“Really useful product. What we do is put sets of Energiser ultimate lithium batteries, that have finished their useful life in the trail camera, into the external power-pack (they are still at 1.6 - 1.7 V, though you should check with a multimeter). We then deploy the power pack when another trail camera is showing the first signs that its batteries are getting tired.
We then seem to get an extra 2-3 weeks out of both sets, averaging 60+ 20s night time videos per week. By this point both the batteries in the trailcam and in the power pack are absolutely knackered (1.3 V or less)! This has saved us a quite a lot of money over time.”
