(07-27-2012, 12:28 PM)PaulaO2 Wrote: Depends on the battery and it's charge capacity.
We discussed this in the camping thread and the 'be prepared' thread. I think one guy could get 5 nights out of the battery situation he had.
If I can find my volt meter, I'll do a test with the battery I've got. I know the meter is around here somewhere....
If you can get even a couple nights out of the car battery and still be able to start the car it would be great for car traveling. Even if you're staying at a campground for several days you could always use the car for a side trip every other day or so to charge the battery back up.
As for the connector, my vehicle has a cigarette lighter that works when the ignition is turned on, plus dedicated cigarette lighter socket that is always on. All I would need is a plug to go in the cigarette lighter socket (cannibalize from a cheap cell phone charger), and a socket to go into the CPAP, which can probably be found at Radio Shack or equivalent. The tricky part is figuring out which wire is the positive and which is the negative. Figuring out the cigarette lighter wire is easy with a meter, but the wire going into my CPAP is solid round with no way to tell which wire is which.