Hi,
Camera battery at night is your stamina during the day - if you're low on stamina, you'll have low battery (it's just visual representation of your stamina value in form of a "battery" at night)
The other issue - "game freeze" is simply a bug that has been already fixed, you can find the 0.4.3.2 build on devs SubStar page and get it for free, no idea why he didn't post it here.
Cheers!