External Battery for Trail Cams

[DRhunter]

Just wondering what everyone's experience with external batteries are for game cam's. I have a couple of Spypoints and am hoping to have battery power in cold weather and for a couple of months Oct-Dec/Jan. In my experience the normal AA freeze up just south of freezing mark. In particular I am looking at the Spypoint 12volt 7.0 rechargeable battery.

Any experience on how long these hold charge, do they hold up under cold weather, does the battery life decrease after several charges? Any other info would be great. I also know that several people have suggested using disposable lithiums, however I am just looking at experience with the external before making the decision between external and disposable lithiums.

Season is coming up shortly, happy hunting all!