# Electric outboard for 20' x 6' flat bottom skiff?



## YotaTruck91 (May 25, 2015)

I'd like to design an electric outboard for a flat bottom skiff that will be able to transport my entire family (two adults, two kids, and a dog-about 600lbs total) around local electric only lakes. The design of the boat will not be the most efficient, because the primary concern will be carrying the weight of the crew, batteries, etc... Basically I'm looking to bolt a 15HP golf car motor:

This one? http://www.evdrives.com/product_p/mot-me0709.htm

to the lower unit of a conventional outboard so that I can hang it off of the back of the boat. I thought about doing an inboard, but given the fact that I want to be able to beach the boat and operate in very shallow water, plus be able to mount a conventional outboard from time to time, I think the electric outboard idea is a better one. Mounting the motor is pretty straightforward-my biggest question is how much battery capacity do I need/can I realistically take with me? 

The motor I referenced will operate between 24 and 72 volts. I figure at most I can carry eight batteries wired in series parallel, giving me 48 volts at however many amp hours each bank combined will bear. Will 48 volts be enough? What do I need to take into consideration as far as gear reduction in the outboard leg? How can I figure out how much runtime I'll get out of a given amount of amp hours?


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