How Long do LEDs in High Lumen Flashlights Last? (Explained)

Quality Flashlights

A quality flashlight is a joy to own these days. The batteries are small with high capacities, you just plug them into a USB lead to top the cell and away you go. 

They’re now small enough to fit inside the top of a shirt pocket and carry around all day without even noticing it’s there.

I occasionally get asked at dinner parties when I produce my selection of pocket EDC flashlights from my tux, “Hey how long does that thing last”. It’s a question that’s been burning into my psyche since I picked up my first real LED flashlight at Bob’s Store way back in the day.

LED Emitter Manufacturers

To understand the lifetime of an LED light source it’s worth taking a moment to look at who manufactures these “wonders of light” as you’ll see in a moment why it’s helpful in answering that age old question.

Way back in the day, 1987 to be precise there was a little company called Cree which was founded at the State University in North Carolina.

Cree LED Components

Jump forward to 2007 and Cree [1] are now an established player in the LED market place. It’s also the year where they launch the first commercially viable LED. The modern LED flashlight is almost upon us.

Today Cree is the biggest manufacturer of LED emitters in the world. There are others, take a look at the list here [2]. However, Cree dominates the LED market and chances are your flashlight is going to have a Cree LED emitter at its head.

Reported LED Lifetimes

I’m going to use Cree now as my base example for the figures that I’m going to highlight. You’ll now know the reason as to why I’m using their laboratory testing as my basis.

The Cree Components PDF Testing results is here [3] for anyone who would like to take a look.

Theoretical LED Lifetime

There are a whole load of factors that are going to affect the lifetime of an LED in the real world as the real world is different to a laboratory. 

How your flashlight is exposed to the environment is going to have a degree of influence on the lifetime, although this would be nominal.

If you take a look at the figures recorded in the lab, the lifetime varies from according to the drive current. 

Emitter Example

Let’s look at the XP-G2 emitter for example.

• At 1050 mA drive current the lifetime is 57,500 hours
• At 2000 mA drive current the lifetime is 36,300 hours

Both of these tests were carried out under the same conditions.

In the real world 2000 mA current is going to be driving the high mode on most flashlights.

If you ran the flashlight for 8 hours a day for 365 days on high lumen mode output, the total amount of hours would be 2920 hours for one year.

In that case it would take 12.5 years for the LED emitter to drop in output. 

Summary

As you can see, the lifetime of an LED emitter is huge. The power switch or user interface as it is known is most probably going to fail long before the LED.

Most flashlights are drop tested to 1.5 metres and have an IPX7 rating. This means they are durable and able to be submersed under water, plus take a drop from a reasonable height.

I personally wouldn’t worry too much about the LED emitter failing on my own flashlights. If there is a manufacturer’s fault which isn’t out of the question it will usually show up during the warranty of the flashlight.

I hope you’ve found this article useful and somewhat entertaining. Let me know of your experiences of LED failures on one of your high lumen output flashlights in the comments section below.

Stay safe out there and let there be light!