New electric outboard, saildrive, solid state battery – EPTechnologies geared up for next 10 years

EPTechnologies, the Danish electric boat motor, battery and full systems company, celebrated their 10th anniversary in 2024 and is looking forward to the next decade with a  slate of new products shown at METSTRADE.

The big event at the EPT stand was the unveiling of their new Falcon electric outboard, which checks in with a power rating of 130 kiloWatts of continuous power and 200 kW peak (≈ 174 and 275 hp).

Electric outboard, saildrive designed ‘from water up’

The Falcon was three years in design and development – with every aspect of the cowling, casing, lower unit, propeller and hub developed by EPT specifically for electric propulsion.

EPTechnologies Co-Owner Marco Ottiker said this offers many advantages, because many of the high power outboards now available have used the shaft, linkage and lower leg / unit from fossil fuel burning motors and adapted them to the electric powerheads.

The blank slate approach of EPT enables them to be part of – and lead – a general trend in electric boats and motors, which is to address the weight and energy transfer efficiency of every part of the boat and propulsion system.

Inefficiencies have been easy to ignore with combustion engines– basically you just put on a bigger engine (or more engines) and burn more fuel. It is a little more complicated than that with electric boats.

Read the Plugboats overview of electric motors at METSTRADE 2024

We’ll step back for a minute and talk about the new saildrive at the EPTechnologies booth, which played an important role in the design of the Falcon but was a bit overshadowed by the hoopla surrounding the outboard.

EPT has had saildrives for about three years now, both stationary and a ‘turntable’ model with 360º rotating leg. They originally married their motors with the lower leg of the most common SDs in the market, those of Yanmar, adding their turntable on top. With the announcement last year by Yanmar that it would be producing and marketing its own electric saildrive, EPT began developing a complete unit from top to bottom.

The new EPT Saildrives are adaptable to the hull fittings of Yanmar, Volvo Penta and Oceanvolt motors, but more important is the work that was done on the gearing in the ‘L’ connection of the drive, where the energy is transferred from the vertical rotation of the motor and shaft to the horizontal rotation of the propeller.

As they looked at optimizing the gears for the RPM and torque profile of their electric motor, the team realized they could make it all slimmer and lighter than what needs to be used with  diesel motors.

APT has an in-house testing pool where they could then fine tune the casing around the slimmer gears to give the unit a much more hydrodynamic profile. That learning was then applied to the Falcon’s lower leg.

Next they turned their attention the propeller and hub – the central part of the propeller that fits onto the shaft as a connection point between the blades and the engine’s drive train.

Many combustion outboards have the exhaust exit through the prop and hub, so a concave flared diffuser ring slighter wider than the hub is used to prevent the gases from feeding back into the blades. It also creates a small vacuum and turbulence that lowers the propulsion efficiency.

Greater efficiency in propeller / hub

Since an electric motor has no exhaust, the EPT engineers used the opportunity to gain extra efficiency by replacing the flared diffuser ring with a tapered cone.

The cone helps create laminar flow of the water and makes it behave much the way air does when going over an airplane wing. Ottiker, who was an AirBus pilot for 15 years before joining up with EPTechnologies Founder Konrad Falkenberg, says the efficiency is the result of the water travelling smoothly, in regular paths where the velocity, pressure, and other flow properties at each point remain constant.

Another innovation, which also came from their turntable saildrive, is that the whole lower unit rotates a full 360 degrees, independently of the motor block and upper unit, which is fixed to the boat. This provides exceptional handling, even in tight spaces and enhances maneuverability in confined spaces, eliminating the need for additional bow thrusters.

Designing all of this in-house meant that EPT was able to determine the best materials and construction processes while also trimming any unnecessary weight in the the components. The company says the Falcon weighs approximately 100 kg less than traditional combustion engines. That is weight that can be allocated to batteries for extending range.

Another advantage that came out of the work on the saildrive was a shaft casing with a customizable length that can be tailored to fit any boat geometry – even long enough for hydrofoiling applications. The cowling of the Falcon can also be customized with different colours and insets to match the boat.

Solid State batteries for marine

The other big thing EPT showed at METSTRADE is their Solid State LV battery. Although it officially debuted at the show in 2023, it is still a significant story for the future.

Solid state battery technologies are only now coming on the market, and generally the benefit being sold is a higher energy density / lower weight – the ability of solid state chemistries to store more electricity per kilogram of battery material.

EPT offers two solid state battery chemistries – LiFePO and NCM – and while the NCM version does have a significantly higher energy density, the big selling points for the LFP version are safety and life span. (We’ll get to NCM in a minute.)

Last year at METS the safety of the LV SS LFP battery was dramatically demonstrated when Ottiker punctured it with a screwdriver as Ben Ellison of the Panbo.com Marine Technology Hub looked on (You can read Ellison’s account and see a video »» here).

In the worst cases, and depending on the charge of the battery, the result of it being punctured by a metal object like a nail or screwdriver can be fires, explosions, or both. All that happened with the EPT battery was that it had a screwdriver sized hole in it.

This past year the battery achieved DNV certification, a big deal because DNV is the global organization that establishes criteria for safety (and other aspects) of products for the maritime industry.

Ottiker tells an amusing story about the certification process.

After submitting the battery, Ottiker got a call one day from the DNV Inspector. “I have to get them to react to finish my report” he said. “How am I supposed to test these? I can’t make them burn when I punch a nail into them and I can’t overcharge them.”

10,000 charge / discharge cycles

Ottiker had to make some phone calls himself to find the solution, which was unusual, to say the least: “Apparently you have to heat the nail until it is glowing, about 400 degrees” he advised. Finally the inspector was able to put together a report and the certification was received.

On the charging front, the battery can take up to 10,000 charge/discharge cycles and cannot be damaged by overcharging or by having the battery taken down to zero charge.

The other major lithium ion battery chemistry is NCM, standing for Nickel – Cobalt-Manganese. This naturally has a higher energy density than LFP and the solid state material increases the difference. But while the EPT NCM solid state has an energy density of 360 watt hour per kilogram, (non solid state are about 250 Wh/kg) the battery is only viable for about 700 charges.

The LFP batteries have found a very receptive market among ferries and other large vessels, while EPT recommends the higher energy / shorter life NCM models only for some very specific workboat applications.

While electric marine propulsion has been around for more than 140 years (see The Gustave Trouvé Awards), the modern era started only a short time ago and EPTechnologies is one of the pioneers. 

Five years ago it had only 5 employees…one year ago there were 30…and now the team counts 60 employees working on the full range of electric propulsion technologies: full electric, hybrid, inboards, outboards, a ‘drop-in’ inboard/outboard system, thrusters, saildrives, batteries, monitoring systems and interfaces and more, for everything from recreational powerboats and daysailes to oceangoing catamarans to large ferries and cargo vessels.

Last month the business community of their hometown awarded EPTechnologies the 2024 Sønderborg Comet Prize “given to a younger, rapidly growing company that, with a sustainable and scalable business concept, shines among Sønderborg’s companies.”

The judges said “you have created a scalable business model and are already a major international player in your field.
 The company has a clear sustainable profile and is almost “born green” with physical products and digital solutions that help save a lot of CO2.
 You create jobs both in Sønderborg and abroad and have employees from many different cultures and countries. 
You have fought hard – and with faith in the idea and great perseverance have created a fantastic company.”

From Ottiker’s perspective he says that after the past few years of growth “Now I think we will have a little stabilization phase, which is needed, and good. Now we can delegate tasks, we can do more projects. And, yeah, that’s really, for me, very exciting.” Stay tuned.

EPTechnologies