Great review! Well done 
Yes, but the low alert voltage will be different for the wk41 ( around 3.45V and 1.1V ?) and for wk42 (3.45V and 2.8V?)
No idea. I used my lights for mod hosts so no longer have the original drivers installed to test.
Incidentally, the AA sized WK41 and the CR123 sized WK42 have what appear to be identical heads. The battery tubes are also the same width. The only noticeable external difference, other than the labeling on the bottom of the head, is that the WK41’s battery tube is longer than the WK42’s.
Note that the AA sized WK41 is no skinnier than the CR123 sized WK42. Both lights are identical in width.
I could be missing something or it may be over my head entirely.
But since 16340 and 14500 batteries are available in equal voltages and capacities, and both the WK41 and WK42 are set up for the same 0.9-4.2V working voltage, wouldn't regulation be the same no matter if you were using a 16340 or 14500?
Even a standard alkaline or NiMh AA battery would work with the same working voltage of 0.9-4.2V working voltage range of both the WK41 and WK42, right? Or no?
I agree. It makes sense that both the WK41 and WK42 would have identical heads with identical drivers. The only functional difference being the battery tube length.
However, since I’ve modded my lights I can’t personally test that.
Hello!
(please excuse my “bad” English, I am writing from Germany)
I am intrested in the WK41 light and now I am wondering if it is possible to use this flashlight with some kind of selfmade “adapter” with the CR123 Batteries?!?
As quoted the size (besides their lenghts) of the WK41 and WK42 are the same - so it must be possible, or?
Has anyone tried to do this?
Would be great get some help!
Thank you very much!