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Old 06-14-2022, 09:53 AM   #9
twistedtree
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City: Vermont
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Quote:
Originally Posted by ScottC View Post
- accept low speeds. Running 3-4 knots will extend your electric range significantly vs. running full-speed on electric. (Why? Peukert's curve. https://www.victronenergy.com/media/...-exponent.html



One quick clarification. The Peukert effect from heavier power loads on batteries is overwhelmingly a lead-acid battery issue. With Lithium Ion batteries, the Peukert exponent is essentially 1 so there is little effect on battery capacity within the range of intended use.


The gain from going slow in a boat is because the energy required to move the boat increases by the square of the speed. So doubling speed, say from 3 to 6 kts, will require 4 times as much power. You will get to your destination in half the time, but it will take twice the battery capacity to do it, i.e. 1/2 the nm/kWh of stored energy.
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