Wire it up to run off a 6 volt battery. I ran my IR4 the whole time I had it out last year before season on one battery and it was still going when I pulled the cam from the woods.
I have 2 of the IR4's and love them!! They have awesome battery life!! I put mine out and leave them for 2-3 months and they still have 1/2 to 3/4 battery life!! Great camera for the $$$!