:thumbup::thumbup::thumbup::thumbup::thumbup:
This is the inevitable conclusion I cam to. I carry a Fenix E01 as my pocket light. Love it. Good enough light, and really long run time so in an emergency I don't have to worry about a two hour run time. I was carrying a spare AAA in a Bison aluminum capsule. Then I had the light bulb go on over my head. A big epiphany. The spare E01 is only a very marginal bit bigger, and the Bison capsule that carried the spare battery brougt it up to size. So I just put one E01 on the keyring as a spare light, and carried the other as my edc light to be used, in my pocket. That way, if the light went south for mechanical reasons, I still had a E1 right there.
Now I've been carrying the two E01's for about two yeas now. I like the system. When you get inot lights that small, it's easy to just carry a spare.