Post edited 9:54 am – August 3, 2011 by Steve Pooler

To run your unit on an inverter would take quite a bit of power…The basic conversion from 12 volt DC power to 115 VAC power is like 10 amp AC draw = 100 amp DC draw…And most inverter/systems are not 100% efficient so it's actually higher than that….Your system likely draws around 10 amps with fan & pump…Maybe slightly more with a hot cabin & warm seawater.

Also remember for just a couple of hours of cooling comfort…The system has to run for time prior to that comfort level…Which is added time & amperage draw…

Most battery manufacturers recommend not discharging batteries below 50%…2 hours @ 100 amps =upwards of 200 amp hours…So for that two hours of running you would need 400 to 450 amp hours of battery….That would be two big 8D truck batteries, or four 6 volt golf cart batteries (less space) 

As far as your head…I have run into this gal in another forum I visit…She goes by the screen name of Head Mistress and seems to know everything I used to know about heads, and much more…here is a link to her forum:

http://forums.sbo.sailboatowne…..y.php?f=31

Steve~

I will need the model # of the pump to get you an exact match…

I'm sending you an e-mail about the board…

Steve~