Originally Posted by marhen3530 View Post
Forgive me if my questions are dumb, I'm new to power supplies in a car. Do you only use this when an extension cord or accessible wall outlet is available, or do you use an AC to DC converter? Where is the best and/or cheapest place to buy these power supplies?
Yes you use with an AC outlet that you plug into is when you can use it.

This is an AC to DC power supply so it does the conversion for you.

Best and cheapest place is to buy it from Victor_inox here on the forum. PM him for details and pricing. I recommend getting the mounting feet for it as well for it's well worth it.