About LED lifespan

Modern LED Chip with no bond wire.

One of the questions asked most often by our clients is “What is the life expectancy of LED lights?”.

The lifetime for high pressure sodium or metal halide bulbs is typically 15000-25000 hours, that is more than half will have stopped working in this time. LED lifespan refers to the time when the LED light output reaches 50% of the rated luminous output, not reaches zero. Often there will not be a critical failure of an LED light, only a reduction in brightness.

Some companies claim that their LED light has a life of 50000 hours or 100000 hours, actually, it is very hard to give an accurate life for a LED light. While some companies may do some accelerated life testing, most make an estimate based on data sheets from the LED chip manufacturer and some assumptions of how the LED chips will behave in the final luminaire. Often it is not the LED chips themselves that fail but poorly designed driver circuitry populated with cheap components that stop working. Some manufacturers also pay little attention thermal management in the lamp leading to lamp failures much, much sooner than the lifespan quoted by the LED chip manufacturer.

Dialight carefully designs its luminaires to ensure that the driver circuitry and components are suitably specified and thermal management is more than adequate for the application. Dialight then uses accelerated testing of the whole luminaire to accurately establish the average lamp life of at least 60000 hours. This is why Dialight is able to offer a full 5 year manufacturer warranty backed by a £100m+ UK PLC.

Then we have to consider lumen decay and maintenance. A traditional high pressure sodium or metal halide bulb reduces in brightness by up to 44% to the end of its life when it breaks. Dialight uses Cree XLamp XP-G LED chips to achieve a reliable 80%+ lumen maintenance after 60,000 hours. In the same time you would have had to replace the bulb in a traditional lamp 3-4 times.