How to fix this while I still have some hair left.

hbiss

hbiss

EC, New York NEC: 2017
Location
Little Falls, New York NEC: 2017
Occupation
EC
I've had a Nitecore E4K LED flashlight for some years. See the link below. Seems that everybody that has one of these things, whether Nitecore or Olight, has a flickering problem. It goes out or dims and you have to shake it or bang it to make it work again. It's not that these things are cheap, I originally complained to where I bought it and they said to return it to the manufacturer IN CHINA. Google the problem and I get what I already know, keep it charged and battery contacts clean otherwise return it.

So, knowing that the only thing it can be is the battery contacts, but what to do? I tried cleaning both ends of the battery and end cap with an abrasive and that did help for a while. My feeling is that this thing draws a large amount of current when it is on high (it gets HOT) (battery is capable of supplying 15A continuously) and any resistance causes a momentary voltage drop that triggers the dimmer control to switch to another level. That's why it refuses to go to high if the battery charge is below a certain point.

Any ideas?

https://www.zoro.com/nitecore-e4k-next-generation-21700-compact-edc-flashlight-e4k/i/G401984470/?gclid=e21df943b2b61f4e41d9911940f6b256&gclsrc=3p.ds&msclkid=e21df943b2b61f4e41d9911940f6b256&utm_source=bing&utm_medium=cpc&utm_campaign=text_rlsa_dsa_na_na_shopping feed priority skus&utm_term=Flashlights&utm_content=Top 100k Impression Products $dsa

-Hal
 
Check for a thermo-sistor or possibly a thermo-cap... on the board it will look like a orange motrin lookin thingy... it just opens the circuit when hot, pretty early in the circuit. Yoink it! Put in a fuse.

The battery may have the same thermo shut off.
 
Nah, you can't even get it apart. It does have thermal management though, keep it on high long enough and it will kick down or hold the light too close to something and it will kick down. No, this is an intermittent problem with the battery contacts, I'm sure of it.

-Hal
 
hbiss said:
flickering problem. It goes out or dims and you have to shake it or bang it to make it work again.
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Don't all flashlights do this, except hardwired rechargeable's, like headlamps, and phones.
Jraef said:
Battery contacts build up a coating of some sort.
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Yep, it doesn't take long for LED flashlights to flicker, which hardly pull any power.
 
ramsy said:
Yep, it doesn't take long for LED flashlights to flicker, which hardly pull any power.
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Not really. These suckers pull a lot of power. Read what I said about the battery being capable of supplying 15A continuously. That's a small flashlight and I carry it in my pocket and I have to make sure that I unscrew the end cap a turn or two to make sure it doesn't turn on in my pocket. I have no doubt that it would burn a hole in my pants- or me.

Jraef said:
Battery contacts build up a coating of some sort. I pull mine out and rub it back and forth on my jeans really hard, fixes it for about another month.
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Battery ends appear to be nickel plated. I have rubbed them on everything from copy paper to more aggressive abrasives. Usually it helps for a while. I can't tell if the contacts heat up and cause oxidation. Must be something that you could coat the battery ends with.

-Hal
 
I've never owned a high-end LED flashlight, but ALL of the ones I have owned seem to require "percussive maintenance" on a regular basis while in use. The handiest surface is usually my head.
 
Check the contacts when hot and naybe cold. Use a sharpie on the batt terms and check contact when its failing.

Hell, they might be thermo stripping! Other wise, its internal.

I could get it apart :)
 
hbiss said:
Any ideas?
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Throw it away and buy a Olight. I've have many of their EDC lights and have not had any issues with any of them.
Love the magnetic charger on the back and one push of the button shuts it down to prevent the hole in pocket.
 
hbiss said:
Not really. These suckers pull a lot of power. Read what I said about the battery being capable of supplying 15A continuously. .

-Hal
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15A continuously is marketing hype. Unless by continuously they mean seconds.

Are you performing their recommended periodic maintenance mentioned in the manual?
As pointed out it does not take much resistance at higher currents to cause a significant voltage drop in a 3.7V circuit.
 
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