Key Highlights

  • the aircraft flew more than 75 kilometres on a single battery pack and landed with battery capacity remaining.
  • The Pegasus is a twin-motor drone with a five-metre wingspan.
  • It has been designed to carry two Li-S Energy battery packs.
  • Li-S Energy supplied the battery system, while V-TOL Aerospace provided the airframe and power systems.

Li-S Energy Limited (ASX:LIS), a battery technology developer, has announced that its lithium-sulfur battery powered the EATP Pegasus long-endurance drone on a flight lasting almost two hours. According to the company, the aircraft flew more than 75 kilometres on a single battery pack and landed with battery capacity remaining. The flight was completed under a Commonwealth Government programme known as EATP, and the announcement describes it as a demonstration of long-endurance flight using the company's cells.

The aircraft and the partners

The Pegasus is a twin-motor drone with a five-metre wingspan. It has been designed to carry two Li-S Energy battery packs. Li-S Energy supplied the battery system, while V-TOL Aerospace provided the airframe and power systems. A third collaborator, Halocell Energy, supplied a perovskite solar array for the aircraft.

The announcement states that the programme received a Commonwealth Government EATP grant of just over AUD 1.35 million, and that the collaboration partners matched that funding. Li-S Energy's chief executive, Dr Lee Finniear, said in the release that flight endurance and sovereign capability are critical to Australia's future in this sector.

What the figures show

The battery packs used on the flight are rated at 382 watt-hours each, and the cells alone in a single pack weigh 1.1 kilograms. Li-S Energy says the pack delivered 80 per cent more range and flight time than would have been achieved by an equivalent high-performance professional lithium polymer battery pack for an unmanned aerial vehicle.

The comparison reference given in the announcement is the Tatsu 16000 mAh 6S lithium polymer battery, which is listed at 355 watt-hours, roughly 1.85 kilograms and about 192 watt-hours per kilogram. The company notes an important caveat: the cell-level comparison excludes the weight of the pack housing and the battery management system, and it assumes that flight time scales linearly with cell energy. The 80 per cent figure is therefore a company estimate built on those assumptions rather than a measured head-to-head flight test.

The company also gave expectations for a two-battery configuration, which it has not yet reported as flown. Li-S Energy says it expects the drone to be capable of five to eight hours of flight and a distance of about 250 kilometres when carrying two packs. Those numbers should be read as expectations, not results.

Conditions, risks and next steps

The main qualifications sit in the caveats above: the performance advantage over lithium polymer is calculated at cell level using stated assumptions, the longer-endurance figures for two batteries are expected rather than achieved, and the Patent applications are pending.

What Comes Next

In short, the verified facts are the near two-hour flight, the distance of more than 75 kilometres, the 382 watt-hour pack specification and the stated grant funding..