2018 Seafarer Powertrain





2018 Seafarer Features include Self Contained Wiring Harness with Cable control, Improved Lightning protection, Sealed Permanent Magnet Motor,  Improved Gearbox with Higher Thrust Bearings, Intake Air ducts on Front side (opposite to exhaust air fan),  Wider body to fit into larger engine compartments, 2 inch conduit for power wires, new Access ports for fuse access and New Software.   96 Volt Operation from twin 48 volt balanced battery banks.

The 2018 Seafarer will be available as a Standalone drive or with Electroprop Energy.


The Seafarer Powertrain is ideally suited for Sailing Vessels up to 24,000 lbs in displacement looking to achieve 5.5 to 6 knots continuous vessel speed.

Voltage:  96 Volts  (72 volts Optional)

Maximum Power:  24 KW

Continuous Power:   12 KW

Continuous Current:   125 amps

Motor RPM:  5,000 rpm

Reduction:   Planetary Gearbox

Cooling:  Forced Air,  Motor Fan, Intake Fan, Exhaust Fan.    Intake and Exhaust Fan controlled by motor temperature.

Propulsion Battery Bank:   20 Kilowatt Hours, 210 amp hours, 96 volts

Hybrid Charger:  3 KW or 6 KW

House Battery Bank:   2.5 Kilowatt Hours, 210 amp hours, 12 volts


Click here for Seafarer Drive Drawings and Specifications





The Seafarer Powertrain Includes:

GFCI Protected Smartplug Shorepower Cord cut to length (up to 50 feet available) with integral GFCI protection molded into shorepower cord:   Protects against shorepower induced corrosion in Salt Water and Electric Shock Drowning in fresh water in the event shorepower cord is kicked into water while energized.



Smartplug Shorepower Inlet:   Larger contact surfaces, with O ring seals.    Better wire attachments for longer life.




GFCI protected cord between inlet and isolation transformer – A space saving way of providing an over current breaker for ABYC requirements, while providing additional, redundant GFCI protection.   Identical to the Northshore Safety GFCI protection breaker installed in the shorepower cord.



Charles Isolation Transformer:  The Charles Isolation Transformer is the Heart of the Shorepower Electrical System.     The Charles Transformer contributes to the Safety, Efficiency and Power of the Powertrain and is the most important component of the AC system.

  1. Isolates your Boat’s grounding system from Shorepower Ground.
  2. Eliminates  Corrosion in Salt Water and Electric Shock Drowning in Fresh Water caused by sharing grounds with the dock and other boats.
  3. Suppresses noise from AC line, and reduces voltage spikes that may be harmful to chargers and other electronic equipment.
  4. Eliminates the need for galvanic isolator or polarity indication.
  5. Provides new source of power so fault currents do not flow through the water, making the electrical system much safer.
  6. Wired to provide split phase 120/240 VAC for chargers to increase charger power by up to 65%.
  7. Enables whole boat GFCI protection by eliminating nusiance tripping of the GFCI breaker caused by line filters.



Electroprop AC Distribution:  Provides Split Phase AC distribution to chargers and house AC supply.    Master RCBO breaker for Ground Fault Protection for Ship side AC power.   Individual breakers for charger(s) and house AC circuits.    Waterproof for reliability and to prevent nuisance tripping of Ground Fault Breakers.   Plastic Enclosure to prevent shock hazards and rusting of components.   Built to last to the highest quality.


CMB:   Charge, Monitor and Balance   

The Battery Management System has 5 main purposes

Charges with 3 Different Charging Configurations:

  1. 48 Volt Propulsion Battery Charger Configuration:   Up to 49 amps @ 58 volts = 2.8 KW
  2. Propulsion / House Configuration:  up to 27.5 amps at 58 volts  plus 100 amps at 14.4 volts = 3 KW
  3. 96 Volt Configuration:   Up to 27.5 amps at 116  VDC = 3.2 KW

Monitors Voltage, Temperature and Current

  1.  Monitors the batteries for over voltage and turns chargers off if any individual battery goes over a safety set point, thus preserving the life of the battery.
  2.  Monitors the Batteries for low voltage, or amp hours remaining, and turns off loads when batteries get too low, thus preserving the life of the battery.
  3.  Monitors the amp hours consumed
  4. Monitors DC Load Current, DC Charging Current and DC Battery Current.
  5. Makes Float decisions on chargers using DC Battery Current

Balances 48 volt strings of 12 volt Batteries

  1.  Up to 5.4 amps of top balancing at 14.4 Volts  –  180 watt top balancer
  2.  Up to 2  amps of continuous balancing



Electroprop Waterproof DC Distribution:   Waterproofing extends the life of components by controlling exposure to moisture.   Insulated, Plastic box with O rings eliminates exposure to current carrying conductors to prevent accidental arcing from metallic tools.    Breaker board has Expert Pro Shunt for current measurement.   All cables come in through waterproof strain reliefs.   1 foot long service loop is required.

Electroprop Motor Breaker:   250 amp

Electroprop Logic Breaker: 5 amp

Electroprop Cooling Fan Breaker:  5 amp

Electroprop Charger Breakers: 1 x 60 amp

Solar Breaker:   10 amp

DC converter Breaker:  10 amp

One Accessory Breaker     Choice of 5,10, 15, 20, 30 and 60 amp breakers

Two Fuses for Battery Management System

Two Fuses for Shunt Measurement

The Electroprop DC distribution panel is capable of distributing up to 18 KW of power to your boat systems.    This is the ultimate marine electric DC power panel.

All Breakers are Double Pole Breakers.   The combination of Ground Fault Monitoring and Double Pole Breakers gives the operator the ability to exactly diagnose the system at sea.   Most issues can therefore be resolved immediately allowing uninterrupted use of the vessel.

All Breakers are rated for charging voltages ( 96 volt batteries charge at 116 VDC ) and peak currents (up to 250 amps)  experienced by the system.

Electroprop Ground Fault Monitoring of Floating Battery Bank:    Electroprop tests for Insulation Resistance to ground for the entire 48 volt electrical system.  Floating (or  Isolating) the battery pack is how all electric cars are wired, and how any boat from 48 volts to 500 volts are wired.    We use this method because it is safer, easier to understand, easier to monitor.    The propulsion battery bank is not connected to the boats grounds, underwater metals, AC green wire or 12 volt DC negative.   Keeping the Propulsion Battery Independent insures reliable operation of the vessel.

It is simply the best way of building a high energy battery bank.




8 Northstar Thin Plate, Pure Lead, Advanced AGM batteries:   The Best Marine Battery ever made.  

We use Northstar Batteries exclusively in our systems because they are the best marine battery ever made.    The Northstar Battery is the most forgiving, can be discharged completely without failure, can be recharged faster than other AGM batteries, are forgiving to deep discharges, do not have to recharged immediately and can function in Partial State of Charge (PSOC)  for weeks at a time.  The form factor allows four of these batteries to fit within a 2′ x 2′ x 2′ cube easily making there energy density by volume bigger than other battery shapes and sizes.    There are several sizes of Northstar batteries to choose from.

The Northstar battery will last longer, be more reliable and operate more efficiently than any other lead acid battery.   While operating in PSOC, the Northstar efficiency rivals that of Lithium batteries.   More charging energy is captured and stored for longer ranges.

Thanks Northstar for making such a fantastic battery for electric boats!

Each Seafarer includes two 48 volt Battery Banks in Series


And 1 Northstar 2.5 KWH House Battery.   Identical to Batteries in Propulsion Bank is included.   Charged By 100 amp x 12 volt Charger in Hybrid System or separate Mastervolt 25 amp charger.



Electroprop Fused Power Rail

All fuses are within 6 inches of the terminals.   All Fuses are Waterproof with Boots.   All Conductors are Insulated by Grey and Black Large Conduit.   Connections for Battery Management System are fused in the Power Rail.

Electroprop Seafarer Drive:  

The Electroprop Seafarer Drive has been refined through the years to be  efficient, powerful, tough and reliable.

The Enclosure:   The main feature of the drive is the enclosure.   At 35 lbs, this feature truly pulls its weight.    The enclosure provides air cooling, sound attenuation, lightning protection, and mounting flexibility.    Made from 6061 Anodized Aluminum it is tough enough to stand on.

The Permanent Magnet, Double Stator Motor:   The Seafarer Drive features a Permanent Magnet AC motor that gets its power from a Sevcon controller which makes AC out of the DC from the battery pack.   The motor is run at 4,500 rpm, well within the motor and gearbox rpm capability.

The Planetary Gearbox:  The Planetary Gearbox is capable of running at up to 6,000 motor rpm.   This unlocks the power of the Permanent Magnet Motor.     The Planetary Gearbox is very quiet and powerful with precise German Gears. 

The Sevcon Controller:   Known in the industry as the toughest, most reliable, most efficient controller.    We simply can’t say enough good things about the Sevcon Controller.   Over the years we have refined the software to maximize efficiency.    Sevcon and the folks that run this company are first rate.   I have visited the Main Headquarters in England and worked extensively with the technicians in Boston to develop the best firmware and settings possible for our application.    Many thanks to Sevcon for a great product and a great team to back it up.  

The Sevcon Clearview Display:   Mounted in the front of the Seafarer Drive, the Sevcon Clearview display provides detailed information on the status of the Motor and the Controller, including Motor RPM and Temperature,   Battery Voltage and Current Consumed by the Drive, controller temperature and Operating Status of the Drive system.    We build a drive system to be as reliable as we can, and constantly improve our products, but we can’t predict operating conditions in the marine world including moisture, water or other issues.     For these reasons we like to enable the operator with as much knowledge of the drive system as possible which is the main function of the Clearview display.    Apart from providing all the operating data, the Clearview gives fault management to enable an operator to quickly find any potential issue that might arise in the marine environment.    The Clearview enables the boat owner to troubleshoot the drive system to give the operator the knowledge to bring the boat home safely.   Its important to us that we give you access to information so you can operate the boat to its fullest potential.    The Clearview gives an interface that allows proper sizing of the propeller, proper rpm for the motor, and different acceleration rates to personify the drive to your liking.   The Clearview is mounted in the drive enclosure to protect from the effects of lightning.    The Clearview has been custom programmed for Electroprop for Sailboat Propulsion.

Hall Sense Throttle:   The Standard Throttle for the Seafarer Drive is mounted inside the enclosure for protection from lightning.    The throttles are now operated by cable provided by the customer for his application.

CAN based electronic throttles are available as an option.

Cooling Fans:   The buildup of heat is the limiting factor to continuous power output.   All motors when cool have high intermittent ratings, often two to three times or more of the continuous power rating.   In order to get high continuous power rating, ambient temperature has to be kept cool.    Boats are different from cars and other applications because they are running on continuous power ratings.   In order to maintain low ambient temperatures, all Electroprop drives include ducting for intake air which can be drawn from the cabin or other cooler area on the boat.     Each fan draws around 100 watts so from a power perspective it is an incredible investment.   200 watts from a fan can enable cool continuous power of 12 KW or more.      Running on cooler air also has the advantage of increasing the efficiency of the drive motor, which more than pays of the power consumed by the fan.    Each Electroprop drive system includes SPAL fans, known in the industry to be the best fan for cooling a motor and widely used in the automotive industry.      Airflow is directed to flow through the inside of the open frame motor, plus across the outside of the motor.

Electrical Conduit:   Each Seafarer Drive comes with 2 inch flexible electrical conduit for mounting the main power cables in.    The conduit screws into the side of the Seafarer drive for a solid mounting.    Plastic Conduit is a great way to protect the large power cables feeding the motor.

Lightning Protection:    The enclosure functions as a Farraday’s Cage, protecting all the electronics and the motor inside.


The Propeller:

Choose our High Efficiency Propeller (included) which has high pitch, high blade area ratio, and cupping, an optional feathering propeller,  or a propeller credit and source your own propeller.


The Seafarer Powertrain has been engineered to provide the highest levels of safety, efficiency, reliability and power.    Electroprop drives are leading the way for a clean future for sailing on the water, while providing the highest quality of life aboard.


Our standard system includes what we feel to be the ultimate, complete set of components for a safe, reliable, powerful drive system.    By carefully measuring where you mount the various components, we can customize and prefabricate the entire wiring system to minimize installation time.   Various components can be removed or added to the system to make it ideal for your boat or your budget.

The Seafarer by Electroprop.