Run time is an important characteristic to consider when shopping for an LED flashlight or headlamp. Run time describes how long a flashlight or headlamp will operate on the same set of batteries.
Different consumers value run time for different reasons. An avid fisherman, for instance, could buy flashlights based on run time because he doesn’t want to have to change out batteries on one of his weeklong fishing expeditions. Backpackers appreciate long run time as well – after all, who wants to scramble for a new set of batteries in the dark? In general, run time speaks to a flashlight’s efficiency – well-designed models will be able to run longer.
How Run Time is Measured
Before 2009, there were no universal ratings for assessing the characteristics of flashlights, which made it challenging for consumers to properly compare different models. The difficulty became especially dire once LED flashlights hit the market.
Compared to a traditional incandescent flashlight, an LED flashlight could shine much farther, for a longer time and using fewer batteries. Yet no universal system was in place to clue in consumers about these differences. Recognizing the need for a standard list of flashlight performance indicators, a group of incandescent and LED flashlight manufacturers joined together to create the standards that would be officially adopted by the American National Standards Institute and the National Electrical Manufacturers Association in 2009.
Known as the ANSI FL1 standards, these guidelines are strictly voluntary; flashlight manufacturers are not forced to display the ANSI testing logos. However, because consumers are often more willing to buy products that are easy to compare, many manufacturers have chosen to display the ANSI symbols on their packaging. Manufacturers test their own products according to the ANSI FL1 standards, using specific procedures.
Overall, the ANSI FL1 standards describe light output, beam distance, run time, peak beam intensity, impact resistance and water resistance. Each characteristic has its own unique symbol for flashlight packaging. The ANSI FL1 logo for run time looks like a clock; underneath is displayed the number of minutes or hours an incandescent or LED flashlight can run on a single set of batteries. The length of run time is defined as stretching from full power to 10 percent of a flashlight’s original light output.
If you’re shopping for a high-intensity flashlight or headlamp, the official ANSI standard is the same, but some manufacturers have chosen to measure run time differently, for the primary reason that 10 percent of original power can be quite bright in a high-performance headlamp or flashlight. For instance, a high-intensity headlamp could blast 350 lumens at full power; 10 percent of that would be 35 lumens, which is still a very serviceable amount of light. In other words, some headlamp and flashlight manufacturers believe the ANSI standard does not adequately describe how long their products can provide a helpful amount of light.
These manufacturers instead determine run time according to how long each torch can provide the light of the full moon at a distance of two meters. This may seem random, but studies have found that adventurers can typically operate in emergencies with this amount of light on the pathway in front of them. Two meters is the distance between headlamp and terrain, according to the average height of American men and women.
Factors that Influence Run Time
There are many different factors that can impact an LED flashlight’s run time. Here’s a look at a few:
Flashlights with multiple brightness settings will run out of juice sooner if the brightest setting is used. Manufacturers typically measure run time on the brightest possible setting, which means you should be able to extend a flashlight’s run time by selecting a lower brightness setting.
Batteries perform differently in extreme heat or cold. This sort of information isn’t typically listed on LED flashlight or headlamp packaging, but it’s a good thing to keep in mind while using your torch.
More batteries will be able to sustain a longer run time. Larger batteries will provide more power for longer performance. LED flashlight designers make tradeoffs between run time, product weight and high battery costs for the consumer. As you choose an LED flashlight, notice how many batteries each model requires.
Number of LED chips.
More LED chips means brighter, more powerful light that can reach farther into the darkness. However, the more LED chips an LED flashlight or headlamp has, the more power is required to sustain run time.
A final word of warning when considering run time: Be careful not to confuse LED life with run time. LED life describes how long the LED bulbs in each flashlight will be able to operate. The bulbs in an LED flashlight, for instance, could run for 50,000 hours. However, that does not mean that they will run for 50,000 hours on a single set of batteries.
For a fair comparison of run time, compare LED flashlights using the ANSI FL1 Standard for run time. If the headlamp or LED flashlight you’re considering doesn’t display the ANSI standard, see if you can find a comparable measurement, such as the number of hours the product will run until its output equals that of the full moon.