You can use standard 2xCR123 primaries or you can use rechargeables like 2xRCR123s or 1x17670.
On primaries, you will get about 60-90mins full power, then about 2-3 hours of diminishing output. The RCR123s will give you a bit more output, but less run time, something like 45-60mins full power, then about an hour of diminishing output. The single 17670 will have the lowest output, but its runtime will be similar to the primaries.
BTW: ONLY USE PROTECTED Li-On cells. This is because using unprotected cells the LED module will discharge the cells below 2.8v, which will damage the cells permanently.
A
good thread to read before using Li-Ons.
i have a question. i am about to order the bug out Cree Q5 Drop in module 230 lumens for my surefire 6p. do i need to do other things to support it or no? what batteries should i use? whats the runtime on it? replies are greatly appreciated