# Using LED flashlights for cycling



## DennisF (Nov 4, 2011)

I mentioned in another post that I was using LED flashlights for night riding. Someone asked for details, so here they are.

I have always enjoyed playing with flashlights. So when I wanted to go night riding, I researched using flashlights as an alternative to dedicated bike lighting. It turns out that everything you need can be easily purchased, at a substantial savings over good bicycle lights, and you have good flashlights to use when not riding.

There are other advantages. Most dedicated bike lights have the charging circuitry built-in. I prefer the simplicity (and weight savings) of having a separate charger. Extra battery packs for dedicated bike lights can be a major expense. The manufacturers are generally not forthcoming with the cost of extra batteries. An extra Li-ion battery is only about $2.

I limited my search to LED flashlights using rechargeable Lithium Ion batteries. This is the same technology used in high-end rechargeable bike lights. Li-Ion provides the highest power density -- in other words, the most electricity for the least weight. 18650 is the most popular size of Li-Ion cells. It is the size used by most Li-Ion flashlights, as well as most notebook computer battery packs, and even the battery pack in the Tesla electric car. I saw some battery packs made for a dedicated bike light that are obviously 18650 cells placed in a fancy shell and given a fancy price to go with it.

Everything reviewed here was purchased on eBay. Price estimates include shipping. I do not link to specific items as listings disappear frequently. Just search and you will find it.

BATTERIES

Get several non-protected 18650 cells. I use two flashlights, and carry two spares for each. The cells cost about $2 each -- cheap by bike gear standards, so get several.

There are two types of 18650 cells -- protected and non-protected. Lithium cells cannot be totally discharged. If they are drained below a certain point, they are ruined. Most devices that use Li-Ion have circuitry to turn themselves off when the batteries get low. Your notebook computer is a prime example. However, not all devices have this feature, so cells with built-in protection circuitry are available. I know of at least one dedicated bike light that requires protected cells. 

Protected cells are not prohibitively expensive on eBay. However, the protection circuitry is fragile and something else to go wrong. The listings for the flashlights usually do not state that they have protection built-in. However, the package deals include non-protected cells. I have corresponded with sellers who clam that the flashlights do have protection circuitry. When the batteries get weak, the light dims a bit, then starts flashing. But I have not tested by leaving it on overnight.

Get some cases for the batteries. The batteries are somewhat fragile. I damaged the internals of one by dropping it on a ceramic tile floor. You don't want to just have them rattling around in your pack or toolbox either. They contain a lot of energy and could explode or start a fire if they get shorted. I got 6 cases that hold 2 cells each for about $3, but typically they cost nearly a dollar each.

CHARGER

Cheap chargers for Li-Ion abound on eBay and Amazon. It is typical to find a package deal of a flashlight, two 18650 cells, and a wall-brick charger for < $30. While these chargers will charge the battery, they are slow (8 to 12 hours vs 2 - 3 hours), and probably do not charge the batteries according to specifications, compromising battery life and possibly safety. Charging Lithium batteries is much more complicated than charging Nickel-Metal Hydride, so a good charger is a must. 

There are web sites devoted to Li-Ion flashlights, with reviews of chargers. According to my research, the one to have is made by Pila. It is a 2-channel (capable of charging two batteries at once, each with its own independant current regulation) charger and costs around $50. The XTAR WP6 II got good reviews also. It is a 6-channel charger, and costs only about $35. It can be powered by household current or from the cigarette lighter socket of your car. Be sure to get the II model -- it has a better charging algorithm and a better system for handling different-size cells. A note on this charger -- it will charge fastest if you only put one cell in each group of two slots.

There is also a WP2 II model that charges only two cells, and costs about $20. Again, be sure to get the II version.

FLASHLIGHT

Now for the part we have all been waiting for.

THE Li-Ion flashlights to own are made by Fenix. However, they can run $50 or more. Excellent-quality aluminum flashlights using the respected Cree brand of LEDs abound on eBay and typically cost a little under $20. Just search for "18650 flashlight 1600 lumens" and the like.

The first option to consider is if you want a one or two-cell light. I chose one-cell for weight savings and ease of battery management. Rechargeable batteries used in pairs should be kept together and charged together for maximum life. You don't want to mix an old cell and a new one. One-cell lights are plenty bright. On the other hand, the 2-cell is even brighter and burns longer.

Single-cell lights usually have adapters that permit using either a single 18650 or three standard AAA cells. I have never tried the AAA option. Runtime would be a lot shorter due to the lower energy density of alkaline or Nickel-metal Hydride cells.

Another feature to consider is whether or not the light has a zoomable (adjustable-focus) beam. Zooming is accomplished by sliding a lens holder in and out. I don't use the zoom feature much while riding -- I just leave them at max width. However, I really like the even beam pattern of these lights. Some weight savings could probably be had by using a non-zoomable light, However, I have never seen a non-zoomable 18650 light to see the pattern it makes, and I do use the zooom feature when using it as a regular flashlight.

Most if not all 18650 flashlights feature multiple brightnesses and flashing modes. These lights are BRIGHT. Turn one on and point it at the ceiling while in a dark room in your house, and the whole room is lit up enough to easily read. When biking, battery life is extended by not using full brightness, and there is still more than enough light to ride. When using them for typical flashlight tasks in the shop or home, full brightness can simply be too bright.

(A note about lights with adjustable brightness and wireless cycling computers. This applies to the flashlights as well as cycle-specific lights: Partial brightness is achieved by rapidly strobing the light on and off. It's fun to watch the tread on your front wheel appear to stand still or rotate slowly backwards as you blast thru the woods. This rapid switching can result in radio interference to the computer. I have not had this problem with my flashlights and Cateye Strada computer. If you have a problem, use full-brightness or try moving the light and computer further apart).

I will describe the flashlights shown in the photos. The long one in the first photo is a 2-cell and just used around the house. The short one is a one-cell. Both lights feature three brightness levels and two flashing modes (one mode is a rapid flash which I have used as a taillight when riding on the road at night. The other sends S O S in morse code. 

The two-cell has the switch built into the tailpiece. The one-cell has it built into the body. The tailpiece switch is definitely superior. The one-cell had a rubber bulb over the switch that made it difficult to turn on and off, so I removed it. Water resistance has been compromised, so I turn it downwards to keep rain out and it has been fine.

The light on the helmet is also a 1-cell, but has the switch in the tailpiece. It is a more durable light. It is also lighter than the other 1-cell (180 vs 220 g with battery). However, it has only two brightness levels. Low brightness is between dim and medium on the other 1-cell. When riding with two lights, I put the helmet light on low and the handlebar light on medium. If I were riding with just the helmet light, I would run it in bright mode.

There are now one-cell lights with three brightness modes available, similar to the one in the first picture, but with the switch on the tailpiece.

Another advantage of a tailpiece switch -- it it ever failed it should be easy to bypass it.

A hint to make flashlights more reliable and prevent bad connections that can cause the flashlight to flicker when shaking it. Get a tube of white lithium grease from the auto parts store. Lightly coat the battery and flashlight terminals (including the bulbs of flashlights that have removable bulbs. LED flashlights have the LEDs soldered permanently in place), as well as the threads on the tailpiece and anything else that screws together. Also a good idea for any electrical connection, especially the tail and brake lights in your car.

MOUNTING BRACKET

There are a number of handlebar clamps available. The best ones seem to be one made by Fenix. They look heavy-duty, and swivel for more mounting options. Cost is about $15. I was going to order one, but decided to try some eBay ones first (pictured). Cost about $2 each. 

The one on the left swivels, and is made of hard rubber. There is a rivet in the center that was scratching my handlebar. That was easily fixed with a piece of tape. However, it just wasn't solid enough for my tastes. It would be more than adequate on the road, but would occasionally jostle out of position.

The mount on the right is great. Very solid. It comes with two thicknesses of bushings to accomodate different diameter handlebars. I needed to use the thin bushing, and it was a little too loose. I fixed it by using weatherstripping cement to fasten a piece of innertube to the mount, behind the bushing. It is now bulletproof. Weight is 35 g.

SUMMARY

It took a little research and trial-and-error, but I have a good lighting system with two lights, for less than $100.


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## MXRider72 (Aug 10, 2010)

I use a 170 lumen Surefire for my night rides. Runs on 123 cells and the light itself is bomb proof. I use zip ties and strap it to my helmet, but I'm looking at making a mount for it that is more durable and has a quick detach so I don't have to use the zip ties. 

When the new 500 lumen Surefire X300 ultra comes out I'm gonna try that out, but I'm worried battery life won't be what I need. With my current setup I get almost two hours of useable light. 

Sent from my PC36100 using Tapatalk 2


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## DennisF (Nov 4, 2011)

Ok, I forgot about Surefire when I mentioned Fenix. Thanks for mentioning yours. EXCELLENT lights! Are you using rechargeable batteries? 

Does the 500 lumen X300 have a low setting? If so you will have the option of a brighter trail or the long life of the one you are getting now. Or just cary spare batteries -- a lot if you need to. 4 CR-123/16340 cells fit in one case that holds two 18650s, and they are cheap enough.

I have heard of guys using velcro strapping instead of zip ties. In my case I don't care about removability -- the helmet is a spare I had and the flashlight cost only about $15, so I can dedicate it to that. Maybe use the new Surefire as your main light and mount it on your handlebars and get a cheap 16340-sized light or use your old Surefire for your head. My wife has a cheap Chinese single-cell 16340 light that is brighter than my 18650 on medium, but the battery life sucks. It has a low mode that is quite useable as a flashlight, but I wouldn't want to ride very far with it on low.


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## MXRider72 (Aug 10, 2010)

No, I use standard 123 cells, I usually buy them in cases because a lot of my shooting equipment uses the same batteries. Makes life easier. 

The X300 doesn't have a low setting, but the fury does. It has either a 15 or 25 lumen setting, and 500. That is a standard hand held type flashlight whereas the X300 has a weapon rail mount built in with a quick release. My thinking was I could use some double sided tape and mount a small section of picatiny rail to the top of my helmet that way I could easily remove it for daytime use or to change the batteries. 

For battery storage I use a small water tight case I got at a surplus store. It holds 4 batteries nicely and I use a piece of foam to keep them from rattling around. I keep this inside my camelback mule along with my tools and some extra gear. 

Sent from my PC36100 using Tapatalk 2


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## zemike (Sep 3, 2007)

That's a lot of text but 1 beamshot is worth 1000 words.

This is a beamshot on MTBR settings of the Easy2Lite flashlight
Cree XM-L neutral white 3-mode 400 lm bike flashlight (OP reflector, 18650 cell) | eBay









Control:









High:








Distance to the building is 120 meters


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## mattthemuppet (Jul 16, 2004)

using flashlights for nightriding has its pluses and minuses, but what ever you do, don't skimp on the 18650 batteries and *don't* buy them off eBay. eBay and a lot of Chinese retailers are flooded with fakes, rewrapped recycled laptop cells and even Russian doll-style "tiny li-pos in a 18650 shell" batteries. At best you'll get a fraction of the capacity on their label (the 2 I bought from eBay for testing got ~800mAh from 2500mAh Uniquefire cells), at worst you'll have a potential fire or explosion risk.

Even the lower rated brand name (such as Xtar 2600) will have more than twice the capacity for only $6-7. Cheaping out just doesn't make sense.


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## DennisF (Nov 4, 2011)

Thanks ZMike -- that about says it all :thumbsup:

Matt, I don't disagree with what you say. You have me questioning the wisdom my purchase . No question, a name brand, Samsung etc. is the best. The only way to be sure you are getting a good cell is to buy from a reputable supply house, not eBay or Amazon. Even if you pay $6 per cell for a name brand, there is no guarantee that they are real.

OTOH, the $2 cells are working fine, and tests indicate that some cheap cells are decent. I don't have the equipment to test them, but I am getting more than any 800 mAh from them. I charge them in a place where it won't start a fire if they blow -- which I do with "good" cells as well.

18650 battery test with capacity curves for many cells

What is dusturbing is that NONE of the cells produce the rated power :madman:


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## mattthemuppet (Jul 16, 2004)

yeah, battery makers are often more than a little free with the truth when it comes to capacities, although all the Panasonic batteries I've bought (25 odd, of different models) have been bang on or higher than their rated capacity. The last one I bought was from CNQualitygoods, although there are plenty of different sellers. Another thing to bear in mind is that capacity goes down with increasing discharge rate - cells are rated at at 0.5 or 1A discharge and all but the latest NCR18650B cells drop 10%+ capacity at 2A and higher. That's also for high quality cells - the cheaper ones (like the decent Trustfire and Ultrafire ones I've bought) just fall off a cliff over 1.5A each.

Sounds like you're treating them with respect, which is reassuring. I'd just recommend picking up a couple of the Panasonic NCR cells (protected or not) when you next feel the need to treat yourself. They'll make a big difference to runtime and how long your lights stay at their rated output, then you can keep your others for backups


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## wquiles (Aug 22, 2010)

mattthemuppet said:


> yeah, battery makers are often more than a little free with the truth when it comes to capacities


Well said Matt :thumbsup:

Same with the LED drivers - many vendors will quote unrealistic Amperage outputs, plus the efficiency might be fairly low, they heat-up too much/too fast, and the output goes down dramatically as they warm up.

Most of the time you get what you paid for


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## katoom400 (May 6, 2010)

trying to get setup for night riding on the road, was looking at either the niterider lumina 650, or the cygolight expilion 700, both are around $140, then I came across this thread and I'm intrigued about just using the torch light setup for considerably less $$, I don't like the idea of buying stuff on ebay from Chinese sellers, but found this one locally, would this work for my purposes? or is there something else I should be looking for?

this is the ebay item #: 330795293084 (mtbr won't let me post links yet)


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## DennisF (Nov 4, 2011)

1600LM Lumens CREE XML XM-L T6 LED 5 Mode Focusing Zoomable Flashlight +18650 | eBay

That looks exactly like the two-cell one in my photo. It is the best light of the three, and is a real torch. For cycle use, it's fine on the handlebar. I'd prefer something lighter for my helmet  It's 285g incl batteries BTW.

I got the charger from eBay, but it actually came from a seller in California. The cells can be had from numerous US sources -- as MattTheMuppet says, it wouldn't hurt to spend more than $2 each like I did. You can get two sets at $7 ea and still save a lot over your original plan.

You can get the Fenix handlebar mount from Amazon.


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## katoom400 (May 6, 2010)

cool, thanks for the quick response. how about the 1600 lumen light rating...seems a little high considering I'm seeing the fenix lights with much lower lumen ratings going for 5 X the price? what kind of light should I expect out of this $20 torch? and should I go with two of them, or is 1 fine for street use in a rural neighborhood?

Thanks,
Andy


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## MXRider72 (Aug 10, 2010)

In my experience, many of the cheap Chinese lights claiming high lumen outputs don't put out anywhere near what they claim. With regard to flashlights, you really get what you pay for. 

Granted I'm a Surefire whore and am very biased towards them over other brands out there.

Sent from my PC36100 using Tapatalk 2


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## katoom400 (May 6, 2010)

MXRider72 said:


> In my experience, many of the cheap Chinese lights claiming high lumen outputs don't put out anywhere near what they claim. With regard to flashlights, you really get what you pay for.
> 
> Granted I'm a Surefire whore and am very biased towards them over other brands out there.
> 
> Sent from my PC36100 using Tapatalk 2


looks like a 500 lumen surefire is $150, at that point would I be better off looking at the niterider 650 or cygolight 700? or are their lumen rating way off also?


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## DennisF (Nov 4, 2011)

The 1600lm rating is probably on the generous side, but it is still BRIGHT. One is plenty bright to ride on any terrain. I ride all the time in the woods under deep canopy cover, wearing the same yellow-lens shooting glasses I wear in the daytime. You would normally run it on medium brightness, and use hi for the really technical stuff. It is brighter than most of the dedicated bike lights I see people using.

I use two not for brightness, but for softer shadows and to have a backup. I have never had one fail in my year's experience with them, but they probably aren't as reliable as a Fenix or Surefire would be. But nothing is failproof.

BTW the pattern is perfectly round and even on full-wide. As you zoom to a narrower beam a halo forms, and at max narrow it actually projects a square image of the LED -- done on purpose for wow factor I expect. If you want an even, narrow beam just zoom out a little.

In comment to MXRider72's post: I don't see how a cheap vs expensive flashlight, or a dedicated cycling light for that matter, using the same make and model LED and the same voltage are going to have substantially different overall brightnesses. The only point of variation would be the lens or reflector which would affect pattern more than brightness. For the price difference I can live with a little halo 

If I were going to get another light now I would get something like this -- it appears to be a single-cell version of the same light.
1600 LUMENS ZOOMABLE CREE XM-L T6 LED 1 X 18650 FLASHLIGHT TORCH | eBay
And gotta love the price.

Somethng to check out would of be lights that aren't zoomable. They would be lighter and more compact. I just got zoomable ones because I knew they have nice even patterns.


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## DennisF (Nov 4, 2011)

katoom400 said:


> looks like a 500 lumen surefire is $150, at that point would I be better off looking at the niterider 650 or cygolight 700? or are their lumen rating way off also?


Probably not. 700 lumens that is well within the specs of the popular CREE XM-L T6 LED that the Chinese lights and lots of other stuff use. The technology certainly is there.

They don't say what LED the NiteriRider use (that I can find). The CygoLite uses something in the XM-L family.

Another important spec that is difficult to come by for dedicated bike lights is battery capacity. Based on the runtime of the Lumina 650 it is likely an 18650 (about 2600 mAh), but I would ask before purchase.

The SureFire P2X uses two CR123A cells (16340 is the rechargeable battery of the same size). They are about 900 mAh. It is a lot smaller light than anything that is 18650-based.
SureFire P2X Fury Defender® Compact LED Flashlight w Bite


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## katoom400 (May 6, 2010)

thank you guys for so much valuable info!

ok one more question:

this mount: New Cycling Bike Bicycle Front light Clip Torch Bracket Flashlight Mount Holder | eBay

or the fenix for 3 X the price? (it does look beefy!)


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## MXRider72 (Aug 10, 2010)

With regard to certain brands and their claims of lumens, I agree many brands are using comparable led modules. However I have seen many of these lights greatly over rated whereas Surefire consistently under rates their lumen output. Reason being, Surefire is rating their lights in a realistic manner over the batteries life, and they rate their runtimes not until dead, but until under optimal light output. 

Understand the stuff I'm using is designed as weapon lights, and are therefore more compact and lightweight. Lights designed for cycling are going to be more optimal. Only reason I am using weapon lights is because I have a lot of them and they work for me. Using them on a bicycle is just a bonus. 

Sent from my PC36100 using Tapatalk 2


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## DennisF (Nov 4, 2011)

katoom400 said:


> thank you guys for so much valuable info!
> 
> ok one more question:
> 
> this mount: New Cycling Bike Bicycle Front light Clip Torch Bracket Flashlight Mount Holder | eBay


It looks like the same one I use.

Be prepared to do a little innovating with rubber bushings. The two-cell 18650 flashlight barrel is smaller diameter than the single-cell models that also take 3xAAA, so you will probably have to put a bushing around it. Maybe the thick piece of rubber it come with would work.


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## katoom400 (May 6, 2010)

all my stuff is on it's way, I'm starting with one of the 2 battery lights I posted. I went with the fenix mount and if it works out I'll order a second light and mount which will bring to about $100 including the xtar 6 battery chanrger. hopefully it will work out at least as good as one of the dedicated bike lights I had mentioned.


I also have access to a lot of lenovo laptop batteries, so I already have a host of 18650 sanyo cells that I believe are 2600mah. however I suspect they are unprotected so I don't know if I should use them.


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## DennisF (Nov 4, 2011)

Let us know how it works out for you.

I wouldn't worry about using unprotected cells. I have been told that the flashlights contain protection circuitry. I know from experience that they start flashing then go out altogether, and do not ruin the battery. If you left it in the on position overnight or longer it might damage the batteries, but I don't think it could happen in normal usage.


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## katoom400 (May 6, 2010)

got everything in the mail today with the exception of the bar mount, couldn't resist zip tying it to the bars and going out for a short 8 mile road ride at dusk...ending in dark, worked awesome on the road! at dusk I had it in strobe mode, and once it got dark I switched to high cars where even flashing me their high beams!!! ran it on med most of the ride and was plenty of light...forget about strobe at night...you'll make oncoming drivers dizzy! I have to say that was the best $20 I've spent in a long time...of course a bit more with the charger..but I don't count that. 

I have a boat load of spare cells from a surplus of new laptop batteries we had leftover at work, so I'm definitely going order another of the 2 cell lights and a 1 cell for the helmet if I decide to ride the trail at night.....I'm awaiting ACL surgery and using the road cycling as my pre-hab to get the knee strong before surgery. The torch light and a cygolight hotshot, I'm ready to ride after work straight until the snow flies! ohh the dog is going to be happy too...she get's to do 4 miles with me on the road before I get my prehab started every time.


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## katoom400 (May 6, 2010)

quick update, I just got the fenix af02 mount and it is beefy....and heavy!!!!

unfortunately I think it is not going to work out well, seems like it will clamp just fine, but the 360 degree rotation is a bit too loose....it turns very easy and seems a bit sloppy......I may return it in favor of some of the less expensive mounts.

here is a crappy cell phone video of the crappy mount:

2012-10-04_18-42-50_83.mp4 - YouTube\

a little searching on google, a trip to Lowes $4 later I have this:




























not the stealthiest or sano mount...but it is 100% functional for 700% less $ than the worthless fenix mount.


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## DennisF (Nov 4, 2011)

I got one of these, a single-cell 18650. Three brightnesses, switch on the tailcap, about $13.50 delivered.

It fits my handlebar clamp perfectly. My other one mentioned in my first post, with the switch on the side, required removing the tailpiece to install the handlebar clamp.

Weight: 175g with battery.

This is the one to get!

1600 Lumens Zoomable CREE XM L T6 LED 1 x 18650 Flashlight Torch | eBay


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