All the pictures of boats on this page have been fitted with SEM electric propulsion systems, which are eco friendly and far less polluting than conventionally powered boats. Electric boat users enjoy the virtual absence of noise and vibration, a clean, tidy engine compartment, no smells or fumes, low running costs, negligible maintenance, high efficiency and reliability.
Separately Excited Motors (SEM) are available from 1.5 kW to 20kW for boats up to 20 meters and 30 tons displacement. They are used by discerning private boat owners and commercial operators for day launches, hire boats, traditional river craft, cabin cruisers, canal boats, passenger ferries, tour boats, tug boats and as a source of auxiliary power for sail boats.
SEM direct drive motor – has an excellent mid-power torque range characteristic, which is the ideal solution for propeller drive. The low motor speed reduces noise and combined with the high torque eliminates the need for a reduction gearbox or belt drive. Hardware and installation costs are reduced and gearbox or belt whine is eliminated. The low profile of the motor allows it in most cases to be installed below the cockpit floor enabling ease of movement throughout the boat, while the direct coupling to the propeller shaft increases efficiency.
SEM motor controller - with the introduction of Mosfet technology and the high frequency switching times of these devices, control and operation of SEM motors has become extremely reliable with higher levels of power output and efficiency (motors around 90%, controllers nearly 100%). SEM controllers are rugged and capacities vary from from 200 to 500 amps. The controller comprises the Mosfet block mounted on an alloy heat sink, a safety line contactor, power and control fuses and protective enclosure. Heavy duty plugs for battery, motor and charger connections and a light wire harness from the console to the controller facilitate easy installation.
SEM console – is supplied engraved with a single lever joy stick, providing directional and infinite speed control both forward and astern. The console is fitted with key switch, battery state indicator and ammeter and is pre-wired and tested with light wire harness to the controller.
Battery chargers – are no longer the big and heavy devices of a few years ago. New switch mode technology has reduced the size to small lightweight units with high output currents and fully automatic charging modes, enhancing both the user’s peace of mind and the space available for general storage.