BATTERY INNOVATION • ADVANCED AIR MOBILITY
CJI RESEARCH
Putting the mighty in aircraft batteries
Known best for its groundbreaking work in developing electric aircraft motors, magniX has made its first foray into batteries with the help of NASA. Words by Yves Le Marquand
BATTERY INNOVATION • ADVANCED AIR MOBILITY
CJI RESEARCH
Putting the mighty in aircraft batteries
Known best for its groundbreaking work in developing electric aircraft motors, magniX has made its first foray into batteries with the help of NASA. Words by Yves Le Marquand
IN NORSE mythology, Magni is the son of Thor and Járnsaxa. His name means ‘mighty’ in Old Norse. There have been many references in popular culture to Magni, from the Marvel comic series to hugely popular online video game World of Warcraft. But his name has never been adopted quite as aptly as by electric aircraft motor (and from this year battery) manufacturer magniX.
The electrification pioneer has been making headlines for its work developing and flying electric motors for aircraft. Highlights include in 2019 the first flight of a De Havilland Beaver seaplane retrofitted with an electric power unit (EPU) in partnership with Vancouver-based seaplane operator Harbour Air. And in September 2022, the first all-electric flight for Eviation’s Alice aircraft. Electric motor manufacturer magniX has been flying electric aircraft since 2019 and in that time has flown five platforms.
Leveraging its experience in developing and delivering EPU solutions for the burgeoning electric aviation industry, magniX is expanding its attention to battery development. The firm recently unveiled its first battery product line, aka Samson, focused on delivering high energy density and “unmatched” cycle life. The Samson300 is the first in the line offering energy density of 300 Watt hours per kilogramme (Wh/kg) and cycle life of more than 1,000 full-depth discharge cycles to reduce operating costs.
Combined with the firm’s magni350/650 electric engines, the Samson battery allows magniX to offer a complete electric powertrain.
“We realised we had been playing with batteries for many years. You can have the best electric motor to power an aircraft in the world, but without an energy source you are not going to realise the dream of electric flight,” Ben Loxton, vice president of Energy Storage Systems and the NASA Electric Powertrain Flight Demonstration (EPFD) programme at magniX tells us.
Samson’s development is being advanced under NASA’s EPFD programme, which has seen magniX undertake conversion of a De Havilland Canada Dash 7 aircraft into a hybrid-electric propulsion demonstrator.
“We’ve always kept a close eye on batteries, we have worked with a number of battery manufacturers and have used a variety of batteries in our demonstrators. What we learned over that period, particularly from our work in the EPFD programme where we intended to go out and use and third-party battery, is that there aren’t any products that meet the requirements we have, and believe the industry needs, to have a certified, in-service aircraft in the next few years,” says Loxton.
In August magniX unveiled the Dash 7 airframe that will be retrofitted as part of the EPFD programme with NASA. In the next phase, the aircraft, provided by Air Tindi, will have one of its four turbine engines replaced with a magniX electric powertrain, with test flights planned for 2026.
The De Havilland Dash 7 regional turboprop takes flight as part of the EPFD.
The De Havilland Dash 7 regional turboprop takes flight as part of the EPFD.
Riona Armesmith, chief technology officer at magniX says: “We have learned so much through integrating these things into aircraft. We’re not building a battery from a sole manufacturer’s perspective, we are not taking a battery chemistry and trying to turn it into an aerospace battery. We are asking what, from the view of an aircraft operator, are the needs of the industry? Which I think is a fundamentally different approach.”
Samson 300 boasts a number of key features, according to Loxton. Amongst patented safety technologies such as cell level protections from thermal runaway and ability to store batteries for long periods at zero charge, active on ground cooling during charging and modular architecture to allow for simple replacement, the most impressive capability is its 1,000 full-depth discharge cycles.
Discharge cycles determine the usable life of the battery, the cost of which will be among the primary operating expenses for electric aircraft operators. The end of usable life for an aircraft battery typically arrives when the full charging capacity of the battery reaches about 80% of the original. This means regulations will stipulate operators need to replace the battery at this point, and that could become a costly process especially for those operating high-volume services like air taxi flights. Or those flying missions which require most of the battery’s state of charge to operate.
“A lot of what we do is to look at what this means for the end user,” Armesmith tells us. “In developing this cell, we have been very strict on cycle life. Yes, we want energy density, but not at the expense of cycle life. We needed to achieve a reasonable balance. For me, if you have a fantastic cell that is, let’s say, 500Wh/kg, but it can only do 100-200 cycles, economically that does not work.
“As we go forward beyond our 300Wh/kg module, there is going to be a real focus on keeping that cycle life up. That is the only way we can make this economically viable.”
The Samson300 battery offers a cycle life of more than 1,000 full-depth discharge cycles. When combined with magniX's electric engines, the battery allows the firm to offer a complete electric powertrain.
Riona Armesmith, chief technology officer at magniX says: “We have learned so much through integrating these things into aircraft. We’re not building a battery from a sole manufacturer’s perspective, we are not taking a battery chemistry and trying to turn it into an aerospace battery. We are asking what, from the view of an aircraft operator, are the needs of the industry? Which I think is a fundamentally different approach.”
Samson 300 boasts a number of key features, according to Loxton. Amongst patented safety technologies such as cell level protections from thermal runaway and ability to store batteries for long periods at zero charge, active on ground cooling during charging and modular architecture to allow for simple replacement, the most impressive capability is its 1,000 full-depth discharge cycles.
Discharge cycles determine the usable life of the battery, the cost of which will be among the primary operating expenses for electric aircraft operators. The end of usable life for an aircraft battery typically arrives when the full charging capacity of the battery reaches about 80% of the original. This means regulations will stipulate operators need to replace the battery at this point, and that could become a costly process especially for those operating high-volume services like air taxi flights. Or those flying missions which require most of the battery’s state of charge to operate.
“A lot of what we do is to look at what this means for the end user,” Armesmith tells us. “In developing this cell, we have been very strict on cycle life. Yes, we want energy density, but not at the expense of cycle life. We needed to achieve a reasonable balance. For me, if you have a fantastic cell that is, let’s say, 500Wh/kg, but it can only do 100-200 cycles, economically that does not work.
“As we go forward beyond our 300Wh/kg module, there is going to be a real focus on keeping that cycle life up. That is the only way we can make this economically viable.”
The Samson300 battery offers a cycle life of more than 1,000 full-depth discharge cycles. When combined with magniX's electric engines, the battery allows the firm to offer a complete electric powertrain.
Usable life also brings with it a new challenge: what do you do with batteries once they lack the charging capacity for aircraft operations? It is an area magniX is keeping a close eye on as it develops the Samson product line. Although detailed plans for recycling batteries are yet to be defined, the firm plans to keep production “as domestic as possible” including everything from mineral extraction right through to cell production to minimise climate impact.
“These are factors we are looking at right out into the future,” says Loxton. “We are thinking about what you might do with the battery packs through second and third lives once they are no longer fit for the aircraft. And then how you reclaim and recycle those materials back out of it. It is an important aspect we will be looking at over the next five or so years as our batteries go into service planning.”
While magniX is not revealing the specific battery chemistry it has selected for the Samson product line, Loxton says it is “nothing super exotic”. The team decided on a “reasonably static” chemistry that can be produced using equipment today.
“There are exotic chemistries in the lab with small coin cells where people are demonstrating 400-500Wh/kg, but that is almost impossible to produce at scale. We are probably the best part of five years away from having the specialised production techniques required to produce large numbers of those cells at a reasonable cost and reliability rate,” explains Loxton. “That was one of the key drivers behind our chemistry decision.”
The company has a roadmap for battery development which, akin to Thor’s son Magni, will see its battery cells become more and more mighty. Loxton says magniX plans to continue investing in cell R&D and has a “good line of sight” to future upgrades in energy density levels amongst other parameters in the coming years.
“If you have a fantastic cell that is, let’s say, 500Wh/kg, but it can only do 100-200 cycles, economically that does not work...”
Riona Armesmith, chief technology officer, magniX
“Our vision is that you will send out the initial batteries to customers. Then, when they are used up in a few years and the customers want to replace their batteries or continue to upgrade their fleet, we can come back with a higher energy density battery,” says Loxton.
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What battery tech means for business aviation
THE INDUSTRY has long been an incubator for new, disruptive technologies. Advancements in aerospace technology such as winglets, composite airframes and fly-by-wire systems were all tried and tested in business aviation first.
Logic suggests that at least a portion of the latest incumbent of disruptive technologies will also find their feet in business aviation and battery-electric aircraft are certainly no different.
German eVTOL developer Lilium is targeting the luxury end of air travel as an entry market. The startup, currently working on its six-passenger Lilium Jet powered by 36 electric motors, has announced deals with industry operators including Luxaviation, Philjets and GlobeAir. It also has an exclusive dealership deal in the UAE, Cyprus and Israel with brokerage ArcosJet.
Fellow German startup VÆRIDION has also singled out business aviation as a key target entry market for its battery-electric aircraft – the nine-passenger Microliner. The company has cooperation agreements with Danish charter operators Copenhagen AirTaxi and Copenhagen Helicopter.
Co-founder and CEO Ivor van Dartel says VÆRIDION decided on the business aviation-first pathway partly due to regulations. If an aircraft holds nine seats or below, it still qualifies for level three of CS23 – EASA’s regulation for normal, utility, aerobatic and commuter aeroplanes.
The same is true in the US. The regulatory framework that enables initial operations of electric aircraft will see them flown as Part 135 services. Those are conducted under the set of Federal Aviation Regulation (FAR) guidelines relevant to non-scheduled, commercial aircraft operations – in other words, business aviation.
