The There Are No Stupid Questions Thread

Would a 3v bulb / LED with a couple of wires attached work? Install the battery in a light and drain it until LVP switches it off, then connect a bulb / LED to it directly?

The majority of my batteries are unprotected.

Has anyone squeezed a sanded down carclo 20mm triple into a FWAA or TS10 (17mm triple lights)? How much light does one lose by sanding 1.5 mm off all around? I guess a lot?

I suspect that would work just fine. The LVP should drop the voltage enough to not burn out the 3v bulb. Depending on the LED it might take a while to get to 0. Some LEDs will (I think) stop pulling below a certain V.
A hot wire bulb would likely be quicker.
Or just put 2 of them in series and don’t worry about the 4.2v starting volts.
Or just use a 6v bulb.
All the Best, Jeff

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I have a technical question:
I have built a 46mm GT4 TA driver for 12V input/output. It works but the problem is that it continues to step down the brightness to a quite dim level. The battery check of Anduril shows me 3.2V even though I use four 40T batteries with 4.0V. So I suppose the flashlight believes that the batteries are empty and LVP reduces the brightness.
Can anyone please give me a hint how I could solve this?

I have been away from the BLF for a little while and it has gone through a serious change in the time ive been away.

I’m just wondering what these brighter numbers mean?

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The brighter the number, the higher the ā€œlikeā€ to post ratio.
In other words, those threads have more ā€œthanksā€ per post than other threads.

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I’m not familiar with that driver but I think it’s using a Zener Diode to reduce the voltage to the MCU.
I don’t know of an actual fix for this but a possible work around might be a voltage calibration.

In Anduril 2 you can do a voltage calibration and adjust the voltage +0.30v and that may help a little.

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Aaah, gotcha. Thanks

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Adding some salt may help, I would think?

Then you generate chlorine gas :smiley:

:⁠-⁠) Not that much overall - some 0.5 L of Cl2 off 1000 mAh charge, I figured. You can add baking soda instead to avoid it, but you probably need to add something that dissociates to increase conductivity. Distilled water would have the resistivity in Mohms•cm. Typical tap water maybe a thousand times less. Seawater probably some 50 ohms•cm

I thought about it some more. It looks like even in saltwater a 3000 mAh battery should take over 3 days to discharge at some 35 mA, and probably close to a month in tap water. I hope I got it right, but if so, that may not be the best of methods to discharge one in a hurry.

p.s. IDK anymore, maybe faster, considering that the distance between electrodes may be much shorter than the length of the battery…

A nail and hammer through the cell should discharge it more quickly. Just don’t forget protective gear such as shorts and flipflops.

I saw that in an informative video posted from The Ukraine, I think.

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:rofl:

Hello, fellows! I would like to know if using a low-drain battery (18350 - 3C 1000mA) in an S6 flashlight with an SFT40 3000K driver rated at 8A would be dangerous or if it would simply limit the maximum output of the flashlight. Thank you in advance!

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If the flashlight needs 8A, i think it’s better to use a battery with higher A than that… (at least 10A! or more… !?

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It would simply limit the output

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Yes it will limit the output, but it will drain the cell quickly , there will be quite a bit of voltage sag, and the cell will heat up quickly.

If you intend to use maximum output, it would be good to get a cell with a continuous rating at or above the maximum current draw. Both to achieve the real max output and for safety sake. I doubt that anything will blow up or catch fire, but with good cells of the correct CDR are relatively inexpensive, why chance it?

I just found this:
image
From a thread here. Makes sense to me.

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Alright! Thank you all for the insights, they were very valuable!! I asked this because I have two low-drain cells at home and wanted to repurpose them in this S6 that I plan to buy. In my country, it’s a bit tricky to find good cells, but I will order the S6 with a Vapcell M11 so that I can make the most of my flashlight and avoid accidents with lithium batteries. Thnks again!

I use Vapcell N40 in all my 18650 flashlights including S6 (5A buck). They all are buck/boost and N40 is rated at 10A which is plenty. And I get maximum capacity of 4000mAh.