Flashlights & Headlamp

Flashlights and headlamps let you continue your activities once it is too dark to see. The ability to expend the hours that we can do things is invaluable. Today, virtually all flashlights and headlamps use LEDs to produce light. I strongly encourage people to retired any lights which aren’t using LEDs. LEDs are more durable, have a longer lifetime, and are more energy efficient than other options.

My Choice

I use the first generation Nitecore NU20 for most of my lighting needs. The NU20 weighs around 1oz with a homemade or litesmith band, and is quite compact. Light output 1lumens/100hours, 40/7h, 220/60min, turbo boost 360/few minutes. It can charge and run at the same time so you can use it as a remote battery headlamp with a USB power pack when you want longer runtimes or in extreme cold. Holding the button button will indicate >50%, between 10-50%, or less than 10% battery level. Output in well for regulated for low and medium output levels, the high not so much. The downsides are that the throw isn’t really up to challenging cross country way finding and you can’t quick change the battery. If I am going to do a lot of way finding while backpacking, I sometimes switch back to my ZebraLight H51 that has a better beam. When I need a lot of light or all night runtimes I use a ZebraLight H600 headlamp (notes on ultralight headband). My family regularly uses a Black Diamond Apollo lantern both around the house and when camping.

Issues to Consider

There are a wide variety of headlamp and flashlights. They come at all sorts of different price points, features, and characteristics. Below are some of the issues I consider when selecting a light.


The need for light varies based on how light sensitive a person’s eyes are (often older folk need more light) and the task at hand.  Given time, many people’s eyes can adjust to available light. If you are patient, you might find that the moon and stars provide enough light for a number of activity.

Petzl has been developing lights which adapt their intensity based on the conditions. While I think this is an interesting idea, everyone I know with one of these headlamps has told me that it’s still a work and progress and more gimmick than function.

I look for lights which have multiple output levels. My experience is that: 1 lumen is enough light for simple  tasks; 10-30 lumens is plenty of light for any close proximity  task and provides enough light to follow well worn trails; >70 lumens in a focused beam for basic cross country travel, and I need at least 200 lumens for moderate speed cycling or to locate markers that might be in the distance while hiking.

For up close activities, an even floody light is desirable. When moving fast (running, biking, skiing), or trying to see things in the distance, a narrower, focused beam is helpful. The distance that a light is effective is called the “throw”. Often lights will provide a compromise by having a focused center (call the hotspot), with a broader area of light at a lower intensity called the spill.


I strongly recommend using flashlights and headlamps which have full regulation, sometimes called boast regulation. Full regulation uses circutry to keep a steady amount of power flowing through the LED. As a result, the brightness of the light stays nearly flat through until the battery is really out out of power. An unregulated light just lets the current flow which means the light is quite bright with fresh batteries, but falls off quickly.

The best way to understand the performance of a light is through a runtime graph.  In the graph below you can see the performance of four different flashlights.  the Fenix has full regulation and keeps nearly 100% of it’s initial output for most of the flashlight’s runtime.  The Sapphire light has no regulation. It’s very bright for the first few minutes and then it’s brightness falls off fairly quickly. The EOS flashlight uses simple resistance regulation which limit the amount of current that is permitted to flow. This prolonging the “high” runtime by limiting the maximum brightness with new batteries.

candlepower forums,com

You should know that unregulated lights tend to report how long light is generated rather than light which is at a particular intensity. So in the case of a flashlight like the Sapphire, the runtime might be reported as 9 hours, even though it’s at 50% after just 30 minutes, and a quarter after 2 hours. This issue is explore more in the article why headlamp claims are deceptive.

Battery Type & Sizes

Historically I have selected lights it to use AA because this is what most of my other devices use, they are easy to find in stores, and have a reasonable size/power density trade-off. When I have need a light which is exceptionally bright or has a long run time I will consider 18650, 22700, or internal rechargeable batteries because USB is becoming a ubiquitous power source.

During summer months I recommend using eneloop (or other low discharge NiMH formulation) batteries which outperform classic alkaline batteries and are more eco-friendly.

In cold conditions NiHM batteries function better than alkaline, but I would recommend using Lithium batteries because they even less affected by cold, hold more power, and, are 30-40% lighter. You should be aware that lithium batteries can burn out un-regulated LEDs. Verify that your light is rated to be used with lithium batteries.

I would recommend getting a conditioning charger because you can reduce a battery’s capacity and lifecycle using a poor charger. I like the La Crosse BC1000 for AAA and AA size NiMH batteries because it just works and it’s easy to insert and remove batteries. If you need other sizes / formulations, say 18650 or Li-Ion, or are looking for the best value, the Nitecore I4 is a great choice. The tiny oLight universal magnetic charger powered by a USB port lets you charge virtually any battery. There are a number of batteries that have integrated charging circuits powered by a micro-USB ports such as the Fenix ARB-L14-1600U. Alas, even though this AA Li-Ion battery limits output to 1.5V, it doesn’t work in Zebralight brand lights. 

Other Issues to Consider

Beside what’s listed above things I look for:

  • reasonable user interface (can be used with gloves and doesn’t have many blinking modes you have to cycle through)
  • weight (lighter generally better)
  • waterproof
  • battery life indicator
  • good price / value
  • for headlamps comfort to wear and stay on the head when active
  • additional features such as being an USB power bank.

I don’t have a recent of experience with headlamps which are extremely bright (>600 lumens) or come with remote battery packs. Remote battery pack are very important when in extremely cold environments because the battery pack can stay under your coat to keep the batteries warm so their performance doesn’t fall due to the cold environment.


I recommend getting a headlamp because the hands free operation is extremely useful and you can always use it like a hand light.  Why would you use a headlamp in your hand?  Having a light source coming from the same location as your eyes creates hard shadows which can make it harder to see things. When night hiking having the light coming from down around your waist makes it much easier to see the terrain. Secondly, when in groups, there is a tendency to turn toward people who are talking which minimally exposes them to the spill of the headlamp if the headlamp is properly adjusted down, or worst case, you hit your friend with full force light. When in a group, a useful trick is to wear the headlamp loosely around your neck with the beam angled down toward your hands.

Headlamps with swappable batteries I would recommend:

  • Zebralight make numerous excellent headlamps. These are my top recommendation if their price isn’t too high. I suggest the standard (non floody) reflectors for all-around use, powered by whatever batteries has the size / runtime profile you desire. Zebralight maintains a google sheet with the specs of all their lights. I have used a ZebraLight H51 from 2010-2019 for most of my portable lighting needs. The current version of this light is the H53. The H51, an AA eneloop battery, and original headband weight 3.5oz. It has 6 regulation output levels which include lumens/runtime : 0.2/19 days, 8/39h, 30/10h, 200/55min. I have the standard (non floody) reflector: the beam has a hot spot with enough throw for wayfinding and enough spill to be useful for close up tasks. The headband is comfortable, removable, with a glow in the dark holder which makes it easy to find at night. The only thing this light is missing is a battery life indicator which exists in the later version. When stored, I unscrew the tail-cap 1/3 a twist to prevent accidentally it turning on. The older Hx2 models had one advantage over the newer ones, they can use 14500 batteries.
  • Thrunite TH20, $30 is one of the best values. Durable case, good quality regulation, nice user interface which ramps up intensity rather than going in 2 or 3 big steps. Can use any formulation of AA battery including Lithiums. Beam patterns is fairly floody.
  • Mankerlight E03H, $35 can be thought of as a budget version of the Zebralight H53.

If none of the above headlamps appeals to you, I would recommend looking at headlamps made by Fenix and Nitecore since they have good regulatory circuity and durable cases at reasonable prices. The Nitecore CU10 was an interesting design which clips to your backpack strap and is powered by an external USB power source. It was discontinued shortly after release due to manufacturing issues?

Missing from my list are many of the better known manufacturers include Petzl, Black Diamond, and Princeton Tec. I have found these companies tend to lag when it comes to embracing the more efficient LEDs, regulation and durability. If I was going to choice one of the mainstream headlamps it would likely be the Petzl Actik-Core. While the light itself isn’t regulated, the USB rechargeable core is regulated. If you find your Core out of power, you can pop it out and drop in three traditional AAA batteries. I know people who really like the Petzl e-lite but I don’t recommend it. More details below in the section “Button Lights”

While I generally prefer replaceable batteries when away from civilization, I have come to appreciate several lights which integrate rechargeable batteries into their headlamps.

  • Nitecore NU21 seems to be the closest light to the original generation NU25. 
  • Sunblesa H11 a copy of the original NU25 which is a bit cheaper via Amazon
  • Petzl Bindi: is the mainstream version of the NU25 with an ultralight headband. I think the NU20 is superior to the Bindi, but you can likely buy a Bindi in a local store.
  • Black Diamond Sprinter  is a purpose designed headlamp for urban running. Around 3.5 hours near full brightness, with a flashing tail-light so motorists can see you.
  • Fenix HM50r is a bright, long running headlamp which is great for way finding. I have no personal experience with it, but several people I know and trust it love it.

Traditional (Hand-held) Flashlights

There are numerous good options today. I would suggest you start by decided what battery size you want to use. Three factors typically effect battery selection: what batteries are being used by other devices, size/weight, and run time. I generally think flashlights which are powered by AA batteries are in the “sweet spot”, through I will consider 18650 when I want longer runtime / brightness, or AAA when small size matters.

There are a number of companies which make excellent flashlights. Generally I tend toward the flashlights made by Fenix because I have found them to be well made at a competitive price. There are a number of other companies that make excellent flashlights including NitecoreolightStreamlight, SureFire,  Thrunite, and Zebralight. My short list recommended flashlights based on value and performance:

  • Thrunite Ti3, $16, uses a single AAA battery.  Good regulation with three lighting levels 0.04 lm(115h), 12 lm(6.3h), 120lm(0.5h). I think this is the best flashlight you can stash in your pocket, purse, backpack for emergency lighting. The olight i3s eos is very similar, with the maximum output being 80 lm(50 minutes).
  • Fenix LD12, $50, uses a single AA battery. Good regulation with four light levels: 5 lm, 30 lm, 70lm, 150lms. When using a 14500 battery, the maximum light jumps from 150 to 320 lumens. I think this is one of the best all around flashlights in a compact form.
  • Zebralight SC600w, $100, using a single 18650 battery. Has 10 light levels that range from 0.2 Lm (3.5 months) to 705 Lm (2.5 hours) with the ability to put out 2300 lm briefly. Great if you need a very bright light in a modest size package.
  • Wurkkos HD15, $35 is a decent 18650 powered flashlight which can double as a USB power bank.

Button Lights

Small lights that are powered by coin/watch batteries and typically have a single LED. These lights are very small and light. People often attach them to keychains, zipper pulls, or drop them in their pockets or purses for when there might be an unexpected need for lighting.

Button lights typically have only a few hours of useful light for close proximity tasks or illuminating an easy to follow path. Most button flashlight permit momentary on/off operation by squeezing the case, and most provide a way to “lock” the light on. Many of the locking mechanisms can accidentally get locked on when carried in a pocket using up the batteries. I think the  Doug Ritter Photon made by Photonlight is the best button light made. It’s user interface is very good (easy to vary intensity and to select push-to-light mode, and the various strobes stay out of the way unless you need them). The primary down side is that the light falls off pretty quickly as indicated by the Photon Freedom’s runtime graph.

Some ultralight backpackers seem to like the Petzl e-Lite, which is a headlamp powered by two coin batteries. Like the Photon Freedom, the light intensity falls off very quickly. I think a AAA powered flashlight with good regulation is nearly as small, significantly more useful, can can be significantly cheaper or one of the tiny USB rechargable keychain lights made by Nitecore and a number of other companies.

Bicycle Lights

Bicycle headlights are sometime mounted on the handlebars and sometimes mounted on the helmet. I prefer the handlebars because I see shadows being cast by obstacles that I might otherwise miss if the light was coming from the same angle as my eyes. The one advantage of a helmet-lamp is that it can shine in any direction you turn your head, not just in the direction your bicycle is going.

I believe that headlights under 200 lumens primary use is for other people to see you. I can get by on suburban streets with a 300 lumens light, but I often experienced near misses. At the speeds I ride (>15mph), I want a light with an output of least 500 lumens, with 800-1000 being a sweet spot. I certainly appreciate brighter lights, but it’s not worth the reduction in runtime or increase in size/weight. There are a number of companies that make excellent bicycles lights. I have been very happy with the lights made by Cygolite and Light and Motion. There are a number of other good manufacturers. The website bikelightdatabase.com has pretty good coverage of all the options.

Two Fish makes several different size LockBlocks which make it easy to attach a flashlight to the handlebars of a bicycle. I have had good luck using a Zebralight SC600 and my daughter used a LockBlock with AA powered Fenix flashlight.

The Cygolite Expilion 850 is the bike headlight I used for several years. It’s bright enough that I have time to maneuver around obstacles in my path, it’s reasonably compact and the batteries are swappable for longer rides, though you have to buy them from Cygolite due to a special case. This light was recently stolen which is why I replaced it

Fenix BC21R has a good range of intensities with reasonable run times, powered by a removable 18500 battery so it’s easy to carry extra power when you need longer runtime than a single battery can provide and you can charge the battery outside the light enclosure. The enclosure will also charge the battery when powered via a micro-USB port inconveniently located on the underside of the light. You likely will need unclip the light from your bike when charging unlike some lights which place the charging port on the rear of the light which is easily accessed while sitting on the mounting. I found the “dual lens” a great theory, but found the more even light distribution from other lights such as the Cygolite 850 to be more useful.

I think it’s very important to use tail lights during the day and at night time. They make bicycles significantly more visible. There are a lot of good tail lights. I don’t have a strong preference between them. I purchased the original Cygolite HotShot several years ago, and have been very pleased with it. Recently my Hotshot was stolen. I ordered a replacement from Amazon which was defective. The forth HotSpot I received finally worked… the rest were returned because they were DOA.


I don’t have recommendations  if you want a lot of light (>800 lumens). It used to be that the best option for this sort of light was fuel powered lanterns which ran on iso butane canisters on propane. These days I am sure there are good alternatives which use LED that are significantly more durable, and likely have a better light produced / weight ratio.

If you want less than 700 lumens, there are a number of excellent LED lanterns. These lanterns are not just more durable with a better amount of light / weight compared to their fossil fuel siblings, but if you have a solar panel, you can “fuel up” during the day. My favorite options is the fairly compact Black Diamond Apollo which can put our 230 lumens and is powered by an internal rechargeable battery and can switch to three AA batteries if you need additional power. If you need more light, the UST 30 day lantern puts out 700 lumens, and is powered by three D batteries.

In the old days, candle lanterns, or small oil lamps were the lightest way to provide long lasting light. There were not bright, but you could get something like 12 hours out of a 2oz candle. The candle holder would be another 4-6oz. The old candle lantern has the one advantage of providing a bit of warmth which is nice on a cold night.

Other Information

Candle Power Forums (CPF), is one of oldest online communities devoted to flashlights. They have great reviews which typically include runtime graphs and beam shots. FlashlightWiki has links and information for people who are obsessed by all things flashlight like.

There used to be a large number of websites which specialize in high quality flashlights, headlights, and batteries. These days it seems like there are only two that are left: brightguy and battery junction.

An interest podcast about how the cost of lighting dropped through history. Until 300 years ago, a day of labor would pay for around 10 minutes of artificial light. The development of kerosene in the 1800s raised this to 5 hours. Today, a day of labor pays for more than 20,000 hours of artificial light!!

Low Cost

For basic task lighting, the photon II knock-offs can be found for between $1-$3 many places.

Leave a Reply

Your email address will not be published. Required fields are marked *