Will flat top 18650 batteries work in Fenix lights?
Most modern Fenix flashlights will require a button-top style 18650 battery but some older styles may not be compatible. As a general rule, assume that any light that came out after 2017 will require a button top battery and that any lights that came out before that will need a flat-top. This is not a hard-and-fast rule and there are many exceptions but it is a good idea to think of it in these terms just to ensure that you are getting the correct battery for your flashlight. If you have any questions about a specific model please contact our customer service department via live chat or email.