LEDs have a general life expectancy of 50 000 hrs. If you use your lights for 10 hours a day, this should be 13.7 yrs. If this is correct, then LED’s are definitely an investment, even the top of the range bulb would work out to cost £2.55 per year. Add that to the saving you would make on energy and you’ve got a very cost effective bulb!
However, there are times when, even high quality, LED products can last as little as a year. The problem with these can be attributed to a large number of things, here are a few main causes:
Designing a heatsink is a fine science. Some heatsinks do not have the correct amount of surface area, some do not take into consideration about the gaps between fins to enable air flow. Some have horizontal fins, when they are positioned vertically. The main design fault with the latter, being that heat rises. Rather than dispersing the heat away from the bulb, the heat coming from the lower fins heat the upper fins even more.
Most, standard, electronic capacitors are made from a plastic. These have an average life time of around 1 year, if used regularly. Capacitors are part of the circuit in every LED driver. Now a number of companies are making their capacitors from ceramics, giving them a much longer life expectancy.
LEDs are usually designed to work in our country, and in our climate. If they are used in a hot country, or enclosed area, the heat around them can easily surpass the heat they were designed to withstand, shortening their life time.
To get LEDs to their full potential, these factors, among other considerations, must be taken into account.
Thanks for the sensible article. As an EE, this is the only information, after much searching, with sound technical reasoning. My dilemma is the overall cost and environmental impact of LED bulbs. Over the past two years at my home, I have replaced 14 LED light bulbs (Feit Electric from Costco) that have lasted anywhere from three weeks (~200 hours) to two years (~4500 hours). This causes me to question claims of 50,000 hours or more of bulb life (of course this is based on the LED chip itself, not the finished product). As heat in general is an enemy of electronics, I do not see any venting. After much effort to cut off the plastic globe, I did not see any heat sink. I also inadvertently validated the impact safety claim. Certainly some heat must be generated to reduce the 120V/60 Hz power source to a few DC volts. Having used CFLs (13W or 60W equivalent) for over a decade and seeing bulb life spans of 4-7 years, I must re-evaluated the economic and environmental benefits of LED bulbs (9.5W or 60W equivalent). High-end, much more expensive bulbs are available rated 100,000 hours for commercial use. This webpage (http://wavelengthlighting.com/blog/2013/12/2/lights-out-the-practical-life-expectancy-of-leds) provides a professional opinion that varies from 2-3 years to 3.5-4 years. BTW, professionally over the past 30 years I have rarely seen an LED replaced in electronics equipment and computer servers that is on 24/7 for a decade or more (of course these are powered directly from a DC power source). Maybe it’s time write Consumer Reports.
Thanks Alan M The quality of led replacement bulbs varies incredibly – I have cut bulbs open that have no heatsinking and use a single-capacitor impedance dropper instead of a dc-dc converter. Lifetime also strongly depends on the housing in which they are installed – some light fittings allow almost no airflow. The better led-based replacement light bulbs actually back-off their output above a certain temperature to allow them to ‘work’ (at less than stated output) under such duress. For my house, I only fit the better quality type with real heatsinking – and i have yet to have one of these fail. Roll-on mass-availability of integrated led luminairs for homes.
in regards to ge led light bulbs, good luck returning the ones that fail to the point of purchase(the store). They show you an address of which YOU have to send their defective product(at your expense). Then after paying the shipping six bucks and some change, you play a waiting game. Then after four FULL weeks,,,VIOLA, a ‘dear dan’ letter arrives, informing you that ”it appears from our engineer’s inspection of your bulb, that you installed it incorrectly”. REALLY,,,since when is turning a bulb clockwise in a standard light socket, installing it wrong? Note, I will be removing any/all things ge related in our home as soon as I possibly can.
Dan, with my professional experience for over 15 years with LED design I must say that GE LED are not only the WORST, but also the DANGEROUS ones on the market! For 15 years ONLY GE LED have burst in FIRE, endangering everything around them! Stay away from ANY GE consumer electronics as they fave the worst reliability check possible!
Interior hallways currently have 2 U bent 32w T8s per fixture. Lighting is on 24/7 and have been in place 5 years. Retrofit considered is plug and play LEDs. Questions: ballasts – based on past usage (40,000 + hours) would new ballasts need to be installed? If not, than when? LED linear lamps – will 24/7 cut down life span?
Hi John. Turning them on and off will make very little difference to life expectancy, if at all. What will make a big difference is poor ventilation as the components inside, particularly the electrolytic capacitor, fail more quickly when kept hot.
Is LED bulb life reduced by being turned on & off often (i.e., is it better to leave them on for an entire evening) ?
I agree with Dan. I would use multiple aa, or aaa batteries (cells). Please observe the wiring configuration. Series wiring should be use to obtain the correct voltage for your LED application. Additional batteries / cells can be connected in parallel to increase current capacity.
Also make sure to NOT connect your LED directly to the power supply. You want to connect the LED in parallel with a resistor (about 330 ohms).
A proper heat sinks should also be used with your LED to dissipate heat effectively for long periods of use.
If you have any questions please write back.
P.S. Funny about the 600aH battery lifting. I work with 225aH batteries and they are about 160lbs per.
You wouldn’t use a 9V battery, unless you really need 9V in a compact form. Instead you’d use multiple AA or AAA batteries. With AA you can easily supply ten or more times as much energy as a 9V.
@James Actually James, Atlas is correct on his life-span of a 9V battery. His only mistake was writing 600Ah and not 600mAh. The average 9V battery has about 550 mAh, thats milliamp hours, or just above one half of a single amp hour. Thus, with an LED running at 20 milliamps (to stay consistant with Atlas’ example), the average 9V battery should be able to power it consistantly for about 27-30 hours.
I wouldnt like to have to lift a 600Ah battery? It would be huge 🙂
@Atlas Actually you are wrong. the average 3mm type white led has a max safe current draw of about 20 milliamps. this would mean that a 9v battery with a 600ah capacity would let a single led last for: 600/0.02 = 30,000 hrs of use. if you used it for 13 hrs a night it would last for ~6.3 years. i rest my case.
I come from the future bringing you news.
Battery + LED = crap lifespan. In my opinion.
A 9V battery is average 600ah and with a typical LED having a draw of 20amp it would only last about 30 hours.
how long is the usual life span of a good battery for a led light what is the best battery out there that i can us that is small a durable but that will last quite some time and if there is such thing how many hours or years can this battery last if i use it for 13 hrs a night
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