DC LED lamps

Muse

Lifer
Jul 11, 2001
33,137
5,056
126
Over the last several months I've bought a few kinds of these. I just received a couple of these, which I really like:

2 Pack Miady Clip on Lamp, Battery Powered Reading Lamp, Clip on Light for Bed Clip on Battery Light with 3 Brightness Level, USB Rechargeable


Three brightness levels, it's pretty cool light ("5000k"), each lamp includes a 1000mah 18650 battery (they claim it's 1200mah, but I measured it at 1000mah in my Xtar charger). The battery is easily removable and I replaced each with a 2600mah protected cell.

I'm wondering how long the LEDs will last. There are 18 LEDs in the lamp head. I'm running one of these off the charging cable, having removed the battery. If I leave it on low as a night light (~15% the juice of high), will it likely last over 50,000 hours (I am guessing that on low or medium the LEDs will last longer than on high)?

I measured the watt usage when run off USB using my Kasa KP115 energy measuring smart plug:

High: 2.6w to 3.6w (depending on the USB charger, my SlimQ 65w GAN charger does better than the others)

Medium: 1.4w to 1.6w

Low: .45w to .6w
 
Last edited:

sdifox

No Lifer
Sep 30, 2005
87,645
10,708
126
The diodes will probably die before the actual LED does. I doubt you got high end lamp so don't expect long life.
 
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Red Squirrel

No Lifer
May 24, 2003
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Typically it's the driver circuit that dies before the actual LEDs, though in some cases they also overdrive the LEDs to get more brightness, which then may kill the LEDs. Lookup Dubai lamps. Those are illegal here but basically in Dubai they are more strict about products made to fail and forced the manufacturers to make bulbs that last longer. They basically just add extra LEDs so that they are not overdriven.

I would not expect anything from Amazon to last very long unless it's from a legit supplier that also happens to sell on Amazon too.

One thing I want myself is a LED flashlight that takes 18650 cells and has a simple on/off button, no stupid flash modes. Seems impossible to find though. Even the hardware store flashlights have that crap now. I need to make my own at some point.
 
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Muse

Lifer
Jul 11, 2001
33,137
5,056
126
Typically it's the driver circuit that dies before the actual LEDs, though in some cases they also overdrive the LEDs to get more brightness, which then may kill the LEDs. Lookup Dubai lamps. Those are illegal here but basically in Dubai they are more strict about products made to fail and forced the manufacturers to make bulbs that last longer. They basically just add extra LEDs so that they are not overdriven.

I would not expect anything from Amazon to last very long unless it's from a legit supplier that also happens to sell on Amazon too.

One thing I want myself is a LED flashlight that takes 18650 cells and has a simple on/off button, no stupid flash modes. Seems impossible to find though. Even the hardware store flashlights have that crap now. I need to make my own at some point.
I bought a couple 18650 flashlights that are pretty simple, but they do have a strobe mode if you hit it. But I think you might not be unhappy with it. Wurkkos FC11. Cheapest direct from Wurkkos.

I'm thinking probably these lamps last longer if used on medium than max. Well, I'm pleased with them so far, have 4. Seem well built and I love the fact that I can swap out the batteries in seconds. The 5000k color is kind of blue compared to what I'd prefer but it's not bad. There's 18 LEDs in the head. I think I'm going to use all but one with battery removed, using a USB cable to drive them, keep the 4th for utility usage using a battery.
 
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