AA light with a big head

These guys are right, the X5 needs a lithium-ion cell.
The Manker T01 works with regular 1.2-1.5v AA:

Currently sold out at Banggood — called GODMES T01
Currently sold out at Gearbest — called Manker Quinlan T01
and I don’t see it listed at Manker: http://www.mankerlight.com/