DVD players and rear camera issues..Connected???

[elg13]

We have a 2011 traverse LTZ Bought it used. We have headrest mounted DVD players. Im not sure if they were after market or came with the vehicle. So after a few weeks of use, the DVD player would skip all through the movie and you would just have to let it run its course. The back up camera started going out around the same time. We stopped using the DVD players bc it was so bad. We ended up changing out the battery and then both worked PERFECT for a few days. Then after a bit of use, same problelms. Stopped using the DVD player and then the rear camera worked perfect for months! Tried the DVD players a few days ago for the first time in maybe 4 or 5 months and slowly the rear camera picture started to act up again (dark picture or no picture). I also noticed that my son turned an overhead light on and it was left on for several hours and this also seemed to effect the rear back up cameras picture quality. Im just wondering where they power source is from for these..im assuming its the battery?? So could this be a connection issue? Im hoping to get it fixed because we have a road trip coming up. I want to try and troubleshoot myself a bit before taking it in. I haven't looked at the battery bc honestly I wouldn't be sure what to look at or what to look for so im hoping someone could guide me. Im pretty handy with this stuff so Im comfortable with getting in there and looking around, I just need a little direction. Thanks!