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Old 08-31-2014, 01:43 AM   #7
FlyWright
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City: California Delta
Vessel Name: FlyWright
Vessel Model: 1977 Marshall Californian 34 LRC
Join Date: Apr 2008
Posts: 13,728
OK, I'm going to provide a different minimalist view of inverter operation. My boat is almost identical to yours except I have no built-in generator. I have a 34 ft Californian designed for 12V and propane in the late 70s.

I have a Honda eu2000i gas powered generator. I have a 1000W inverter which delivers power to one countertop of appliances through a dedicated line and completely separate from the boat's 110V system. No transfer switch required, but I plan to install one soon to minimize the switching of power strips to the needed plug outlets.

My stove is propane, heat is propane, #1 fridge is 12V/110V that switches automatically, #2 fridge is 110V only (my major power pig), Kurig Coffee is 110V (1500W, gen only), Mr. Coffee is 110V (600W and inverter or gen capable...you can tell I like coffee!) and my microwave is 900W (inverter or gen capable). My water heater is 110V shore power or stbd engine powered. I have a 120A alternator on my stbd engine, so when I heat water, I'm providing a good charge to my house bank.

Like you, I had 3 8D batteries, one for start of both engines and two dedicated to house use. I replaced the 2 house 8Ds with 6 golf cart wet cells as you described. I gained a 50% capacity increase in the identical footprint of the 8Ds.

My #2 apartment size fridge requires approx 90-100 AH +/- per day. My total daily need is 175-185 AH/day. I use my stbd engine to provide hot water since it's not really efficient to run a water heater on an inverter.

To live onboard with BOTH fridges operating, I need about 5 hrs of gen operation with my 55A shore charger to meet my daily needs. This comes in the morning, afternoon and evening when the battery needs are the greatest and the charger provides the most output. If I move the boat, I gain charging through the alternators, reducing the Honda gen operating needs. As the batteries approach 80% charge, their acceptance rate decreases to the point that I can't get more than 10A/Hr into the batts. So the gen time is best utilized providing higher charge rates and I live between 50% and 80% on the charge curve.

If I had a built-in gen, I'd keep it, even if it was pickled for future use. I would not remove capabilities if not needed. If your needs change in the future, you could always recommission it.

My recommendation would be to get a Kill-A-Watt AC meter and a DC ammeter and determine your true electrical needs. Buy the Niger Calder book and study it closely. Then, when you have questions, post them here. Please keep us posted!!
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