Fenix arb l18 rechargeable li ion battery 2600mah lithium the next generation of 18650 batteries are here introducing the top of the line fenix 18650 battery an amazing 2600mah rating fenix has increased its emphasis on safety by building in features to prevent short circuits and design multiple layers of protection the new button top design better accommodates a variety of flashlight brands fenix continues to be an industry leader in lighting and battery innovation specification