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nimbusgb nimbusgb is offline
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First recorded activity by BoatBanter: Jul 2006
Posts: 16
Default Water driven DC generator

Amps per day is a nonsense and meanigless unit and indicates a
complete misunderstanding of the principles involved.

Amps may be helpful when looking at an instantaneous situation. A
constant 5 amps into 13.8 volts would be enought to run the nav
instruments , radio and some of the load required for a fridge or
autopilot. A seemingly 'free' source of energy but to get the 69 watts
( 5 * 13.8 ) the system ie propellor, gearing , alternator, charger is
unlikely to be anything more than 20% efficient so around 350 watts
are exerted as drag on the boat, about 3/4hp. A worthwhile sacrifice I
would say.

To make sense you need to convert to amp/hours or watt hours.