Luke Bell followed precisely this path, constructing a quadcopter that unofficially set a new benchmark for flight duration. The propellers on the record-setting drone measure 101 centimeters in diameter. The rationale behind utilizing such massive propellers is that increasing blade length reduces the required rotational speed needed to generate the same amount of lift, which in turn lowers energy usage. Electric motors rated at 90 KV (kilovolts per minute of rotation) were chosen because they represented the lightest and most compact options capable of spinning blades of this size at the necessary speed. The 800-millimeter arm length of the frame was determined through aerodynamic calculations designed to minimize the mutual interference between the airflow generated by the propellers. The wiring, totaling 11 meters in length, was selected based on a trade-off between electrical resistance and mass.
The battery was the single most optimized component. The drone utilized a semi-solid-state battery offering an energy density of approximately 320 watt-hours per kilogram, which is double that of a standard lithium-polymer cell of comparable weight. The electrolyte in this specific battery is gel-based. The fact that its peak discharge current is lower than that of lithium-polymer batteries proved irrelevant, as the drone was designed for low-frequency propeller rotation from the outset. Bell further reduced the battery’s weight by removing some of its protective casing, achieving a weight saving of a full 360 grams—roughly the weight of the entire frame assembly. During hovering, power consumption stood at around 400 watts, dropping to 250 watts during slow forward flight.
As a result, the drone flew for 3 hours, 31 minutes, and 6 seconds, surpassing the SiFly Q12 model’s prior record by 19 minutes. Furthermore, after two hours and 14 minutes aloft, the drone still retained 33 percent of its battery charge. Bell himself did not anticipate such a result and failed to arrange for official certification beforehand, meaning the record currently remains unofficial.
For even longer flights, hybrid power systems are often employed. These systems use internal combustion engines to generate electricity, which then powers electric motors that drive the propellers. For instance, in 2020, a hybrid drone produced by the Spanish company Quaternium Technologies remained airborne for 10 hours and 14 minutes.
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