Not made for 10440’s, at most it may survive (these Yuji leds are tough), perhaps the boost circuitry will blow, but what certainly will not happen is a lot more light, these are simple 5mm leds and will not go much over 10 lumen.
Here’s the thread.
https://www.edcforums.com/threads/123a-v-aa-myths-and-reality.75472/page-2#post-92668, 4
It’s intent is comparing battery types, but check posts 25, 27 and 28. Not just stories, but real world tests.
^ He tested submerged alkaline batteries but not unpotted driver electronics, he just states that the light keeps on going because of the potting, he can not test that with an unpotted version of the same light of course. This is the case with all potting stories, there is correlation but it is difficult to prove that the potting is the direct cause of the performance.
My statement is that if the water is clean enough to keep the battery going, it is also clean enough for the electronics and led to keep going, at least with a simple driver like in the C01.
Being a city guy I have no Mt Washington in my backyard to change out batteries in a freezing cold river, so I will have to do with a kitchen experiment. Here’s the electronics of one of my C01 samples clamped on top of an alkaline battery (soldered a wire from the bottom of the battery to the driver) and dunked in a cup of tapwater. Admitted not all Sofirn’s potting gooey could be removed so that could still protect the electronics, but it will have to do for now. The video has breaks at various times but there’s timer to see how long it is running. I took the light out of the water at the end of the video and it is still running fine on my desk this moment an hour later.
Thanks for the test djozz. People seem to think that potting is inherently valuable. In reality, potting is only valuable if it ADDS something. As you’ve shown in your testing, the C01 can be physically robust, and even still work under water, without potting. So, it seems to me that potting may be redundant, and would add a possibly unnecessary cost.
Thanks David for understanding. Potting may still add something, I’m just beginning to think that also without it a small simple flashlight like the C01 will have the level of performance that we would like to see.
Btw, the current situation is still that the C01 will be potted, and that Sofirn has promised that it will be done well.
The 5600K C01 internals attached to the AAA was still giving light on my desk hours later, and it is weekend, and I’m postponing going out to buy and then cook supper for the family, and I like goodlooking experiments, so I dunked the assembly back into the water and see what gives up first, the battery, the electronics or the batt+ electrical contact surface (external illumination by the 3200K C01 sample)
Btw, Amsterdam tapwater has a conductivity of 550 microSiemens/cm, that is a resistance of 2kOhm/cm, the AAA is 4.4 cm long so from minus to pluspole is 8.8 kOhm, with 1.5 V that produces a current of 0.17 mA, draining the battery in 220 days.
So if there is no other route for a short than through the water, the battery draining by powering the electronics and led will be 50 times as fast as by the conductivity of the water.
Edit: this is not correct of course, the batt+ and batt- are much closer together on the driver, maybe even a single mm. In that case the battery already drains in 5 days through the conductivity of water, comparable to the runtime of the led.
parkerdude (1323) - 0; 3
Will they work OK with NiMH rechargeables ?
Yes, no problem with those.
Na, I think Vaalserberg isn’t a good substitute.
Hey, no messing with our Vaalserberg, have you ever cycled the full 322 meters up there?, this is a proper dutch mountain. And the fact that we have to share the Vaalserberg with 2 other countries does not make us less proud of it. 
I’m in for two of each.
I live at 600 odd meters the highest within 10 km is over 1000m. I cycled that one. Count this?
(great song!)
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Ok, you win, I never cycled 1000 meters up a mountain. Thanks for the NITS video, I know the song from way back but never saw this video before 
Btw, something started corroding in there, electro-chemistry on the boosted voltage side, brown stuff appearing and bubbles :partying_face:
I can’t watch the video where I am, but I suspect the tap water is becoming more conductive as the test continues due to some metal electrolyzing into the water and onto other components and parts. If true, it might accelerate until you get failure (sooner than expected).
Yep, you seem correct 
, it is in there for 3 hours and more and more brown stuff is forming, it actually floats up and forms a brown layer near the surface. Works quite nicely as a warm filter, I measure 3300K when measured from staight above the cilinder . I better stop the experiment now before everything is corroded away. So it was not any of the predicted reasons, drained battery or failing electronics or the battery contact point, that stops the experiment but corrosion did it :student:
Thanks for the extensive testing!
Thank you djozz for your reply and video test, very interesting stuff!