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10KW Brushless Sailboat Kit


Backordered until Mid October

Convert your 12-29 HP diesel engine to clean, quiet electric. Eliminate noxious diesel fumes and the frustration of filling up at the pump with the 10KW Brushless Kit featuring a Motenergy brushless motor and a 48V 450 Amp Sevcon Gen-4 Controller that can produce up to 10HP continuous and 28HP peak!  Enjoy your sailboat to the fullest, with a silent drive and truly fresh air.

This system is recommended for boats up to 12,000 pounds displacement. All our systems have reverse on-the-fly and contactor disable features. "Brushless" means that the motor does not have brushes that will wear out over time, nor will it be a dangerous source of ignition for on-board gas appliances. Larger boats may require a higher power AC or brushless motor. In the U.S. and Canada, brushed motors are only legal for marine use if onboard appliances and accessories use kerosene or diesel (not propane or gasoline) due to the potential for internal motor arcing.

With Sevcon's Gen4 controller, no reversing contactors are needed. Additionally, the Gen-4 controller has a regen feature than can allow current to be put back into the batteries from the spinning prop while under sail. This does depend on your sailing speed, prop design, and may not be possible in all applications, but is an adored feature for those who are able to utilize it.

A Gear Reduction is not always necessary, and largely depends on the size, efficiency, prop style, and desired speed of your vessel. However, due to the high RPM of the Motenergy Brushless motor, we recommend you consider a gear reduction rather than direct-drive to improve efficiency, provide proper torque, cooling, and help prevent cavitation. Typical reduction is around 2:1, but this ratio will depend on the required prop RPM needed to reach hull speed. Ideal reduction will enable the motor to spin your prop at the hull speed RPM of your prop when the motor is spinning at its max RPM. This number can be calculated using the 50 RPM / Volt constant:

48 Volts * 50 RPM / Volt ~ 2400 rpm max

What about Batteries? Most customers are happy with sealed, deep cycle lead acid, sourced locally to save on shipping. Use 4 in series to get 48v and 100 amp hour capacity minimum. Larger capacity will give a longer run time.

If you choose not to use a gear reduction, it's important to install a thrust bearing somewhere in line with the prop shaft, as most motors are not rated for axial/thrust loads on the shaft. Also note that a heatsink for the Sevcon controller is recommended by the manufacturer.

Kit includes:

  • Motenergy ME1115 or 1306 Dual-Stator Brushless Motor
  • Controller: 48V Sevcon Gen-4 or Curtis 1232
  • Throttle (additional cost) - your choice of: 
    • PB-8 throttle and Fwd/Rev switch
    • ET-134 directional throttle. For harsh environments we recommend the ET-134 as the most robust option. 
  • Tyco High-Quality Sealed Contactor
  • Key Switch
  • Fuses
  • Every kit is individually bench tested
  • Complete wire harness with 10ft key and throttle cable lengths
  • Wiring instructions

Helpful links:

Check out our instructional wiring video!

You may also be interested in the CAN Translator

Those of you that are still in the "research phase" of your conversion should visit one of the electric boats discussion groups and talk to others who are doing or have already done electric conversions.

Gen4 10KW Sailboat Kit Wiring Diagram - for Fw/Rev Switch Option

Gen4 10KW Sailboat Kit Wiring Diagram - for Curtis ET throttles

Gen4 Sailboat Kit Installation Instructions

E-Boat Modeling Spreadsheet (.xls) *Use this to calculate your power needs!*

E-Boat Modeling Spreadsheet Manual (.doc)

Vicprop Calculator


Bought and installed this motor 3 years ago now. Could not be happier! Quiet, reliable and simple! It replaced 19hp Volvo MD2020 in Nordica 30 sailboat. Batteries maintained by Airex 48v Wind generator, while boat is on a mooring.
Great support by the company, good instructions and guidance. I designed and built my own reduction drive 1:2 ratio, driven by toothed belt and pulled.
I have a 37 ft sloop and 48v system using 15kwh of LiFeP04. Very happy with it. I can go all day at 3 or 4 kts, and take it up to 5.5 kts when I need it. No smell/fumes, no maintenance, little sound, and I never have to visit the fuel dock. It doesn't get any better than this!
We have a Tartan 27-2 which has about 8000 lbs displacement. I did our conversion about 6 years ago, and am happy with the results. We have about 4 hours of range... Things like docking become much easier because of the better rpm control. Support from Thunderstruck has been excellent. Electric is not for everyone, but for our use which involves minimal motoring, it works great!
I have a 1976 Islander I-28...I installed the 10kw Thunderstruck motor, 2:1 gear reduction, Clearview Display, along with 8x Trojan T-105 batteries a year ago and couldn't be happier. It replaced the seized up Volvo.

The only issue was my propshaft was 3/4" with a non-standard 1/4" keyway...just make sure you measure your keyway as well as shaft diameter and let Thunderstruck know.

Otherwise install was pretty straight forward and have had no issues. Furthest we have motored so far has been about 16miles at 3.5knots. The majority of the time we return to the dock with +90% battery remaining. Motor is super quiet and we would do it again in a heartbeat.
We really love the electric motor [Ericson 32]
I have been happy with my 10KW Sailboat kit for a year of use now.
I think the system is great! So quiet, and not having to start an engine, just instantly turn the motor on when needed is awesome! [Catalina 30]
Excellent kit! I repowered my 1976 Endeavour 32 (max displacement 11000lbs) with a 10Kw sailboat kit and couldn't be happier. The original diesel was a Yanmar YSE, 12HP, that would barely push us at 4.5kts. Yesterday, first day in the water, we motored at 3.3kts/1400RPM/12Amps, 5.2kts/2048RPM/40Amps. I have 4, 8D AGM batteries for a total of 350Ah, even at 50% depletion I can motor for just over 4 hrs@5kts, we had about 50% amps while motorsailing. Gen 4 controller with the sevcon flat screen shows all the important data. No smell, no noise, no vibrations! Installation was just as fast as advertized! Great customer service, always available to answer questions! Thanks!
Just brought the boat over to it's mooring in a 12 knot wind. FANTASTIC!!!
Thanks for all your help.
Loved the system last summer. Almost instant on, without having to warm up an engine, and much more reliable than the old Atomic 4 ICE.
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