on the covert's go to your menu, got to the "NET" tab and select "Dowlaod FW" that will update your firmware. It will increase battery life, and sensitivity. You can also adjust the sensitivity, which is based on temperature. I put mine on the highest setting in these warm months, but hopefully soon I will be able to switch it back with cool temps coming. If you have any problem with coverts you can talk to a red blooded American who help diagnose and fix your problem. We are running 9 now and have had covert cell cams for 4 years and have only had to send 1 back. The new one was in my hands before the bad one one even got to them.
My neighboring leesor purchased a spypoint and he cant get more than a week to ten days of battery life. we routinely get a month and half or more out of coverts. but keep in mind, if you cant get cell service in an area, cell cams wont get service either. we have little pockets on our farm that get no service and we use the MP8s and the browning cams in those areas.