Select your localized edition:

Close ×

More Ways to Connect

Discover one of our 28 local entrepreneurial communities »

Be the first to know as we launch in new countries and markets around the globe.

Interested in bringing MIT Technology Review to your local market?

MIT Technology ReviewMIT Technology Review - logo

 

Unsupported browser: Your browser does not meet modern web standards. See how it scores »

Looking for a last-minute stocking stuffer? Technology improvements and cost reductions in LEDs (think indoor lighting) and lithium-ion batteries (think laptops and electric cars) are making for some very interesting—and unusual—flashlights.

These flashlights are dramatically brighter than any non-LED flashlight that I have ever used. The light comes from high-intensity devices such as the CREE XLamp XM-L. The XM-L can draw as much as 10 watts of power, which produces 1,040 lumens of output. That’s considerably brighter than a 60-watt incandescent bulb (which produces 800 lumens), but all of the light is collimate in a flashlight, so it’s more like a traditional outdoor floodlight.

Unlike the bulb in traditional flashlights, the CREE LED needs some electronics to drive it properly. Flashlight vendors have not passed up the chance to gild the lily. Most of the flashlights that I’ve tested offer up to five different modes: high, medium, low, flashing, and SOS (three short flashes, three long, and three short again, corresponding to Morse code). Annoyingly, there’s only a single switch, so you need to repeatedly press the button—10 times!—to cycle the between all the modes.

Most of these flashlights are based on the 18650 battery, a 3.6-volt lithium-ion battery that’s a little longer than a traditional D cell and a little wider than an AA. The 18650 is best known for its use in Tesla’s racers, but it was previously used in laptops. Cars and laptops use multiple 18650s with solder tabs wired together. For flashlight use you get batteries with a button and flat top, just like a traditional flashlight battery. The 18650 requires a special charger; you can buy four generic 3,000-milliam-hour batteries for $7.86 on Amazon; each packs roughly the same power as two high-capacity rechargeable AAs. I bought a set of generics and had one fail, so be sure to buy a few extra.

Some of flashlights can run on either a lithium-ion or standard alkaline AA or AAA batteries—useful for an emergency light you might leave in your car, since alkaline batteries can hold a charge for years. In my tests I got anywhere from two to six hours of continuous use on a flashlight depending on the mode. Frequently I could turn the flashlight off for a few hours and then get a few more minutes of high-power output when I turned it back on. Like conventional flashlights, the LEDs will slowly fade as you use them; be sure to have a spare pair of charged batteries ready to go.

There are quite a few of these flashlights on the market now from a variety of manufacturers. Items of differentiation include the number of modes, the zoom lens (from spotlight to wide-angle), the brightness of the LED, and the number of batteries.

I bought a selection of the flashlights from Amazon and tried them out. I don’t have a lumens meter, so the specs are from the website.

UltraFire CREE XML-L T6This flashlight with a bronzed tip and five modes weighs 140 grams and is 13 centimeters long, so it fits nicely in the hand. It comes with a wrist strap. The CREE T6 bulb produces 1,800 lumens. I got more than five hours of output on low, which was still plenty bright.

Ultrafire W-878This versatile flashlight can be powered by an 18650 battery, a 26650 battery, or three AAA batteries. (The 26650 is larger still than the 18650 and packs 5,000 milliamp-hours or more.) Five modes, 196 grams, 14 centimeters lomg, with wrist strap. Reportedly delivers 1,000 lumens.

Trustfire TR-3T6 This frightening flashlight can hold two 18650 batteries for 76 minutes of full-intensity illumination, or three batteries for 115 minutes with an extension tube. Max output is 3,800 lumens from three XM-L T6 LEDs, which in my case was bright enough to light up an entire three-story house across the street. Five modes, 403 grams, 22.5 centimeters long.

Mini CREE Q5This tiny flashlight ran for more than six hours on an AA battery. I bought three of these online and got slightly different models at slightly different prices from different vendors, but they’re all roughly $7 and reportedly put out between 200 and 400 lumens. Mine have just on and off modes, although the website claims high, low, and flash. The light weight (87 grams) and small size (9.5 centimeters) make these units easy to keep in a backpack or handbag, but they are so small that they could easily get lost in a glove compartment.

All of these make great stocking stuffers. Just don’t let the kids shine them in people’s eyes up close. These lights are bright, and at least one comes with a warning sticker similar to what’s found on a laser pointer. Currently, though, there appears to be no generally accepted safety standard.

0 comments about this story. Start the discussion »

Tagged: Computing, Energy, lithium-ion batteries, LEDs

Reprints and Permissions | Send feedback to the editor

From the Archives

Close

Introducing MIT Technology Review Insider.

Already a Magazine subscriber?

You're automatically an Insider. It's easy to activate or upgrade your account.

Activate Your Account

Become an Insider

It's the new way to subscribe. Get even more of the tech news, research, and discoveries you crave.

Sign Up

Learn More

Find out why MIT Technology Review Insider is for you and explore your options.

Show Me