Converting our Test Vessel to Electric Propulsion

August 5, 2021 | Walt White | | Electric Motors for Boats

This Hunter 33 sailboat was our first vessel to receive a NEB-25 electric propulsion system. The whole process was relatively simple. The old diesel engine was disconnected and lifted out at a shipyard using their crane, and then the crane lowered in the new NEB-25 motor and its 10 kWh battery pack into the vessel.

The actual crane operation took less than an hour.

We scheduled an appointment with the shipyard. On the morning of our appointment, we motored over to the dock within reach of the crane, using the diesel to get us there. We then disconnected the diesel engine and the crane lifted it out of the boat. The electric motor and LiFePO4 battery pack were on a pallet nearby, which were lowered into the boat by the crane.

The boat was then moved to a nearby slip where the rest of the electrical and mechanical installation took place.

Main steps in the installation of the new system included:

Prep of saloon area for the new battery pack
Install (strap down and make the electrical connections) of the battery pack
Install the electric motor on its motor mounts
Alignment and connection of the motor shaft to the propeller shaft
Installation of the 7″ Display in the cockpit
Installation of the throttle and key switch in the cockpit.
Installation of the 48V charger in the saloon area
Addition of the 48V charger to the AC electrical panel

Note: The 48V electrical system is completely isolated and separate from the rest of the vessel’s electrical system.

Hunter 33, 2007, docked and ready for the engine pull and Electric Conversion to begin.

48V Lithium Ion Battery Pack, going into the sailboat.

NEB-25 installed in place on same motor mounts as the original diesel engine that was removed. (The wire harness is properly installed in this photo, the wires were in a temporary state).

The motor shaft coupling connects to the propeller shaft in the same way as the original diesel engine.

Why choose electric – the most effective propulsion system in a sailboat

Walt White

Founder and lead systems engineer, working to bring new products to market that make a positive impact to the environment. Our products and services help boats make the switch to battery electric propulsion, harness renewable energy, and solve other challenges involving marine electric propulsion systems.