I store battery packs in the fridge for extended periods, never the lights. They are double ziplock wrapped, with dessicant chips in the bag with the pack. As my flashlight collection has grown, I now have 9-10 fairly expensive 18650 batteries too and I'm thinking of doing the same with most of them, leaving out 2 for instant use. I don't think I would store the headlights or flashlights in the fridge, there is significant humidity and even if stored in dry pack, I would be worried about condensation forming inside when you do take them out. Make sure to discharge batteries to 40-50% before storage.