"LED" stands for "light-emitting diode". LED technology is now available in flashlights.
The LED Advantage
LED bulbs hardly ever need to be replaced. LED design and integration company LEDdynamics says that LEDs can sustain up to 100,000 hours (eleven years) of use.
LED flashlights (known as torches in some countries) last longer between battery changes. SureFire offers their 6P flashlight in both LED and incandescent versions. The LED version is over twenty percent brighter, yet lasts eleven hours on a pair of 123A lithium batteries versus one hour for the incandescent.
LED Brightness - Lumens versus Watts
More LEDs doesn't mean brighter. A one-LED flashlight can be brighter than a flashlight with ten LEDs.
Total brightness is measured in lumens. Ten to a hundred lumens is common.
- Ten lumens is decent.
- Thirty lumens will be bright enough for most purposes.
- "Tactical" police flashlights are about ninety lumens.
LEDs are also measured in watts. This is the power input, not the brightness output. Most general-use flashlights top out at one watt. Ninety lumen police flashlights are typically three watts.
It is difficult to compare lumens with watts. Manufacturers claim anything from ten to eighty lumens per watt (manufacturers probably report the rated wattage of the LEDs, not the actual wattage driven by the electronics). Average claim is about thirty lumens per watt.
So, brightness is best compared using lumens, not watts. However 30 lumens per watt can be assumed if lumens are not stated.
Dimmer can be Better
The lowest brightness of a flashlight is important. Dim light is
- good for conserving battery life (super bright also means super battery-eater)
- more comfortable for reading at night
- less likely to wake up companions when rummaging around in a tent
Premium flashlights have a low and high power setting. Some have more than two levels of brightness. Others have a separate red LED that not only conserves the battery but also protects night vision.
An alternative is to carry two flashlights, one dim and another bright (much like carrying a pocket knife and a machete). This is practical with today's lightweight flashlights. A backup flashlight can be a lifesaver.
Batteries
AA batteries are best.
Small, bright LED flashlights can be powered by one or two AA batteries. These are the best all round performers (cost, capacity, availability) for general portable use. A single AA alkaline can power a flashlight for hours.
AA batteries have wide market support. There are
- alkalines
- lithiums (lightweight, last longer than alkalines, work well in the cold, expensive)
- NiMH rechargeables
AAA batteries are the next best. Flashlights with three AAAs are a popular configuration.
Specialized batteries such as button cells or 123A lithiums should be avoided. 123A batteries may give good performance, but replacements can be difficult to obtain in remote areas.
Batteries are part of an overall portable power supply plan. Equipment that use the same battery type (GPS, camera, flashlight, MP3 player, radio, walkie-talkie) can share batteries in a pinch. Solar chargers for AA and AAA batteries are available, making these batteries even more attractive.
Upgrading to LED Flashlights
LED flashlights are overwhelmingly superior to traditional incandescents.
With LEDs, a backpacker
- need not worry about bulbs burning out
- can carry up to ten times fewer batteries
This translates into better safety and a lighter backpack. Aside from the higher initial cost, there is no downside.
