An electric four-copter drone built by a South African father and son engineer recently unofficially broke the multi-rotor drone endurance record with a continuous hover time of 3 hours, 31 minutes and 6 seconds, attracting attention in the industry. This drone not only significantly exceeded the previous result of 3 hours and 12 minutes, but also showed an amazing "margin" during flight - when flying for 2 hours and 14 minutes, the battery power still showed about 33%.
Since the developers did not expect to be able to fly for such a long time, and did not arrange to record the entire flight in accordance with the formal certification process, this result is still in an "unofficial" status.
The project is headed by Luke Bell and his father Mike Bell from South Africa. They have previously become famous in the circle of players with their extremely high-speed electric quadcopters. Now they are trying to "eat both ends" between extreme speed and long range. The design logic of this long-range record aircraft can be summarized as one core principle: to minimize energy consumption in every detail, and not to miss any link that may save power or reduce weight.
In terms of power system, this drone uses T-Motor G40 carbon fiber blades, each with a diameter of 40 inches (approximately 101 centimeters). The large blade and low speed are exchanged for higher lift efficiency, and the same thrust is produced at a lower speed, thereby reducing energy consumption per unit time. It is matched with the T-Motor MN105 V2 Anti-Gravity 90 KV motor. On the premise of ensuring that it can drive a large propeller, the R&D team deliberately chose the smallest and lightest specifications possible to reduce its own weight and loss.
In terms of arm length, the team used five rounds of computational fluid dynamics (CFD) simulations to simulate the mutual interference of the downwash airflow of each propeller disk in the AirShaper software, looking for a layout that could minimize the airflow disturbance, and finally determined an arm span of about 800 mm (31.5 inches). The total length of the motor power supply wire harness is about 11 meters (36 feet), and the optimal wire gauge was carefully calculated in another round of analysis: AWG 18 wire diameter strikes a balance between wire resistance and weight, thereby avoiding "increasing weight to reduce resistance" outweighs the gain. In addition, the central fuselage section has been redesigned twice, resulting in a cumulative weight reduction of approximately 40 grams (1.4 ounces), and this "every gram must be picked out" concept has been copied to the four motors and the entire machine structure.
The battery part is regarded as a decisive link in the performance of the entire machine. The Bell team used Tattu's semi-solid NMC battery cell, which has an energy density of about 320 Wh/kg, which is about twice that of conventional LiPo batteries (about 160 Wh/kg). The so-called semi-solid state means that the electrolyte form is between traditional liquid LiPo and completely solid-state batteries, closer to gel state, which significantly increases energy density on the basis of safety while avoiding the high risks of chemical stability of current all-solid-state technology. The price of this type of battery is a lower peak discharge current, but on this drone, which is designed for low speed and low power, this shortcoming is hardly a limitation.
In order to further reduce the weight, Luke Bell even removed part of the protective shell provided by the original battery manufacturer. Each battery lost about 180 grams, and the two batteries combined lost about 360 grams (12.7 ounces), which is close to the weight of the entire carbon fiber frame. In the hovering state, the average power consumption of the aircraft is about 400 watts; while in slow forward flight, the power can be reduced to about 250 watts, a decrease of about 37.5%, which directly points to the team's next attempt in the direction of "long-term cruise flight".
However, Mike Bell is not romantic about the physical "ceiling" of battery technology in the aviation field. He bluntly stated in an email that the unit energy of aviation kerosene is about 50 times that of the current optimal battery. A commercial airliner can fly for about 20 hours on a tank of oil. However, when replaced with batteries with the same energy density, the corresponding flight time is only about 24 minutes, making the imagination of a "zero-carbon long-range electric passenger aircraft" seem particularly cruel. Even if the battery energy density is doubled, the corresponding flight time will only be extended to about 48 minutes, and tripling it will only be about 1 hour and 12 minutes, which is "still bad." Therefore, he believes that long-range electric flight is almost an "impossible dream" under the current pure battery system. What truly promotes zero-carbon aviation may be a completely different new technological route.
It is worth mentioning that this team not only created what is known as the "world's most efficient" electric remote-controlled drone, but also holds the official world record in the extreme speed field. Australian aerospace engineer Benjamin Biggs recently released an unofficial flight video, claiming that his Blackbird aircraft reached approximately 411 mph (approximately 661 km/h) during a test flight, slightly exceeding the existing record of the Bells. The latter was officially certified by Guinness in January 2026 at a speed of approximately 408 mph (approximately 656 km/h). In the past two years, this speed record has almost jumped from 300 mph in May 2024, 363 mph in October 2025, to 389 mph in December of the same year, and then to 408 mph in early 2026.
At present, the team has begun planning a new generation of Peregrin V5 model, but in the short term, the focus will still be on other projects. When the new machine matures, it will once again hit the top speed record. Mike Bell revealed that they hope to increase the target speed range of V5 to about 450 to 465 mph, and believe that there is still potential for continued breakthroughs after that, but that will be the task of subsequent V6 and V7. In his view, the current main bottleneck limiting extreme speed lies in the propeller technology itself. Once a breakthrough is made in propeller design, battery power will become the next key constraint.