On the matter of lithium primaries - I have a few Utorch UT-01’s that I’m very fond of, and they also won’t accept FRESH lithium primaries. My work-around is to run the cells for 10 or 15 seconds in another light to “blow the foam off the beer”, after which they run fine in the UT-01. I have an old Fenix light that I have to use the same trick with.
It seems like that initial 1.8 v is a spike that very quickly reduces itself to 1.5 or 1.6v for the remaining 99.9% of the cells capacity. I don’t know if that would work with the T4, but it might be worth a try.
So, while I’m waiting for the MAO version to come out, is there a clear-cut best emitter for this light (especially high CRI versions from 4500K to 5000K? Floody lights (or lights that I can make a bit floody with DC-fix) with that CCT range and 90+ CRI seems to be my jam.)
I like the 5000K LH351Ds in my Sofirn SP36. I know that the 219B 4500K is well-regarded by many, but is a bit rosy-tinted and dimmer than the rest. The newer 519A 4500K is supposed to be really good as well, but I don’t have any lights with it yet, so I can’t compare.
I have the LH351D 5000K and really like it. The beam is pretty neutral, and the green AR coated lens definitely reduces the typical greenish hue of this emitter. When compared side by side with my SP10 PRO with the same die, the T4 hotspot appears to be much closer to bbl.
For floody high CRI between 4500-5000K, get the 519A 5000K. High CCT 519As tend to be 300K warmer than rated, so you’d expect around 4700K in practice. The higher R9 and better tint will make you want to toss the LH351D in the bin. Although rated at 90CRI, 519As seem to be consistently above 95 and average 97+.