Battery maintainer?

I like having the choice. I wired the live socket to a switch, in case I need it shut off. Some things need to stay on when the car is off, I've found.

 

I just put in a couple of dashcams and came across the use of dedicated batteries for use while parked. Some dashcam makers have their own, and they're expensive. Interesting if you could roll your own.

 

I heard a rumor that moving the fuse position changes it between live and switched, but I can't look because I don;t bend like that anymore.

 

I got one that has its own internal battery for catching people who mess with your car while parked.

 

Depending on what setting you choose, if drawing on vehicle battery while parked, your car might not start.
edit: I don't mean your car, just in general.