Brightest would be the L2D Rebel 100 with the L1D body. I actually have this combination. I use it in 2AA mode because the turbo mode is soo much brighter then turbo on a single AA. But if you go li-ion, then go with L1D-CE as the rebel might not handle 3.7 or more volts. Or go with another brand for li-ion only use. For regular or rechargeable then the L1Ds.
I think that the initial post was referring to standard Alkaline and NiMH rechargeable, and for these batteries, I agree that the L1D/L2D Rebel 100 is on the top of the heap right now. With either one or two standard 1.2 - 1.5 volt batteries, this light is awesome, and the option to use the 2 cell battery tube with it's longer run times in low and higher output in 'Turbo' is also really nice.
Maybe I shouldn't have been so hard on Fenix, because their silly 'jump through the hoops' game with having to convert an L2D Rebel 100 into a L1D Rebel 100 will cause some folks who otherwise would have never noticed this useful flexibility to check it out.
As you pointed out, you are not only getting one of the brightest lights on the planet using 1 standard AA battery, you are ALSO getting probably the brightest 2 AA light on the planet at the same time
I also agree 100% with your comment that the Rebel could possibly be an issue with 3.7 volt cells, but frankly these cells should not be used in ANY L0D or L1D/L2D light even with the CREE emitters, because some of the recently manufactured CREE X-Lamp LED's also have lower Vf values which could cause problems even worse than the 'no low mode' problems reported. If you want to go with the higher voltage rechargeable Lithium cells it's best to go with the P3 style light which has a higher voltage light engine.
As far as the comments that the CREE Q5 is "Quite a bit brighter than the Rebel 100 according to Chevrofreak's testing", I would have to say that this has NOT been my experience.
Though the Q5 can noticeably beat the Rebel 80 (which should only be compared to a CREE P4), I have found that the differences between the Rebel 100 and the CREE Q5 are much smaller, and often favors the Rebel for any of several reasons:
- The 100Lumen/Watt Rating on the Rebel is the
minimum spec (so the Rebel could be a little higher) and the Q5 minimum spec is only 107 lumens, so with a lucky bounce, you could get a Rebel that is brighter on any given day.
- The boost converter 'light-engines' in many lights like the slightly lower Vf of the Rebel and drives it better (not good for 'Direct Drive' at 3.7 volts though).
- To get the max lumens/watt you have to order the 'cool-white' versions of both the Rebel and CREE, but all of the higher power bin CREE's that I have seen have had colder [more blue] white balance than the Rebels. With the cooler [slightly bluer] color balance of the CREEs, you can actually end up with a paradoxical situation where the Rebel could actually look brighter, even when it is technically putting out a couple less lumens, because it's warmer white light is working more effectively with the eye. (the eye is not as sensitive to blue light).
The limited availability of the Q5 bin CREE's has created a certain 'mystique' surrounding them, but steering clear of the hype, I have found that the CREE Q5 and Rebel 100 are roughly on a par with each other, and that
either one can be a fine choice if you are looking for the best performance possible.