I use my outings for work and with the scouts as an opportunity to check, rotate and resupply perishables. While I carry new batteries, I will take the previously purchased packages and refill all of the electronics. I have a box at home where the replaced batteries go and we use those for everything around the house, still keeping a fresh supply on hand. All bags are emptied and repacked, including survival kits, before every outing. Everything is cleaned and resupplied upon return from any outing. It does require discipline, but that is part of what I am teaching the scouts anyway, planning,preparation and leadership. Old flares, tinders, and other perishables get used for training and practice. I am fortunate that my work allows me to use some of the old stuff that is being replaced for scout training, so I don't have to pay for it all.