Aviation Week Intelligence Network | September 14, 2021

Startup Mobius Energy plans to deliver its first electric-propulsion battery module to a customer in October. The company plans to deliver its modules to the electric aircraft market through a subscription model that includes maintenance, replacement and salvage services to reduce battery waste.

Headquartered in Tustin, California, Mobius already has two purchase orders from electric vertical-takeoff-and-landing (eVTOL) and hybrid-electric conventional-takeoff-and-landing (eCTOL) developers, JP Park, co-founder and chief strategy officer, told Aviation Week.

The company’s standard high-power module, the Husky 2P45, has an energy density of 201 Wh/kg. Noncell components account for less than 20% of the overall module weight, said Park. The module has a high discharge rate of 7C for 7 min., or 9C for 3.5 min., to provide power for vertical flight.

“[The module’s] high charge rate enables fast charging,” he said. “It’s light, simple and compact design enables easy maintenance, on-site swapping and cost-effective reuse and recycling.”

Under its subscription model, Mobius plans to repurpose modules removed from aircraft for a second life in the stationary power market and to recycle them at end of life. The company expects batteries to see 3-6 months of service in the high-tempo air-taxi operations planned by eVTOL companies such as Joby Aviation and Archer Aviation.

“I believe regulators are considering mandatory retirement once the battery reaches 85% of original capacity,” Park said. “However, our customers are telling us that they plan to retire the battery even earlier when it reaches 90% of original capacity and replace it with a new battery to ensure safety and range.”

A subscription-based package including maintenance, replacement and salvage will enable Mobius to refurbish and repurpose modules removed from aircraft for applications such as charging stations, powering data centers and other electric storage operations.

“Our goal is to make the transition to the second-life reuse as cost-effective and smooth as possible so that we can build an economically viable circular economy of batteries,” he said. “Without second-life reuse, we can’t justify the amount of battery waste in electric aircraft and we are not really contributing to the decarbonization of aviation.”

One second-life use of the battery modules will be in a trailer-mounted mobile charging platform Mobius plans to manufacture and sell. In addition to charging electric aircraft, the system will be able to recharge electrified airport vehicles using repurposed battery modules.

Mobius was preceded by InnoTM USA, which was founded in 2014 to codevelop a next-generation battery with Tesla. The company demonstrated the safety of its battery module design, Park said, but after failing in 2015 to secure the investment needed to scale up, switched its focus to aviation.

“Safety is a primary concern with a battery subscription service. It’s not just flight safety, we need to consider safety and security during aircraft storage and repair,” Park said. “The cornerstone of safe operation is a modular design that can enable easy removal and replacement of the battery pack.”

The majority of eVTOL customers are building a 100-150-kWh battery pack, he said. An average pack size of 125 kWh will require 20 Husky modules, weighing 636 kg (1,400 lb.). “We are working with our customers to enable easy removal and replacement of the entire battery pack,” Park said.

Mobius has set up a sister company, Mint Air, in South Korea as an electric aircraft operator. Mint Air’s aircraft partner is U.S. startup Skyworks Aeronautics, which is developing the four-passenger eGyro eVTOL. The companies have signed a letter of intent with the city of Incheon to test-fly the eGyro in South Korea.

“We will set up a test facility in Korea next year in collaboration with Mint Air and Skyworks. After extensive testing and certification, we will launch commercial operation in 2023 and start offering battery subscription services,” he said.

“We are seriously considering a power-by-the-hour service, but it will take many hours of flight testing and data collection before we can confidently offer this,” Park said. “If power-by-the-hour service is offered, it will need to be backed up by liability insurance that requires safety data.”


Lindsay Bjerregaard is Managing Editor for Aviation Week’s MRO portfolio. Her coverage focuses on MRO technology, workforce, and product and service news for aviationweek.com, Aviation Week Marketplace and Inside MRO.