Is there an EDC that can use all these batteries? CR123/Rcr123/AA/18650 batteries | Candle Power Flashlight Forum
Designed an 18650 to 2x D Cell adapter with charging for my Maglite. : r/flashlight
18650 to 21700 battery adapter
Aaa To Aa Size Cell Battery Converter Adaptor Plastic Aa Battery Storage Holder Battery Converter Case For Aaa To Aa Battery - Battery Storage Boxes - AliExpress