[quote=DBCstm] The MT-G2 at 2.97A is making 23.166 watts (2.97 x 7.8V from the 2 18350 under load) Dividing 23.166 by the 6.1Vf of the emitter yields an extrapolated 3.8A to the emitter. [/quote]
The two quotes above does not make any sense to me. Maybe im not following your idea of extrapolated..
If the tailcap reading is 2,97A, the emitter current is not higher. If the emitter current is 2,97A emitter Vf should be around 6,4V. Any extra voltage you are measuring are lost before getting to the emitter.
The MT-G2 should be "making" about 19,2W like I said (3A*6,4Vvf) (Vf reference).
De-domed XP-G2 R5 @ 4,27A vs domed T6 XM-L2@ 5,1A. Its quite obvious that the XP-G2 would throw better.
When you de-domed the XM-L2 you gained 54% in lux. If the XM-L2 T6 @ 5,1A had been de-domed it should see a lux number of about 64 lux (41,5*1,54) if we assume the same gain in lux. If you had used U2 bin, and driven the XM-L2 to its max (closer to 6A) it should be on level with the de-domed XP-G2 light @ 4,27A in terms of throw.
Question is, what is peak emitter current with XP-G2 and 20R cell? I have not tested that personally, but I would assume its below 5A. So if R5 XP-G2 an U2 XM-L2 were fully maxed out (domed vs domed de-domed vs de-domed) in the stock Convoy C8 reflector, XP-G2 would not throw much further (if anything further), but XM-L2 would output about twice the lumen (if not more)..
Point is, if you you drive the XM-L2 with just a little bit more energy than needed to drive an MT-G2 @ 3A. You could basically get the throw of an XP-G2, but with output quite similar to an MT-G2.
In terms of runtime, you could use a single 20R in the XM-L2 light which gives you about 1950mAh @ 5A. If you are not interested in peak output, just use a 2900mAh or 3400mAh cell instead in order to get good runtime.
In order to run the MT-G2 you need two of the Efest batteries. At 3A they are about 1380mAh (690mAh x 2), which is considerably less than the "low capacity" 20R cell.
Another thing is that with the MT-G2 light is that the low voltage cut off does not work , so unless you take out your batteries often and measure them, or keep very good track of runtime (which I find annoying) most people are more likely to only use 1000mAh if not less in order to not risk draining the batteries too much.
XM-L2 or XP-G2 with Qlite are close to idiot proof.
Just mentioning some of the pros and cons that have not been mentioned or discussed much in the thread...