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Archive for August 2010

Electric boat quote

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There are 2 typical conversion factors that are used around here. The first is 1hp electric = 2 to 3hp ICE (internal combustion engine). I prefer to use 2.5 for rough estimates. So a 12hp engine translates to about 5hp electric. 1hp = 750W, therefore 5hp = 3750W or 3.75kW. Alternatively, since boats are often overpowered or underpowered for various reasons, a more consistent conversion is 1kW per ton of displacement. The specs that I found on a Cascade 29 list it at 8500 pounds. That’s puts your power requirement right around 4kW.

So now you’re looking at a 4kW drive, probably with reduction, so far so good. Now, let’s look at batteries (storage).

A very general conversion to get you into the ballpark is 11.5kWh of usable charge = 1 gallon of diesel. Your 4kW drive will probably be 48V. A 12V battery rated for 240Ah contains 2880Wh of energy at a 20hr rate. Four of these batteries should equal 11.5kW (4 * 2880Wh or 48V * 240Ah). But this means running the batteries to 100% depth of discharge

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Written by anderson

August 26, 2010 at 11:13 am

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Eagle Cliff

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Myron and me on eagle cliff.

Written by anderson

August 22, 2010 at 10:51 am

Posted in Uncategorized