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Old 05-19-2008
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Installing 700 Watt Inverter

Intended Use: Recharge laptop, maybe run small coffee maker. That's it.

Background: I have a 150 Watt West Marine inverter that kept cutting off last season when the laptop was charging. Since the laptop power brick gets hot in proportion to the laptop battery level (real hot the lower the charge), I thought that it may be drawing quite a bit of juice and exceeding 150 watts. Since power = voltage * current, that would be about 12.5 Amps (150 watts/12 VDC = 12.5 amps). This is an enormous amount of current (I don't recall what my ammeter read) for a laptop to draw, so I now suspect that I'd drained my batteries below the inverter threshold, EXCEPT that I was on shore power at the time with the charger running, so it shouldn't have been an issue.

Plan: Since they're so inexpensive and to avoid inverter limitations, I just eBay'd a 700 Watt inverter that I plan to hard wire into the electrical system. All installation instructions that I've read call for a direct hookup to the batteries. Obviously, I don't want to do that and want to wire it to a spare breaker on my power panel.

Question to the Sailnet Wizards: Can anyone see a problem with wiring to an UNUSED breaker on the boat's electrical panel? Will the inverter work ok not being direct connected to the batteries? I suspect that the manufacturers don't want someone to use a cigarette lighter and its skinny wires to draw 700 watts so they recommend a direct connect.

Thanks, all.
Sabre 38 "Victoria"
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