CR123A out put question

2 of my lasers came from O-Like equipped with RCR123A 3.6V 800mAh batteries.
now looking for replacement batteries I can only find CR123A batteries which are a single use battery not rechargeable.
I've also noticed that the CR123A batteries are 3V not 3.6V.
so is this normal?
is the extra .6V something unique to rechargeable batteries?
I have put an "ENERGIZER LITHIUM PHOTO" 3.0V in my 150mW "Cute" Laser,
it appears to be as bright as with the 3.6V battery...
although the "Energizer" battery seems to have some contact issues and needs a little shake from time to time to achieve full brightness.

You're looking for 16340 Li-Ion batteries, places like DX sell them. They're the same size give or take a millimeter or two, but 3.6v and rechargeable. However, and this is a warning, right off the charger they can be 4.2v, so make sure your laser can handle at least 4.2v in to be on the safe side.

They should be fine to use if the laser came with the same kind of cell. As Proto said, rechargable CR123 (RCR123) is often used interchangeably with 16340 (16mmx34mm, 0=cylindrical cell)

You do have to keep an eye on the voltage, though. If your laser came with a 3.6V RCR123, get a 3.6V RCR123 replacement, because there ARE some Li-Ion cells that have circuitry to drop the Li-Ion voltage to ~3V.