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  1. #1
    Join Date
    Jul 2012
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    9

    Default LED flashlight problems - flickering and quitting

    Over the past few years I've bought a dozen or so of these things. As of now, I have one (1) that still works(sorta).

    The batteries aren't the problem and I don't think it's the bulbs. In every situation, the flashlight turns on and works correctly for a time that seems to vary (long enough to lose the receipt). Then in the middle of a use - it quits! Banging it (gently @ first anyway) with my hand restores the light, then the process repeats.

    So far, my experience is with the "aaa" battery types - usually 3 of them in a plastic holder which I suspect may be the culprit (too many contacts to maintain). Also, my experience has been limited to the lower price scales. I admit to being a miser but also have become disillusioned with the entire product line.

    I see they now offer LED flashlights that use "C" or even "D" cells with an in-line configuration. Has anyone out there have a good experience with these types?

  2. #2
    Join Date
    May 2008
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    Pacific Northwet
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    1,642

    Default Re: LED flashlight problems - flickering and quitting

    You'll find the problem in pretty much any flashlight -- the contacts corrode. In many of the aluminum flashlights with a screw-off cap on the bottom end, the connection between the cap and the body is the most likely culprit. Cleaning the mating surfaces between the cap and body (not necessarily the threads, but where the shoulder on the cap meets the butt of the flashlight body) fixes the issue.

    It tends to be more of a problem with LED flashlights because the electronics require some minimum voltage to maintain service. As corrosion increases, so does electrical resistance. With increased resistance you see a voltage drop. Add that voltage drop to the voltage drop of weak batteries and at some point it's not high enough to sustain the LED. Where an LED just quits, an incandescent flashlight gets dimmer.

    I've heard good reviews of Streamlight (very expensive) and LED Lenser (sort of expensive) flashlights. MagLite is OK, but very prone to the cap corrosion issue.

    If it has more than one LED, don't even bother buying it. That's the sign of a manufacturer that's too cheap to use decent parts.
    Last edited by Fencepost; 11-25-2013 at 01:47 PM.
    The "Senior Member" designation under my name doesn't mean I know a lot, it just means I talk a lot.I've been a DIYer since I was 12 (thanks, Dad!). I have read several books on various home improvement topics. I do not have any current code books I can refer to. I was an apprentice plumber for two years.

  3. #3
    Join Date
    Jun 2007
    Location
    Fayette County, Ohio
    Posts
    5,821

    Default Re: LED flashlight problems - flickering and quitting

    The problem with those small 3 AAA battery type flashlights is the cheap springs used to make them. When you tap them they make contact but if you turn the light over it looses contact. It has been my experience they are hardly worth the low price you pay for them.

    Jack
    Be sure you live your life, because you are a long time dead.-Scottish Proverb

  4. #4
    Join Date
    Jul 2010
    Location
    SoCal
    Posts
    6,692

    Default Re: LED flashlight problems - flickering and quitting

    If you paid $1 at the Dollar store or got it for free (from Harbor freight), it's worthless.

    If you need a flashlight for emergency or nightly use, then invest in a good quality flashlight.

    But even the expensive lights won't last. Manufacturers know how to make you come again and buy new.

  5. #5
    Join Date
    Aug 2007
    Location
    Maryland
    Posts
    1,667

    Lightbulb Re: LED flashlight problems - flickering and quitting

    Try tightening the inside of the head from the inside. Usually I see a ring that kind of holds things tight. Unless you have a special wrench, some other tool like a screwdriver or needle nose pliers partially open to grab the indentations and tighten the ring. Sometimes it helps, sometimes it doesn't. Sometimes the Chinese junk works for a while, sometimes you get what you pay for. I've never had any issues with quality/ expensive LED lights.

  6. #6
    Join Date
    Jan 2008
    Posts
    2,188

    Default Re: LED flashlight problems - flickering and quitting

    Fencepost is spot-on

    You don't get what you don't pay for in a flashlight. Even then many are not well-designed so will not last as you want them to. I have one "Streamlight"- a "Nano" model, which is the tiny key-ring model. It has problems with the switching but it is also the first one of this type I've ever had which lasted over a year of my abuse and still worked. All the others either fell apart or the switching mechanism became unreliable. I would have a new favorite brand with them save for the cost. My flashlights get abused and lost too often for me to spend huge money on most of them. My usual 'big work flashlights' are cheap 6V box-types; good light, decent economy, and worth the cost of the one Duracell battery life they usually last me before I lose or break the darn thing. My real emergency flashlights are all "Mag-lites" where it matters because they are as durable a flashlight as I know of, plus they come with a replacement bulb just in case you ever need it.

    What I've found to work with the aluminum-body flashlights is to clean all the screw-thread areas with a brass wire brush (steel will induce near-instant oxidation), then to apply a thin film of "No-Lox" or other electrical connector grease. Applying more than a very thin film will cause the grease to act as an insulator- I wipe tightly with a paper towel after application which leaves a minimal film that works to prevent oxidation but isn't creating an electrical insulator. Do this wherever two dissimilar metals meet too (especially on the lead contact at the bottom of the bulb) and they will always make good electrical contact.

    In general, I avoid flashlights with weak bodies (many plastics), sliding or crimped electrical contacts, 'switches' which just press a metal strip against another contact surface, and weak springs. When one goes out, if a gentle 'tap' doesn't set it to working, don't 'bang' it harder and expect to do no damage- you'll usually just cause the problem to get worse later on or break something. A better approach it to twist the threaded parts back and forth, which usually sets things right for now. Also feed your flashlights only the best batteries (I like Duracell) because you need them to work as well as possible, not to fail you when you really need them. When a cheap flashlight fails, just toss it- they're not worth trying to deal with. They have their place so long as you know what you've got- a cheap 'maybe' instead of a an 'always'. I've inadvertently stored Duracells ten years with no deterioration or leakage; not recommended but a solid statement of their quality. If it's vitally important, use only the good stuff. If it's something that will not get banged around, a lesser flashlight may do fine. Store all flashlights laying down, storing them on end will let the weight of the batteries bear on the battery spring or the bulb which will cause problems.

    Bulbs come in many varieties these days, with LED's gaining ground rapidly. Good light and essentially unbreakable, but as Fencepost noted when the batteries get low they die instantly with little or no dimming to warn you. Xenon bulbs are extremely bright and the better ones are pretty durable, but they can die when dropped. These give you a lot of light in a small package with less battery needed per Lumen but are costly. Conventional bulbs are cheap and have nothing else to recommend them now that we have better choices.

    I guess I'm something of a flashlight nut and collector- I even have a book on the subject and a few old and rare ones including a 1934 model which has a solid glass bulb that still works! I must have at least 20 flashlights scattered about, always one within reach wherever I'm at because you never know when you're going to want light.

    Phil

  7. #7
    Join Date
    Aug 2007
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    Maryland
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    1,667

    Default Re: LED flashlight problems - flickering and quitting

    I replaced the bulb in a mini-maglight with an LED I got at a local hardware store. What a difference in the light output and run time. I think the bulb cost as much as the maglight, but I just wanted to try it.

  8. #8
    Join Date
    Jul 2010
    Location
    SoCal
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    6,692

    Default Re: LED flashlight problems - flickering and quitting

    Quote Originally Posted by ed21 View Post
    I replaced the bulb in a mini-maglight with an LED I got at a local hardware store. What a difference in the light output and run time. I think the bulb cost as much as the maglight, but I just wanted to try it.
    I didn't know that they were interchangeable.

    I had a mag lite with 2-D batteries that stopped working due to battery leak. Without a receipt and out of warranty, mag lite replaced it free of charge, all I had to do was pack it and send it back to them ($5 in shipping). Unbelievable customer service.

    Mag lite is probably the only flashlight to get, if you need a serious flashlight for work or emergency. I still have all those toy flashlights as well. They're fun, as long as they work.

  9. #9
    Join Date
    Aug 2007
    Location
    Maryland
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    1,667

    Default Re: LED flashlight problems - flickering and quitting

    Quote Originally Posted by dj1 View Post
    I didn't know that they were interchangeable.
    It was more than just the bulb. It was the inside head with appropriate electronics. So far, so good with the LED.
    I haven't seen anything for the larger maglites, but I never really looked.

  10. #10
    Join Date
    Dec 2007
    Location
    Tennessee
    Posts
    1,768

    Default Re: LED flashlight problems - flickering and quitting

    I started using a two cell AA LED Maglight as an inspection flashlight at work when the first 1 watt bulbs came out (2005 I think). That flashlight is still working flawlessly. I have a 2D cell, two 3D cell Maglights and a 4D cell Maglight now and all of them have yet to have an issue.

    About a year ago, Costco had a two pack of 500 lumen tactical flashlights (3C cell) on sale for about $30. They are incredibly bright, just as bright as a 1 million candle power 12v Halogen light that I have and so far have been just as reliable as the Maglights. I don't think they have them anymore though.

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