"Bob Engelhardt" wrote in message
...
HF has a "700w" inverter that runs from a car battery. It is "700 watts
continuous for up to 30 minutes" and has "Auto battery cables and 30 amp
fuse". Is this new physics? Old physics held that 12v at 30a was 360w
and you couldn't have more watts out than watts in. This is even worse
than "Sears horsepower".

Your average store-bought UPS has the same deal. In the outside of the box
they are always rated in "VA" rather than in watts. If you bother to read the
fine print, you will find that they assume a ridiculous power factor and your
500 VA UPS is actually a 250 Watt UPS.

Vaughn



Bob