[jsundin]

You are definately an engineer. My dad had a cordless drill (12V) that he could no longer find batteries for, so he connected a car battery to it, creating a much heavier cordless drill setup. I am trying to imagine your setup, with a car battery, an invertor and an AC connection to the camera.

Pentax users will be in great shape!

[leaton]

You don't need an inverter. Just a battery and cord.
I'm with you're dad. Bet he could build a new deck before the battery died!
I just looked around and someone has something like what I mentioned:
http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=919

Looks like it should be able to run just about any kind of camera.

[Arpe]

I didn't think it was voltage alone that would be the decider (I'm definitely not an electrical engineer), doesn't current have something to do with it too?

[leaton]

Yes - current does have something to do with it. However
current only has to do with capacity, or life of the battery.
Voltage is the main issue since too little will not get the job done, and
too much will blow out the circuit.
Think of it as Voltage = energy of the power and current = amount of power.

A river's speed is voltage, a river's size is the current capacity.

[Arpe]

That's funny because I always equated a river's current (speed) to the, well, current!! That's no kidding, I often use the water anaolgy for electricity, even though they shouldn't mix. And I thought the amount of water was voltage. Damn!

[jsundin]

Here it is, about 3 weeks later and I am using the same set of lithium AA's I put in the camera. I have shot about 1800 shots and it is still going strong on the same ones. Once they die, I may see if they have enough life to power a flash unit, or my wireless mouse for awhile.