On Thu, 24 Feb 2005 11:46:01 GMT, Larry W4CSC wrote:

How many amp-hours are aboard to run electric blankets and the other loads
all night?

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It's not really a problem believe it or not. On our old boat the
house bank was 4 golf cart batts in series-parallel, total capacity of
440 A-H, usable capacity about 150 A-H. We had a 7.5 KW genset so
recharge was never a problem.

The electric blanket has a peak load of 300 watts translating to about
30 amps at 12 v. Duty cycle is about 50% on a chilly 50 degree night
in the north east. So for 8 hours of sleep we were pulling down about
120 A-H for the blanket (15 x 8), and maybe another 30 A-H for the
fridge. Never had a problem. The batts were 3+ years old when I sold
the boat and still going strong.

For the new boat (GB49 trawler), I plan a house bank made up of
individual 2 volt cells bolted together. It will weigh close to 1,000
lbs but that's not really an issue on a boat that weighs 60,000 fully
loaded. Total capacity will be over 1,000 A-H with usable capacity
greater than 350. Those 2 volt cells are guaranteed for 10 years so
they may turn out to be the last battery I ever buy. Recharge will be
via a high power inverter/charger, 20KW generator, and/or high
capacity alternators.