Can I use Duracell batteries in my Fenix flashlight?
With lithium-ion batteries, we don't recommend using anything other than Fenix batteries. However, you are able to use a Duracell 18650 battery with many Fenix flashlights.
With alkaline batteries, we do not recommend using Duracell batteries within our flashlights since the Duracell batteries release a gas and our lights are waterproof. there is nowhere for the gas to go and that leads to corrosion.