LED Lifetime test
Posted: Thu Mar 11, 2021 10:56 am
I have had several LED lamps myself which have lasted much less than the rated lifetime. I have had Philips and Wilko LED lamps where some have lasted much less than their rated lifetime.
https://www.edn.com/how-long-do-leds-really-last/
https://www.edn.com/how-long-do-leds-really-last/
Most important, how do we know these claims are accurate – and then I was off on a research mission. A little more than a year ago, the Daily Mail ran an article claiming that 25% of the expensive long-life bulbs came up short on the claims—with some even falling below the European Union’s legal minimum life of 6,000 hours. These were bulbs that claimed between 15,000 and 25,000 hours of use.
The article discussed tests on five samples of 46 types of bulbs by European partners and consumer watchdogs. The test involved turning bulbs on for 165 minutes and off for 15 minutes until failure. The results of the test:
Five types stopped working before 6,000 hours
Five with claims of at least 25,000 hours stopped before 10,000 hours
66 out of 230 samples failed before 10,000 hours even though claims were for at least 15,000 hours of use
Not a fan of the Daily Mail ? What might you believe? The U.S. Department of Energy’s website discusses tests for a variety of bulb types. For instance, it states that, “CFLs are tested according to LM-65, published by the Illuminating Engineering Society of North America (IESNA). A statistically valid sample of lamps is tested at an ambient temperature of 25° C using an operating cycle of 3 hours on and 20 minutes off. The point at which half the lamps in the sample have failed is the rated average life for that lamp. For 10,000 hour lamps, this process takes about 15 months.”
In that vein, how long do you think a bulb claiming 50,000 hours would need to be tested? Try 5.7 years. What it comes down to is that there seem to be no real sure-fire ways to test the long-term performance/viability of the LED.