EP Systems Prepares To Deliver First EPiC Electric-Aircraft Batteries

EP Systems Epic battery platform
Credit: Diamond Aircraft

Electric Power (EP) Systems plans to ship its first EPiC modular propulsion batteries to electric-aircraft developers this summer for testing in their system-integration laboratories. Delivery of safety-of-flight hardware for use in piloted test flights is to follow.

The Logan, Utah-based startup is on track to obtain FAA technical standard order (TSO) certification for its first-generation EPiC platform in the second quarter of 2023, says President and CEO Nathan Millecam. EP Systems also has added a deal with Hyundai’s Supernal to a growing list of customer agreements.

TSO approval is expected to enable the battery system to be used in type certification of new electric aircraft or supplemental type certification (STC) of modified aircraft. Austria’s Diamond Aircraft, for example, plans to use EPiC in its eDA40 electric trainer under an STC for modification of the piston-powered DA40.

Using a TSO enables a modular approach that allows the system to be scaled to different aircraft applications, Millecam says, and EP Systems has worked with the FAA to develop a TSO for a propulsion battery. This requires certain functional data to be collected for use at the aircraft level, he explains. 

In addition to Diamond, EP Systems has announced agreements to supply batteries to French electric-aircraft startups Aura Aero and VoltAero as well as Japanese electric vertical-takeoff-and-landing (eVTOL) developer SkyDrive. Boeing, Embraer and others have used EP Systems’ batteries for flight-testing.

Supernal and EP Systems on July 20 announced a partnership to accelerate development and production of lightweight, certifiable eVTOL vehicle batteries. The broad collaboration covers the energy storage system and associated ecosystem, including fast-charging infrastructure, the CEO says. 

The companies are expected to align their technology road maps, and EP Systems will support U.S.-based Supernal with research, trade studies and hardware. Automaker Hyundai is developing an all-electric urban-air-mobility eVTOL in the U.S. and a hydrogen-electric regional-air-mobility vehicle in South Korea.

EP Systems, meanwhile, is collaborating with partners on a road map of advanced cell technology for batteries. The first-generation EPiC system uses lithium-ion cells with an energy density of 230 Wh/kg. The second-generation EPiC cell, now in qualification testing, is expected to achieve 280 Wh/kg.

The EPiC system is designed so it can be upgraded as battery technology improves. Cell qualification for production takes 1-2 years, as both technology and manufacturing readiness levels must be synchronized closely, Millecam notes, so the Gen 2 system is expected to follow two years after Gen 1 is TSO-approved.

EP Systems is putting an “energy as a service” business model in place with its launch customers, he says. When EPiC batteries reach the ends of their useful lives in the aircraft, it is expected they will be replaced with upgraded systems and the modules repurposed into second lives in grid-power storage systems.

Millecam cites the “compelling economics” of grid storage at vertiports and airports. This is because, compared to electric vehicles, the larger battery systems in eVTOLs and electric fixed-wing aircraft will place substantial fast-charging loads on the electrical grid, driving up energy costs. Storage batteries can be recharged from the grid more slowly, at lower energy cost, and then used to fast-charge aircraft.

“Grid-storage batteries are critical to reducing costs,” he says. In addition to “future-proofing” aircraft through upgrading the EPiC platform, it is anticipated EP Systems’ energy-as-a-service model will lower the entry cost to convert aircraft to electric propulsion via an STC and enhance the economics of new aircraft.

The startup’s batteries have flown on eight different eVTOL, fixed-wing and uncrewed aircraft. In addition to having a broader flight-time experience than its competitors, EP Systems “will be first to certify, with the most safe system, is scaling up faster and has the largest commercially contracted backlog,” Millecam adds.

EP Systems plans to expand its battery production footprint over the next three years, helped by a nine-year, $69 million tax credit from the Utah state government. The first phase, a pilot line capable of producing 66 megawatt-hours of batteries a year with a single shift, is to be completed by year-end. EP Systems plans to inject a high degree of automation into battery-module production by the end of 2023.

Graham Warwick

Graham leads Aviation Week's coverage of technology, focusing on engineering and technology across the aerospace industry, with a special focus on identifying technologies of strategic importance to aviation, aerospace and defense.


1 Comment
Would be interesting to know the basics of their cells. Cylindrical, pouch, or prism? Which chemistry? Methods of temperature control? Shouldn't be too secret, if they have to convince the FAA of their safety.