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DC to AC Inverting for boat Answered

This spring I am looking to build a pontoon boat from scratch (Besides the pontoon logs). Its going to be a large boat and I am wanting a few amenities to go along with it. Im trying to figure away convert the car battery wich is on the boat to power appliances such as mini-fridge, lights, radio, box fan, and maybe a PS2 with Television. I need a high wattage out-put to power everything too. For sure: 8 lights - 75 Watts ea. 20 inch tall Mini-fridge - 200 watts Stereo - 150 watts Box Fan - 120 Watts Maybes: PS2 - 180 watts 20" Television - 300 watts I want this to work if all the for sures were going at once. I want to know how many car batteries I will need approx for 10 hours (or longer) of use with the "For Sures" And I want a clean way of doing this. Any advice would be much appreciated!

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d_child (author)2007-11-13

Alright so I think Im going to buy a 120 amp 12V Deep Cycle battery. I read somewhere that rule of thumb for amperage is 120 divided the wattage is the approx amperage.

25 Watt CF Lights x 8 = 200watt = 2amp
200 watt fridge = 2amp
stereo = 2amp
box fan = 2amp

So lets say 10amps per hour just to be safe.

I get a 120amp 12V Battery should be able to keep the appliances on a stong flow for 12 hours. Well Im wanting to add a little bit more to this I found a 3V Solar panel that will charge the battery.

So now for my next question how logical is it to use that solar panel to charge the battery? will it charge the battery enough to maybe squeeze a few extra hours out of it? And about how much would it charge it during a 8 hour sunny day?

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NachoMahma (author)d_child2007-11-13

. For longevity calcs, you need to be looking at Amp hours. Amps are an instantaneous value. Same with Watts. . Remember, there will be inefficiencies/losses in the inverter, so it takes more than 100W of input power to get 100W out.

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Patrik (author)2007-11-13

For the fridge, you can probably find a large portable model that runs on 12V DC and uses a lot less power. Power consumption is a more important design criteria for a portable model, so it's likely to have better insulation. Plus you save some on the DC-to-AC conversion losses.

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d_child (author)2007-11-12

Here is a inverter can I hook everything up to this one inverter or is there a chance it will over heat? I will prob just run extension cords through the boat. And rig to exterior outlets with covers.

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NachoMahma (author)d_child2007-11-12

. Can't tell the rating from the pic, but that's what one looks like.

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d_child (author)NachoMahma2007-11-12

Its a 1500 it wont melt down or catch fire because its going to be in a fairly enclosed area so that it wont get wet. And all appliances can be plugged into this one unit?

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NachoMahma (author)d_child2007-11-12

. If it's going to be in an enclosed area, you may want to step up to a larger unit or install ventilation fans. If you do happen to run everything at once, that 1500W unit will be running hot. . Next to impossible to keep water out of anywhere on a boat. If not direct splash, there will be condensation. . Just make sure you don't turn everything on at once. And check and double-check your wiring, particularly the grounding. And use GFCI(s).

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d_child (author)2007-11-12

What do you mean by deep cycle batteries

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NachoMahma (author)d_child2007-11-12

. Commonly called marine batteries. Designed to be discharged further than car batteries.

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Here is some info on batteries, and the DEEP cycle and marine batteries mentioned: Link to Battery info - Go Deep !

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deep cycle (also called marine) batteries have thicker plates than car batteries, so they can stand repetitive charging cycles.

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NachoMahma (author)2007-11-12

. A car inverter should work for everything but the Maybes. Might need cleaner power than most cheap inverters put out for the PS2 and TV. . A 1500W inverter will probably handle everything - go with a 2KW for some reserve.

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Tool Using Animal (author)2007-11-12

one to two deep cycles (car batteries will die from the cycling) and pick up a cheap car inverter with the batteries, 1500w one costs about $50. Use CF bulbs and increase your margin.

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