If you have the nerd skills, you can hook up a Raspberry Pi with a computer webcam and run it all from a USB battery pack. You'd have to know how to configure the settings via Linux but it's doable and highly configurable. As far as off-the-shelf.... There are lots of questions to answer first.
1. is the camera inside or outside
2. did you need it to record video
3. do you have a wifi network in your RV or are you connecting to a camp wifi
4. do you need it to send you a notice if it detects motion
5. how much time do you expect the battery to last or can you plug into 12v
6. can you power it off of solar if needed
Here's an example of a camera set up to take pictures of birds landing at a bird feeder
Feeder Tweeter | Raspberry Pi
Linear Mode
