Need help finding parts for powering an LCD screen(with diagram!)

[Jakehinds]

hey guys, I'm trying to use one of my dvd players that plugs into the car cigarette plug so i can see what i've filmed with my GoPro. I've put it together roughly, and it is working, unlike many of my other projects.

what I'm using to power it is a battery for an old car dvd player(not the one i have now) but the thing is, is I can't recharge it once it dies. I'll be posting pictures to show what i need.

I have an ac plug for some old walkie-talkies that has the same coaxial plug(the plugs with the yellow ring around the tip, not for TV's) as the battery i was talking about. They are both male, and what i need to know is what type of coaxial size this is and do they make female to female coaxial adapters that are the same size on both ends? If you dont understand this or my diagram, just leave a comment.

The reason im not just using the wall plug to power the screen is because whenever i film, its outside with no outets.

 

[CocaCola]

A 9v @ 210mA wall wart is not going to power something that wants 7.4V @ 3600mA... Or is that 3600mAH? The difference is significant...

You will need a new power supply that is 7.4V @ whatever current you need + 50% or so, as for the size of the plug, you need to measure inside and outside diameters, there is no universal size...