Pinnacle Flashlights Blog

Have you ever purchased a flashlight which advertised that it would run for 200 hours, but when you actually went to use it only lasted for 5 hours before it became so dim that you had to change batteries? This is because the 200 hour number usually means 200 hours of “useful light” which is usually defined (somewhere in fine print often not found on the package) as less than 3 lumens or so. Not exactly the same thing as 200 hours of full brightness!

The problem is, in a normal circuit, LEDs and bulbs will draw less energy from normal batteries as they get weaker and become dim as a result. This phenomenon explains the fact that cheap flashlights are reasonably bright at first, but steadily dim as less and less energy can be taken from the batteries, which end up feeding a small amount of energy to the emitters for a long time. The good thing is, many of the modern LED flashlights (and a very few incandescent) on the market use regulation circuits to balance the 5-hour and 200-hour numbers out by keeping the energy coming from the batteries at the rate it started with. This means you get more time at full brightness and less time with less brightness.

As with everything, one solution isn’t always the best one for every need. Some lights have regulation circuits which will remove practically all the energy from the batteries before allowing the brightness to decrease, which means that the light will usually go from full-power to dead with a short and very-low dim “moon-mode” before the light shuts down completely. For most situations, this is fine, and results in the best brightness for the longest period of time. However, some lights have regulation circuits that will keep the brightness the same for most of the batteries’ life, but intentionally dim the light before the batteries are completely dead to give the user a longer and brighter moon-mode. Neither setup is better, it just depends on what you want. Regardless of which you choose, an effective and efficient regulation circuit is a critical part of a high-quality light.