So if we define 50% as the end-of-useful-life point, and if a flashlight is used for 1 hour a week (and even that might be a lot for a typical homeowner, who would use the flashlight sporadically, occasionally and in short episodes), the LED’s “useful life” (as defined above) should be 50,000 to 100,000 weeks – that is, between one and two thousand years. Much of the literature states that in a typical installation, an LED should perform for 50,000 to 100,000 hours before its light output falls to 50% of its initial output. Instead, what typically happens to an LED is that its light output extremely slowly, and extremely gradually, declines with use. When we say that an incandescent lamp is “dead,” what we actually mean is that its filament has suddenly and catastrophically failed.īut if we ask the same question about an LED – “How do you define when the useful life of an LED is at an end?” – the answer is not nearly that simple because an LED typically does not fail suddenly and catastrophically: There’s no filament to “burn out,” nor is there any other clear, distinct event you can point to and say that the LED is dead. When it does, the flashlight can’t complete the electrical circuit that ordinarily would flow through the filament, so if you turn on the flashlight, it does not give any light. “Burnout” occurs when the lamp’s filament (typically made of tungsten, a very high-melting but brittle metal), grows so thin and weak that it can’t support its own weight, especially if it is jarred. The “burning out” of an incandescent lamp is a sudden, catastrophic, complete failure there’s no mistaking it when it happens. It starts with answering a preliminary question, which is, “How do you define when the useful life of an LED is at an end?” With an incandescent lamp (either a vacuum or gas-filled xenon or halogen lamp based on the product selected) (filament) lamp, this question is so easy that nobody even asks it: The life of an incandescent lamp is over when it burns out. The explanation for these statements is a little complicated. In normal use, the LED should last for the life of the owner and should never need to be replaced.
How long should an LED last? What is its “life expectancy”?Ī MAGLITE® flashlight’s LED light engine is a permanent component, not a “perishable” or “consumable” item like a battery or an incandescent lamps (either a vacuum or gas-filled xenon or halogen lamp based on the product selected).
We have noted variation in the quality of NiMH rechargeable batteries on the market, and if you choose the best-quality NiMH batteries you might find that any performance shortfall is, for your purposes, not meaningful.īottom line, if you are willing to tolerate a possibly significant decline in flashlight performance, there is no reason you can’t substitute rechargeable NiMH batteries for (non-rechargeable) alkalines. (For example, ANSI Light Output may be lower, and/or ANSI Run Time may be shorter with rechargeable batteries.) The degree of difference is hard to predict. You should not, however, expect the flashlights’ performance to be consistent with our published ANSI data if they are operated with rechargeable batteries. That said, the flashlights will operate with NiMH rechargeables, and use of NiMH rechargeables will not harm the circuitry nor otherwise damage the flashlights in any way. Also, the discharge curves of NiMH batteries typically differ from those of alkaline batteries – so the two battery types may behave differently under load. NiMH rechargeable batteries in these sizes typically have a somewhat lower nominal output (1.2 volts). We do this because the designs of these flashlights are optimized for use with (non-rechargeable) alkaline batteries.Īlkaline AAA, AA, C and D batteries standardly have a nominal output of 1.5 volts. All of our published ANSI-standard performance data (Light Output, Beam Distance, Peak Beam Candlepower and Run Time) are based on testing with alkaline batteries and when we ship these flashlights with batteries, the batteries we include with them are alkaline. With the exception of the MAG-TAC® flashlight that runs on lithium CR123 batteries, all of Mag’s non-rechargeable LED flashlights operate on AAA, AA, C or D-cell batteries.
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