On Tue, 07 Mar 2006 17:00:47 GMT, "Gordon Wedman"
wrote:

Now 100 amps at 12 volts may look
like 1200 watts but the chargers are not 100% efficient. I think they draw
something like 30 or 40% more power than you would think.

It depends on the power factor of the charger which is a measure of
how much of an inductive load it presents to the generator. An
inductive load causes a phase shift between volts and amps which has
the effect of increasing power demand as measured in KVA.

In addition, the wattage at 100 amps is actually 100 x 14 volts, not
100 x 12. So you are starting out with a requirement for 1400 watts
further incerased by a power factor of 50 to 90% depending on the
charger. Using a PF of 75% as average, your wattage requirement
becomes 1400 / .75 equaling about 1900 watts.