Anyone use a power interver?

[ChuckE]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>a 6A drill at 120V AC = 70W <HR></BLOCKQUOTE>

No, those numbers are not correct. A 6A load at 120vac is approximately 720W, not 70. But perhaps you mistyped 720 as 70, so let me assume you meant 720W.

Watts remain somewhat constant regardless of the voltage you need to acquire it. A 12 watt light bulb running at 12v requires 1 amp (current, the amps, = watts / volts) would only require about 1/10 amp at 120v for the same amount of power.

Here is a real quick check. If the voltage is one tenth (120 vs. 12) then to get the same amount of power would require 10 times more current. Stands to reason doesn't it?

If a 6A draw at 120v needed to be converted to 12v, the current draw must then be 10 times more. So what was 6A at 120v would be 60 amps at 12v.
NOTE: Again this is very, very rough, because it doesn't figure in any of the inverter inefficiencies.

Here is a useful website for calculating various electrical related values, Formulas.

But, really, reconsider what you really need such a powerful inverter for. In my van I had a 200W inverter in it, for those few times I needed to plug something in. Not power tools mind you. Listen to H2Finally, if you really need to run drill motors and such, consider getting rechargeable DC powered tools. That way you aren't tethered, nor wiring up heavy wires to an industrial strength inverter.