I have had the moultrie game spy 35mm, and then the 4.0, and now use the 4.0 and 6.0 IR. And I have learned the hard way that the cheap and rechargeable batteries just aren't reliable. I have used energizer and duracell without any problems. They'll last twice as long if not longer. I've also used the solar panel, but they have to be rechargeble batteries used in the camera. And even though it helps it's still not as reliable as just using energizer or duracell batteries.