Consequences of using an 18340 battery in a CR123 light? : r/flashlight
26650 Battery Flat Top 3.7V Rechargeable Batteries + USB Charger for Flashlights | eBay
Amazon.com: Nitecore D4 Digital Smart Battery Charger for Li-ion Ni-MH Ni-CD with 12V DC Car Adapter, NBM40 18650 Battery Magazine & EdisonBright Battery Carry Case : Electronics