I accidentally put a 14500 in the Lenser 5.2 that I had not modified to take it, and it destroyed the driver. (I fixed it with the driver swapped out of the other one.) So the 5.2 can’t run with a lithium cell like SK68s do. There is less difference between CR123a and Lithium ion than between AA and lithium, so maybe it will work, but as far as I know it would be a risk.