Pancake axial-flux motor powers new Propel electric outboard

Groundbreaking Saietta AFT motors for lightweight EVs and motorcycles will be powering the all new Propel electric outboard and inboard boat motors making their debut this week at METSTRADE 2021.

AFT stands for Axial Flux Technology, axial flux describing an electric motor configuration that is flat – like a pancake – instead of cylindrical like most motors. To be simplistic, it means that the magnetic forces are aligned parallel to the axle of the motor (hence ‘axial’) instead of radiating out from the axis, which is called radial flux. Axial flux typically provides more torque per volume, and the Saietta AFT 140 motor has been acclaimed for being particularly efficient.

High torque per volume and high efficiency translate into two things that are very appealing in an electric boat motor: less weight and more range. Hence the the launch of Propel,  Saietta’s marine propulsion division, with two elegantly designed motors: the Propel S1 electric outboard and Propel D1 electric inboard.

Propel S1 electric outboard: 10kW, 25hp

The Propel electric outboard can generate continuous power output of 10kW from a 48V battery and equal the acceleration and speed of a 25hp ICE engine when matched with the company’s four bladed propeller.

The prop was designed to make the most of the AFT 140 motor’s torque and RPM profile. After months of tests and tweaks using computational fluid dynamics software, the four-blade design came out as providing the optimal balance between size and motor performance. For complete system optimization Propel is also building its own LiFePO battery packs for the S1, although it can be run on other packs.

Part of the S1’s innovative design is an advanced motor controller integrated on top of the pancake motor that shares the outboard’s closed-loop cooling system to provide maximum performance overall and next-to-zero maintenance. 

diagram of closed loop cooling system

Sander van Dijk, Propel’s Managing Director and Chief Technical Officer, said “In developing the Propel brand, it became immediately clear that users want simple and worry-free access to cutting-edge electric propulsion technologies. So, first principle is no motors or electronics below the waterline, and a drivetrain that is virtually maintenance-free. Secondly, our advanced products must be simple and safe to operate by everyone.”

To that end, the Propel team worked relentlessly on designing and testing user interfaces that offer obvious and easy functionality. The S1 electric outboard is available with either tiller or remote steering and both options feature an integrated waterproof display that can be instantly read even in the brightest sunshine. These design features along with the satin silver and white finish, create an overall look and feel of simplicity, sustainability and elegance. 

Propel D1: an electric crate motor ready-made to replace diesel

Propel’s second product is an inboard series of electric crate motors designed specifically to replace ageing diesel engines. Following van Dijk’s goal of making it as easy as possible  for boaters to ‘go electric’,  the D1 inboards are small but have everything built in, with no external controllers or pumps.

Propel electric inboard boat motorThe design makes it simple to take an old diesel out, install the new motor on the same foundation, connect drive-shaft, water and battery, and be ready to sail. The D1 provides 10kW / 20hp equivalent with a torque of 60 Newton Meters, 105 NM peak. It has the Propel closed-loop cooling and ships with the same sunlight readable display as the S1 as well as a DC-DC converter to power onboard 12V devices.

The design and introduction of these motors from an innovative electric mobility company like Saietta is a great endorsement for the future of electric boating as part of the global transportation revolution.

Wicher Kist, chief executive of Saietta Group, said: “Helping the world go further and accelerate towards a cleaner and more sustainable future has always meant more than just road transport to Saietta. It’s been a long-held ambition of mine to bring Saietta’s AFT electric motors to busy waterways, and I’m delighted to see that come to fruition today with the launch of our new subsidiary Propel.”

CTO van Dijk agrees. “Electric propulsion isn’t a solution, it’s a leap forward and it’s happening in every other aspect of life. We’re proud to be bringing this innovation to the water.” 

Propel Axial Flux Technology motors available for order now

There are 100 launch edition units of the Propel D1 inboard available for order now with delivery starting in early 2022. The units ship with a 6.5kWh LiFePO4 battery or doubled up 13kWh package with introductory prices of €12.490 and €18.290 respectively.

The S1 Propel electric outboard can be pre-ordered for delivery in spring of 2022 with a refundable deposit of €100 – expected full price is €5,900. It can be ordered with tiller or top mount controller and shaft lengths of 15, 20 or 25 inches.

To order and for full specifications, visit the Propel website.

Be sure to check out all the electric boat exhibitors at METSTRADE in our Plugboats Guide

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