I recently got a BYB Motion Sensor LED Night Light this has built- in rechargeable lithium battery that provides 4 hours of continuous light. The unit can last up to 2 months in "auto" mode (so it comes on only when motion is detected).
When the power gets low, just connect it to a USB port with the included Micro USB cable. The light comes on when you are within 3 meters of the unit, and will go out 15 seconds after you walk away. You have multiple options for mounting this light. Included with the unit are a built-in magnet, 3M adhesive tape, screws and mounting holes. 6 LEDs provide 100 lumens of light. And the LED technology helps keep power consumption low, which means more lighting with less charging. The LEDs bulbs last up to 75 years. And thanks to the rechargeable battery, there's no need to worry about removing and replacing batteries.
My Opinion: I really like the size of this night light it is so small and the size of a cell phone and easy to install on any surface with the screws. I think this will be perfect for camping this summer as it will last awhile in the auto mode and can be used as a flashlight at night as well. I really like the way it works and brightens any room.
See more at http://www.amazon.com/dp/B015MM9ELG
Disclaimer: I was in no way compensated for this review and this is solely my own opinion which may differ from yours.