We have an LED bulb maybe 6 months old, tops. It has already died. The bulb gets a lot of “brief, on” and “long, off” cycles. I note this is highly likely an older, LED bulb sitting in my garage. It could be that LEDs don’t like such a cycle. Or, more likely, perhaps there was an older generation of low-end*, Walmart LEDs that did not live up to their long life, as claimed. I do recall a period (maybe pre-pandemic) when these low-end*, Walmart LEDs did not last no matter where I used them. I was very disappointed, but then maybe the technology improved because i noticed the same category of Walmart LEDs started lasting a few years. Still, they did not last as long as claimed, but good enough for me.
a) Did conventional LEDs (ie, in place of conventional, incandescent bulbs) go through some technological improvements?
b) This particular LED bulb (with “brief on” and “long off” cycles) developed a glow when it burned out AND the light switch off for at least 24 hours. Where is it getting the energy from? I WAG we have boosted the Wi-Fi throughout the house, and possibly the Wi-Fi signal excites atoms in the burned out bulb? (FYI: The Wi-Fi has been boosted for some time, and this has not been observed in other LEDs in various places around the house.) Any factual answer?
*low-end because Walmart offers more expensive LED bulbs claiming to last even longer.
I don’t think it’s so much about generations. Rather, some are just cheap and shoddy, and some are higher quality. The higher quality ones are probably more common now than they used to be, but there have always been good ones, and will always be bad ones.
Sounds to me like the light fixture is improperly wired and is switching neutral instead of switching hot. With hot constantly connected to the bulb, you can get a faint glow with LED lights even when off because some weak capacitive coupling to GND is enough to (very weakly) turn on the LED bulb.
I suspect this might also cause the longevity issues but I’m not sure about that part.
I think this can only be described as “bunk.” And, that’s being charitable.
More likely is that the lamp was made with cheap electrolytic caps. Those, plus high temperatures equal short life.
No, @Folly is essentially correct. The only way in which @Folly’s answer is incorrect is in assuming that it is strictly necessary for the light to have a switched neutral. Even capacitive coupling between hot and neutral lines alongside one another in other parts of the house (not the switched line to the light) can (rarely) produce a sufficient tiny AC voltage in the neutral to cause LED’s to glow, with some types of driver. High-quality bulbs include a high value (500k-ish) resistor across the LED’s to ensure the LEDs turn off fully, in spite of this phenomenon.
Further, having pulled apart many failed LED bulbs (and being a Youtube technical video tragic (BigClive rulez!)) I can tell you that while some of them fail due to failed electrolytic caps, there are numerous causes and electrolytic failure is not the most common IME. Other common problems are low manufacturing standards (dry solder joints), overheating due to failure of heatsinking, and failure of the LED’s themselves. I would say failure of the LED’s themselves is the most common problem.
As to LED lifespan, heat is the key issue. An LED that is driven hard (more current) will produce more light but less light per watt, while also producing more heat with consequent reduction in lifespan. Correspondingly an LED that is relatively “under-driven” (less current) will produce less light but more light per watt, and less heat resulting in a longer lifespan.
This leads to an inherent moral hazard for LED bulb manufacturers - – a bulb that contains fewer LEDs that are driven harder will produce the same amount of light, but be cheaper to manufacture and require more frequent replacement.
A few years back there was a stir in the electronics community when people learned about the so-called “Dubai Lamp” by Phillips. Dubai apparently insisted that Phillips produce a bulb that had more but relatively under-driven LEDs than standard, to save energy and last longer. Phillips obliged but at least initially would not sell the bulbs outside of Dubai and probably tried to keep them somewhat secret. I understand that due to EU regulations, such bulbs either have now or shortly will become more widely available.
To come back to the OP directly I would say that your experience is not uncommon particularly with cheapo bulbs bought a few years back.
One of the interesting things about pulling apart (or watching others pull apart) numerous LED bulbs is the lack of current conformity in design. The designs are all over the place. My thinking is that we are at a relatively early stage of LED bulb development and I expect that in the next few years, designs will converge on one or two that are found to be reliable, and many of the quality issues will disappear.
The OP mentions the bulb “sitting in the garage”. It’s not clear that this means it sat in the garage before being installed somewhere else or was installed in the garage.
If it was the latter and the garage gets fairly cold in the winter then one explanation is the cheap driver circuit (and the electrolytic cap in particular) couldn’t deal with start-ups in the cold and eventually failed. (The LEDs themselves are unlikely to fail in cold. This leads to a lot of misinformation on the Net as “experts” point out that the LEDs don’t fail in the cold implying LED bulbs are great in the cold.)
Some of my neighbors have outdoor LED porchlights and such that they leave on a lot. Several of them flicker horribly in the cold.
If I put LED bulbs in the chandelier in my dining room, they glow slightly even when it’s turned off. I called an electrician, who told me that the problem is that another light on the same overall circuit is on a three-way switch; apparently something about there being a three-way switch in the circuit, even though the switch that controls the chandelier is a standard on/off switch, causes a tiny bit of current to leak through. That bit of current isn’t enough to light an incandescent bulb, but it’s just about enough to cause that glow in the center of an LED bulb.
The electrician assured me that there’s no hazard involved; but it bothered me to have that light glowing when turned off, so I took the LED’s out of that particular fixture and put incandescents back in. The incandescents are now off the market so when my stock runs out (I do have some in reserve) I’ll have to decide whether to put up with the Always Slightly On fixture, or to pay an electrician to re-wire things (old wiring buried in the ceiling, not a simple job), or maybe to buy a different fixture.
So I guess all that longwindedness is a prelude to asking – do you have any three-way switches on that circuit? Maybe that light, or something else, is controllable both from the door into the house and the one out of the garage?
That’s an interesting thought. I guess a three-way switch is really two switches that can control the same lamp, as you say about a dining room chandelier? This bulb is in a hallway wwhere two swicthes can control it, so you may have a valid point. However, it only happens once th bulb burns out and the switches are in the “off” position. Still, your story may give me some insight.
i just wanted to thank everyone for sharing their great thoughts ans experiences. I should have explained the bulbs are strored in an unconditioned garage. These are not in use at this time, but some of these could wind up being installed in the garage sometime down the road. It’s the luck of the draw, really.
Maybe that’s the only time you notice it? You may not often be in your garage after dark with the lights off. I sometimes pass through the dining room after dark when lights are on in an adjoining room, but not in that one.
The chandelier’s not on a three way; what’s on a three-way is the light for the stairs and upstairs hall. However, both of those are on the same circuit. – though it occurs to me that so are some other ceiling lights which have LED’s in them and don’t do that. So maybe it happens with some LED bulbs but not others.
Interesting. Looking it up, it looks like 3-way switches just tend to run two wires parallel to each other from one switch to the other This results in the capacitive coupling mentioned earlier that can be a source of enough current leakage to turn an LED bulb on dimly.
We have about three light fixtures in our house and one in my wife’s Toyota 4Runner – all converted to LED bulbs.
Each chewed up 2-3 bulbs annoyingly quickly before we got to the final bulb (that – years since – haven’t needed changing).
I think these are cheap to make, even cheaper if your tolerance for poor QC is high, and sometimes you have to kiss a few frogs to get to the prince.
The margins are there even with a high failure rate. The inconvenience to the end-user isn’t really a line item on the seller’s spreadsheet.
It’s worth clarifying that – in all these cases – nothing else but the bulb changed. Two suppliers tried to tell us we had house- and car-wide electrical problems that were causing the LED failures.
I just watched this video, and I think he provides a convincing argument on why some LED bulbs fail prematurely. He said cheaper LED bulbs will fail when the bulb operates at a high ambient temperature, and this will occur when the bulb is installed in an enclosed fixture (which are very common in homes). And if you read the fine print on the packaging it will say, “Not for use in recesses cans or totally enclosed fixtures.” To get around this you can purchase LED bulbs that are supposedly designed for use in enclosed fixtures, albeit for a higher price, of course.
For what it’s worth, I can order LED bulbs that are rated for enclosed fixtures from my power company for about the same price as the cheap ones from big box stores. I’m pretty sure the power company is subsidizing the cost of the higher quality bulbs. But I imagine a lot of people just note the price and ask “Why would I order these from the power company when I can just pick some up at Target for the same price?” That was what I thought until I noticed the ones from the power company actually state “Can be used in totally enclosed fixtures” whereas the ones from Target all have that disclaimer you mention.
In addition to being operated at too high of a temperature, I’m guessing some LED bulbs are just… junk, and the stated lifetime is something the manufacturer made up.
There’s probably also a bathtub curve to the failures. Any manufacturing process sometimes produces defective products, and defective products usually fail pretty quickly. Ideally, the fail before they even leave the factory, and get filtered out in quality control tests, but that doesn’t alway happen, and so you still get some products failing for consumers shortly after they’re bought. Any reputable manufacturer will replace the product if that happens, though for something cheap like a light bulb, it might not be worth the consumer’s time to bother with that. So you get a decent number of failures right away, but once the defective ones fail, all the ones left are good products, that will last a very long time and then fail only gradually.
In other words, most product failures happen quickly, or after a long time. Graph this, and the shape of the graph looks sort of like a bathtub.
As an aside, one consequence of this is that it’s almost never worthwhile to buy an extended warrantee. A regular warrantee should cover almost all of the quick failures of defective products, and an extended warrantee won’t stretch the covered period long enough to cover the ones that wear out from age. So you’ll almost never use an extended warrantee, so it’s pure profit for the seller.
