On Mon, 3 Jul 2006 20:39:07 -0700, "Duffer2"
wrote:

Thinking about installing a 2000watt Power Inverter to run a 1000W (1350W @
120vac consumed) microwave oven and to heat my hot water tank 1200W @
120vac not at the same time.

Or to use a 2KW portable generator.

When heating the water, I estimate that the run time is about 20 minutes to
achieve max temp.

I'm wondering if my house batteries could handle the additional load of an
inverter.

My boat has a 300HP outboard with 60-70 Amp alternator (i cannot increase or
change the alternator)

help is neeed for an old "Duffer"


You need to consider the size of your house batteries plus another
important item.

Considering inefficiences, you're talking about using maybe 40 amp
hours to heat the water. A 4D (183 Amp hours and 130 pounds) ) or 8D
(225 Amp hours and 160 pounds) gel cell would probably be adequate.
You would need to run the engine almost twice as long as you run the
microwave to recharge.

The other item is that unless you spring for some really big bucks,
inverters do not put out a real sine wave, and microwave ovens seem to
be sensitive to that. Power output drops off, things overheat.

By the way, we burned up a coffee grinder and a power tool battery
charger using the inverter.

Our seagoing Winnebago has about 1000 Amp hours of house batteries and
we don't run the microwave on the inverter more than a minute or two.