OK, Jennifer from Klarus finally responded back last night and confirmed that they are authentic Klarus batteries.

Now I have a new problem, I was not able to fit either battery in my Solarforce L2P body. The Klarus battery appears to be slightly fatter than the Trustfires, which fit fine. The body I happened to test the two batteries in has what seems to be a seam that may be sticking up and preventing the battery from slipping in (I could force the battery in, but then I’m afraid I might cause a short condition not to mention having trouble getting the battery out to charge it), have to see if they fit in my other L2/L2P bodies (I use an L2 at work and it doesn’t have that same seam). Looks like I will be trying to find a way to hone at least one of my lights to fit the new batteries. :person_facepalming: Not sure if those brake cylinder hones can go that small.