I just received a 3 battery holder (CR123A) from blade-tech. It slips onto your belt and allows you to easily and securely carry 3 spare lithium batteries at all times. I am going to combine it with my E1e KL1 in case of trouble on the tube. I figure that if I don't mind the light getting dim, that gives me 200 hrs/8 days of light!!!! /ubbthreads/images/graemlins/grin.gif /ubbthreads/images/graemlins/grin.gif