"Shaun Van Poecke" wrote in message
...
I'd be really interested to know how much power peopleare using
on their boats. It neednt be too exact, though it would be nice
if you had some real Ah figures, but just generally what size of
battery bank you have, what you use on a daily basis in terms of
power, and how often/how long you need to charge for.

40ft sail yacht, daily consumption, Mediterranean, summer:
35 to 50ah for fridge, depending on outside air temp.
40ah for nav lights over a full night watch.
20ah for autopilot going to windward, 40ah going downwind in
rough weather.
20ah for all the rest - lights at night, instruments, radio, CD

Amelioration:
Solar panel (60w) 25 - 30ah

Capacity: 600ah

Policy: discharge to 66% max (200ah)

Outcome:
Voyaging: re-charge every 48 hours with 3hr engine time, or 6hr
genny
Day sailing: motoring in and out of harbour suffices (45min a day)
Harbour time: plug into power, or run genny 1hr a day

Detail:
Engine, 100a alternator, smart charger
Genny, 240v 2kw petrol, via smart charger

Strategy:
If you're travelling by sail, you often need the engine enough to
cover all your needs. Fit an AH meter to keep track of what's
going on. The occasional discharge to 50% is acceptable, going
lower is going to affect your battery life. Even so, replacing
batteries yearly would be a damn sight cheaper than fitting and
running a diesel generator!

--
JimB
http://www.jimbaerselman.f2s.com/
Comparing cruise areas within Greece and N Spain