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There's something off about LED bulbs

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Re: There's something off about LED bulbs

#541

Post by xxs »

formerly_proven wrote: post #24

There's a lot wrong with LEDs in general and retrofit (E27 bulbs) in particular. In no particular order - LED emitters driven hard for cost reasons, age and fail quickly - Power supplies driven hard for cost reasons, age and fail quickly - Poor CRI and SSRI - Flickering - Dim-to-warm is uncommon - Poorly designed power supplies that age and fail quickly - The same light quality is vastly more expensive to achieve wit…

The same topic about LEDs has so many entries on HN in the recent years. I have posted about it a lot. To add to the list

  - low power factor (usually 50%).
  - cheap passives, caps/coils
  - terrible heat dissipation, e27/e14 are no good target, but see overdriven again
  - close to no input protection (see power supplies, again), so motors totally wreck them with their induction kickback
OTOH, constant (not over)driven LEDs with dedicated power supplies (pref. isolated, so safer), with decent area, aluminum PCBs can last long.

A cheap advice if you have to buy a retrofit LED bulb, buy the heaviest one, i.e. get a scale with (at least) gram precision and weight them. More mass - better heat dissipation, better passives.

Re: There's something off about LED bulbs

#542

Post by tomatocracy »

iso1631 wrote: post #159
DougN7 wrote: post #135

Earlier quoted context omitted.

This is just an anecdote, but I’ve had multiple “10 year” LED bulbs fail after just a year or two. I suspect much of the claims for these bulbs are theoretical as they just don’t hold up, probably for reasons the grandparent poster is pointing out.

On the other hand I lived in my last house for 5 years and didn't replace a single bulb.

When I moved into my current place 5 years ago a lot of the lighting was 12V MR16 halogen bulbs. I replaced most of them with high CRI Philips Master LEDspots (specifically marketed as having a longer lifetime aimed at commercial installations but they weren't significantly more expensive vs "consumer" versions at the time if you were looking for high CRI anyway) and kept the transformers in place. I've had one fail out of probably 50 or so bulbs in that time, which feels about par for the course to me.

Re: There's something off about LED bulbs

#543

Post by xxs »

blisterpeanuts wrote: post #280
JohnFen wrote: post #198

Earlier quoted context omitted.

Almost all LED bulb failures are because the power supply died due to overheating, not the LEDs themselves. I harvest the LEDs out of dead bulbs to use in hobby projects. With Edison-style bulbs, anyway, the orientation they're mounted in makes a huge amount of difference. They're last a lot longer if they're oriented upright (base down) than in any other orientation because it reduces the heat buildup in the power s…

>> I harvest the LEDs out of dead bulbs to use in hobby projects. This is a great idea and I would love it if you would post a Youtube how-to video. It might encourage a bunch of hobbyists to do something useful with those dead bulbs. I've had a number of LED's fail after only a year or two, in fact more quickly than the average incandescent bulb. Seems like it defeats the whole purpose of "upgrading" and in fact may…

Actually it's a terrible idea - those LEDs have been overdriven to hell and back, their luminosity and overall lifetime decreased.

LEDs are super cheap. I bought few hundred pre-covid for $3.

Re: There's something off about LED bulbs

#544

Post by IshKebab »

wankle wrote: post #313

https://www.stouchlighting.com/blog/light-comparison-led-lig... . "New LEDs can last 50,000 to 100,000 hours or more. The typical lifespan for an incandescent bulb, by comparison, is 1-5% as long at best (roughly 1,200 hours)." I've never seen more than 15000 hours from an LED bulb at best. https://en.wikipedia.org/wiki/Incandescent_light_bulb "The chart below lists values of luminous efficacy and efficiency for some…

You're buying terrible bulbs if you've never seen one last 15k hours. Just buy some reputable branded bulbs (e.g. Phillips) rather than no-name cheapo crap from Amazon.

I can't really remember how long incandescent bulbs lasted, given that it's been over a decade since anyone in the EU used them... But good LED bulbs last plenty long enough.

Re: There's something off about LED bulbs

#545

Post by Tade0 »

fy20 wrote: post #464
Agentlien wrote: post #246

Earlier quoted context omitted.

I read a lot of the other comments here before yours and they all seemed to describe a reality very different from my own experience. Then I saw yours and it suddenly makes sense. I am also in the Europe, most other commenters seem to be from the US. Here I find it is very easy to find good LED bulbs with the strength and color profile of my choice and I have used LED in all rooms of my house for the last 10+ years w…

I'm not sure if this is the norm in Europe, the only chain store I know that sells high CRI (>90) bulbs is IKEA. If I go to my local home store or supermarket, they are all junk Chinese bulbs that I doubt are really even 80 CRI. CRI isn't even something you can filter by on their online catalogues. At least the new EU energy labeling let's you see what the specs are.

Cheap bulbs do a lot of "CRI hacking":

https://www.waveformlighting.com/tech/what-is-cri-r9-and-why...

It's easy to make a bulb that scores higher than 80 - still, they usually have poor R9 (red reference light source) scores, which is noticeable.

Re: There's something off about LED bulbs

#546

Post by mturmon »

tomatotomato37 wrote: post #150

I hate how many of these things aren't limits of the technology but rather the result of cost optimization and general apathy towards the customer. We know how to mass-produce quality LEDs to the point entire TVs are made of the things. We know how to mass-produce rectifiers pretty much ever since diodes existed. We know how to cool mass-produced objects in compact spaces. But because we apparently can't have nice th…

I fully agree, and would add that imposition of these artificial limits seems to be a fundamental side-effect of capitalism.

"Good old-fashioned" incandescents were also subject to a multi-decade scam to limit their lifetime: https://en.wikipedia.org/wiki/Phoebus_cartel

It's manifesting slightly differently this time around, but it's the same principle.

Re: There's something off about LED bulbs

#547

Post by 01100011 »

wankle wrote: post #313

https://www.stouchlighting.com/blog/light-comparison-led-lig... . "New LEDs can last 50,000 to 100,000 hours or more. The typical lifespan for an incandescent bulb, by comparison, is 1-5% as long at best (roughly 1,200 hours)." I've never seen more than 15000 hours from an LED bulb at best. https://en.wikipedia.org/wiki/Incandescent_light_bulb "The chart below lists values of luminous efficacy and efficiency for some…

For me, LED bulbs have a failure curve like any other electronic device: high level initially and quickly levelling off to zero. I've probably had... 10% of my bulbs purchased in the last decade or so go back to the store because they've either failed or started flickering. Outside of that, I have zero failures after having the bulb for a month or two. I have a box of bulbs and some of them are bulbs I bought years ago and pulled out of my house when I moved, and I've used them at various apartments since. Still going great.

Edit: one other thing, I'm also sensitive to the cooling needs of LEDs, so maybe that helps. At my last apartment, I had the 'ceiling boob' style built-in fixtures which didn't allow proper airflow for the LED. I built a little spacer and got a longer mounting rod to allow a 1/8" gap around the bottom, central hole and the top edge of the glass. That kept the LEDs cool and wasn't noticeable.

Re: There's something off about LED bulbs

#548

Post by blyry »

Lightbulbs are infuriating now-a-days. I want poe-driven wired IoT bulbs (and downlights, and I suppose zigbee/zwave where poe can't be added in) that dim and color change on the white spectrum (no rgb silliness I will never need to make my lightbulbs green or purple or whatever), with no flicker and high CRI / full spectrum.

And a black box controller that matches output to exterior conditions automatically. No app, just a black box with a wired light sensor.

You can rip my halogen reading lamps cold dead hands.

Re: There's something off about LED bulbs

#549

Post by wiradikusuma »

I don't finish reading the article because it seems the author is very unlucky with LEDs, but LEDs really that bad?

You know that thing where you didn't notice anything wrong until someone mention it and suddenly you notice it too? It doesn't happen to me after reading the article. What should I pay attention to my LED bulbs so I can be on the same page with the author?

Re: There's something off about LED bulbs

#550

Post by xxs »

JohnFen wrote: post #198
DougN7 wrote: post #135

Earlier quoted context omitted.

This is just an anecdote, but I’ve had multiple “10 year” LED bulbs fail after just a year or two. I suspect much of the claims for these bulbs are theoretical as they just don’t hold up, probably for reasons the grandparent poster is pointing out.

Almost all LED bulb failures are because the power supply died due to overheating, not the LEDs themselves. I harvest the LEDs out of dead bulbs to use in hobby projects. With Edison-style bulbs, anyway, the orientation they're mounted in makes a huge amount of difference. They're last a lot longer if they're oriented upright (base down) than in any other orientation because it reduces the heat buildup in the power s…

>Almost all LED bulb failures are because the power supply died due to overheating, not the LEDs themselves.

I have the exact opposite experience, virtually every single light bulb I have torn down - one LED (all in series) has a black dot, if I shorten it - it will 'work' again. The bulbs I have seen tend to drive the LEDs so hard that some of the latter fail, power supplies might have huge ripple but generally don't fail catastrophically.

Edit: now thinking, it can be a US thing, with the voltage being ~120. Lower AC voltages means worse efficiency for the power supply (and all of them tend to be universal, unless totally cheapen out on the primary capacitor [250V] for the US market). Generally speaking low AC voltages have mostly disadvantages.

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