I do understand the math P=IE! Another concern is recharging the battery
bank for the Inverter. I heard that my outboards have dual 70 Amp alternator
outputs, if so i should be able to utilize the second output for the
inverter battery bank?

My wire size requirement for a 3000w inverter is 4/0 with a 450amp fuse.
The distance of the outboards to the I-Battery Bank will be about 15-20
feet. I'm not sure what the size wire for the alternator output possible 12
ga. Should i increase the size of the wire for this run?

IF i donot have a dual outputs on the alternators what other options would i
have to re-charge the batteries underway?

Bill


"John Weston" wrote in message
. ..
Dennis Pogson, in article 5fbYf.4574$ic1.1629@newsfe5-
win.ntli.net, says...

I would have divided the 3000watts (AC) by 120 Volts (AC), not 12 volts.

That size of inverter at 12 volts will need a nominal 25amps when drawing
max power. Add on say 15% for loss on conversion and you would be looking
at
near enough 30amps.

Personally, for that sort of current draw I would be looking for about
500A/H batteries and massive section cabling dependant on how close to the
inverter you can locate the batteries.

You need to properly work out the likely maximum draw before working the
figures for required battery power.

Deep-cycle truck batteries are worth a look. Don't buy starter batteries
for
this type of application.


Dennis. Watts = Volts x Amps

Watts is power so you need the same power out as into the
inverter plus any losses in the inverters circuits. You can't
get more power out than you put in.

So 3000W = 12V x 250A or 120V x 25A I make it you'll need
250A (plus) at 12V into the inverter to get 3000W out

--
John