Runtime of Kx1B head on e1L body? Single CR123, instead of AA

I have both the E1L and E2Laa lights, and have swapped the head from the E2Laa to the E1L. I understand the only difference is the rated output and model numbers, and that they both utilize approx 3V input, but would the runtime be the same as when using a Lithium AA setup on the E2LAA vs using 1 CR123 in the E1L with the KX1B head? or Would the runtime be better using the 1 CR123? I have seen the reviews and runtime estimates with the Energizer L91 AA batteries at 9hrs plus, would the same results be achieved with the CR123? I appreciate any feedback. I noticed that the light looks much brighter when using the CR123 on the E1L, but I only run Eneloop aa's when using the E2Laa, so that is probably why it looks brighter to me



Thanks again.



Tony