Fenix BT20 high intensity lightweight bicycle light with dual distance beam pattern

If you’ve heard of Fenix, it’s likely for their tactical flashlights that are very well respected among flashlight connoisseurs. Now, they’re entering the bicycle light market with a pretty good looking, unique offering.

The Fenix BT20 brings a couple of new ideas to the game. The main one is the dual distance beam, which uses special optics to shape the light pattern much more so than we’ve seen from other brands. The pattern paints a broad crescent over the front wheel, then a broad beam pattern farther out for overall visibility. When aimed properly (on the handlebar, anyway), it cuts the beam off below eye level of anyone in front of the bike, so it shouldn’t blind oncoming traffic or pedestrians.

The other interesting feature is the battery. Or, rather, the lack thereof…

The BT20 comes with an empty battery case. The standard model fits two 18650 batteries or four CR123A batteries, but doesn’t include them. Fenix’s Bob Hsieh says this lets the customer pick their own, which isn’t a bad idea for a couple reasons. First, it keeps the cost of the light down. The BT20 retails for just $97 and pumps out 750 lumens for some pretty good run times:

  • High – 750lm for 2 hours
  • Medium 1 – 450lm for 4 hours
  • Medium 2 – 300lm for 6.5 hours
  • Low – 100lm for 21 hours
  • Flashing mode – 350lm

The second reason, Hsieh says, is that it’s targeted toward their existing flashlight customers who already have their own rechargeable batteries. Regardless, you can pick up 18650 batteries (which are essentially the same size as AA but more powerful) online pretty cheap. With charger, they’re generally well under $40.

Why is this a good thing? Because those run times are based on a 2600mAh battery pack. We spotted batteries with 3000, 4000 and 5300 milliamp hour ratings, which should give you a LOT more run time for only a couple bucks more. That, and they’re small and light, so throwing a couple extra batteries in your pack or pocket carries no penalty.

Fenix also sells batteries and chargers if you want to keep it all in the family.

The Fenix BT20 uses a neutral white Cree XML LED bulb for a color temp that should make for good contrast on the trail. The video below has a few pretty good examples of the beam pattern and brightness:

The case and battery compartment are highly water resistant, rated to withstand “heavy rain”. Another nice feature is a color-coded power button that lets you know when the batteries are getting low. It’s green when everything’s good, blinks red when they’re below 50% and turns solid red when remaining charge is under 20%. Inside, they use intelligent memory circuitry and heat management to shut things down if they get too hot. Outside, the back half of the light is a heat sink to prevent that from happening.

If you, like us, prefer mounting the light on your helmet, here’s the last best part: System weight is just 115g without batteries!

Don’t need quite this much light? There’s also the BT10, which has half the lumens (350 max) and comes with a 4-AA battery case.

Both models include three quick-mount O-ring handlebar mounts for different size bars, a helmet mount, battery case  and mount, and extension cable. Later this year, they’ll release the BK series, which will include batteries and chargers, but they’ll cost more.

For now, their bike lights will be distributed through their regular flashlight distributors, which means you may see them in REI, among others. In the future, they may look into specialty IBD distributors.


  1. Funny thing about Chinese lights, they can “rate” them at any lumen they want. Got a 300 lm light that lasts a year? No problem! Just print 750 on the box and ship it to the States.

    All that aside, this is the best part of the Fenix site (thanks for the link BikeRumor):
    ” Limited lifetime warranty. If problems develop after 24 months of the purchase date, we will charge for parts. The total repair fee is assessed according to the cost of the replaced materials, If damage to the light is substantial, Fenix will contact distributors with a quote who should contact the customers and customers will decide whether to exchange the parts or not. Freight should be paid by distributors or customers.”

    So the “warranty” is, you pay to have it fixed + the shipping to and from China. I love it!

  2. First off, 18650’s are 4mm thicker and 15mm longer than a AA battery, they are quite a bit larger. Second, the highest capacity 18650 cell that I have seen is a 3100mah, not 5300! Cells of that high capacity just don’t exist. But, pricing is right. $40 will get you a few cells and charger.

  3. any notion what the battery case will weigh when loaded with batteries? I love the notion of lights with better beam shaping, but at $97 plus $20-40 for batteries, we are in the same price and output range as the many stand alone lights on the market. I hope Fenix has a self contained option in the pipeline as well. That would be a great answer to something like the new Taz models from Light and Motion.

  4. Cory – Google “18650 battery” and you’ll find plenty of options over 3100mAh. Whether those battery’s output is legit or not is another story.

    Zombinate – keep in mind that a “spare” battery would be under $10 or so, which is way cheaper than model/brand-specific options from others. The all-in-ones are great for handlebar use, but tend to be a bit big and heavy for helmet use, which we prefer for trail riding.

    All – As with anything we post here, we’re just showing what’s out there, and we’re hoping to get one of these in for a test this fall.

  5. The “dual beam” like system is pretty much what Busch Muller has been doing for years now.
    I haven’t decided yet if I like Fenix’s battery options or not.

  6. I like it. I have a 240-lumen light and it’s plenty bright enough though the beam could be broader. This looks like it’ll make it to my 2013-summer wishlist.

  7. You are not quite accurate regarding the MULTI distance focus. While dual only means “2” and maybe techicallly correct Light and Motion Seca lights used two rows of LEDs to give a flood pattern and then a distance pattern. Although the been spread on the Seca is much more even it was a dual focus been pattern released quite a number of years ago.

    Also, the was not a picture of any if included frame mount for the battery?

  8. “it cuts the beam off below eye level of anyone in front of the bike, so it shouldn’t blind oncoming traffic or pedestrians.”

    Wait, I thought the whole point of a front light was to blind people so they will get out of your way. At least that seems to be the thinking of a good 2/3 of the people who ride on the Burke Gilman trail here in Seattle.

  9. Just a bit of clarification on the first comment posted by Donny. All Fenix flashlight Lumen counts are based on international ANSI standards, not a random number assigned. So that clarifies your comment on Lumens. The 24-month warranty is just that. We are one of three authorized Fenix Warranty Centers in the US, and we repair lights with no questions asked during the first 24 months (or 30 months if the customer registered his/her light). After that, the average cost to repair a Fenix light (IF we charge at all) is about $10 total to the customer. Also, we are in Oklahoma, not China. That clarifies your comments on the warranty. To further support the quality of a Fenix product, we ship thousands of lights a month and our return/repair rate is less than 1%. We hope you take the opportunity to check into a Fenix product in the near future. Fenix Outfitters and Fenix Store. Thank you, Bike Rumor, for your review of the Fenix BT20.

  10. I have the 720 lumin bx20. Love it!!! It is bright and I can never out ride the light. (Max speed 53 mph at night). The mount is great. I have flat bars, it’s doable, but better on helmet. Use it for road biking. And have a hat that I made to mount as well for hiking, camping.
    Love it with the batteries (rechargeable) I was told over 1000 charges for the batteries.

What do you think?