E-V Concepts

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Electric propulsion for boats dates back to before the internal combustion engine. For over 30 years Electric Vehicle Concepts has been helping sail and power boat owners convert their internal combustion propulsion to battery powered electric propulsion.

                    Electric Propulsion  vs.  Internal Combustion Engines

Horsepower and torque ratings are much different between the ICE and electric motors. Electric motors have superior torque over the gas or diesel engines at low speeds. The lowest speed the Internal combustion engines is capable of maintaining a rotation idle is at 700-800 rpm because of the reverse effect of friction and compression. In order to develop enough torque to drive the boat forward the rpm must be 1500-2000 rpm. From then on the torque output increases with rpm up to 5500 rpm.

The electric motor has an idle speed of 0 rpm and develops maximum torque at 1 revolution, which is unique to electrical motors. Another advantage of the electric system is having instant power. There is no need to wait for the engine to warm up. Just turn on and go. There is no need for a gearbox as the electric motor can reverse rotation. One can go from full power forward to full reverse in an instant.


The battery powered electric propulsion system is virtually maintenance free since there are very few moving parts in comparison to the Internal combustion engines that are very complicated machines.

The fuels for the ICE are flammable and poisonous. Usually fuel injection systems run at very high pressures especially to pump diesel. Water and foreign elements clog up fuel lines and the very sensitive fuel injection systems. The fuel tanks build up condensation and create rust. The water does not mix with the fuel and will not compress in the fuel injection system. The fuel in the tanks and oil in the engine and gearbox begin to go bad from not being used.

 Electric propulsion systems get their energy from fuel cells usually in the form of storage batteries. Most fuel cells can stand for years with no change or loss of power. The lead acid battery has been around for more than a hundred years and has made great improvements in the last 30 years. The ONLY periodical maintenance to electric propulsion system is replenishing the water level in your lead acid batteries. There are watering systems available to handle this maintenance. Battery technology continues to advance and we have maintenance free and gel filled batteries.

For the past 12 years Chevron oil and General Motors have controlled the patents for advanced nickel hydride battery technology. This was the top technology of its time although we could not use it. We now have the lithium technology that the Chinese are producing.

The high compression ICE is very noisy and creates a good deal of vibration. The ICE creates its energy by burning the fuel to create heat and poisonous carbon monoxide gasses. An average of 20 to 30% of the fuel is burned in the engine and rest of the fuel goes out the exhaust into the water.

With over 100 components moving metal to metal adds a great deal of heat from the friction and a short life span. Your cooling system must control the temperature from becoming to high and melting the aluminum parts. Sucking the water through a HOLE in the bottom of your boat is the most common practice. One of the most important maintenance for ocean going yachts is keeping the water inlets and screens from getting clogged, usually from barnacles growing on them.

Very little hot air is created by the electric motor under power. The rotating armature (electric motor) is balanced on roller bearings so there is little friction or wear on moving parts. So whether you are motoring or regenerating there is no noise or vibration, absolute quiet! The electric motors today are designed to run 24/7, maintenance free.

 The electric propulsion system and batteries takes up less space than the ICE propulsion systems fuel tanks, transmission, exhaust system and the cooling water intake. Since the electric motor turns in both directions you have no need for a transmission or the maintenance of a gear reduction unit.

Comparing the whole weight of electric propulsion to the diesel systems, including all batteries, generators and fuel has the electric drive system coming out lighter depending on the size of fuel tanks and fuel load. The original cost of converting to electric propulsion is equivalent to the diesel upfit.

Electric Vehicle Concepts electric propulsion systems for motor yachts that will run 24/7 will require an on board charging system. Most all power and sailing yachts come equipped with onboard generators more than capable of recharging your propulsion system battery storage for constant running. In most cases smaller gas or diesel units are sufficient.

Most E-V Concepts electric propulsion systems are design to propel your yacht for two hours average before recharging. Recharging can be accomplished in 20 to 30 minutes. In many systems two separate battery packs are used. Using one battery pack for propulsion as the other charges and runs all other house appliances.

Electric Vehicle concepts high-speed cruisers have the option of running a hybrid propulsion system. Much like Electric Vehicle Concepts electric cars have used for the last 30 years. In this drive system the ICE generator and electric motor can be coupled together for use of higher speed propeller ratios. With your larger battery storage you can now run all your air conditioning and other conveniences day and night without using your generator for weeks.

You will always have the ability to charge your battery storage at dockside or take advantage of the unused roof space for solar panels or possibly a couple small windmills. You may never have to run your backup generator. Would you rather not hear, smell and feel your generator as you relax or sleep.

 Electric Vehicle Concepts has dry-dock storage for 70 ton and up to 80 foot yachts and deep water slips for all conversions and any regular yacht maintenance. Our facilities are located in Charleston, South Carolina on the intra coastal waterway. 


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