# Electric Motor for my Draco 2500 25ft Sports Cruiser



## Nemersis (Nov 22, 2020)

Hi

So, have the boat, just the shell, no engine at all, in the past these were powered by 2 x 140 HP Mercury 3,0 engines (170kW) 


Am wondering if possible how to convert to electric power, probably need much less power as aiming it at a chug along gin palace river boat rather than high power off shore ability cruiser.

Anyone able to suggest if this is a.... possible and b....practical at an affordable cost

Cheers in advance











Photo for illustration purposes, boat in photos is same as mine.


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## remy_martian (Feb 4, 2019)

Running at full power, the largest Tesla battery pack will run for about a half hour, lol. Boats suck for electrification unless you severely underpower them. 

So you can work your electric motors' horsepower backwards from there...run for an hour on two 70hp motors, etc....on a $14,000, 1200 pound (iirc) battery pack. I'm not a nauti engineer, so can't tell you what the speed/horsepower relationship is and am too lazy/busy to look it up.


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## brian_ (Feb 7, 2017)

Getting boat up on plane takes a lot of power, which is why the boat has two significant engines. If a boat stays below the "hull speed" (which depends on length and might about 7 knots for this size), the power required to keep moving is quite small. This style of hull (designed to get up on plane) will require more power than a proper displacement hull (like a sailboat or ship), but it should still take only a few kilowatts at this size. That means hours of cruising on a salvaged electric car battery, and a wide choice of possible motors.


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## remy_martian (Feb 4, 2019)

You mean trolling....


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## brian_ (Feb 7, 2017)

remy_martian said:


> You mean trolling....


If you're fishing, yes, but in this case:


Nemersis said:


> ... aiming it at a chug along gin palace river boat...


Running slowly in normal operation doesn't need to mean giving up the ability to make a burst of high speed on-plane... just acknowledging that for useful endurance most of the time the ride will be slow.


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## [email protected] (Nov 5, 2019)

This is a good perspective of weight and horsepower. The donor boat was under 2000# including a 3.0 motor. This combination seems to work but, as others have said, the weight of your boat will take a lot more HP and battery capacity.




Good Luck!


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