The Official Zebralight Thread .

They do, however I've never used them on high output, only medium. 18650 Zebras require a higher amp draw that two CR123 (3.5amps each) can't provide. So to be safe, I've only used medium levels.

Will using high output with two CR123s be safe? I'm not sure
 
Do two CR123a work in an 18650 Zebra?

I see the voltage range is specified as 2.7V to 6V. But a pair of new CR123a would total 6.4V…

I ask because Im debating buying a Zebra for a backcountry skiing emergency kit. I could choose an AA model, but not sure if that would be the best option in terms of output and runtime.

Im considering an 18650 model but LiIon can have performance issues when frozen. So Im wondering if a matched pair of CR123a would make a good backup battery option.

Also, for anyone that may have experience skiing in the dark, would you pick the Floody lens, or the clear lens? Im leaning towards floody, but have no outdoor Zebra beam experience.

Suggestions welcome ;-)
i love my zebra not sure if it can run 2 cr123s but id love to know
 
Also, for anyone that may have experience skiing in the dark, would you pick the Floody lens, or the clear lens? Im leaning towards floody, but have no outdoor Zebra beam experience.

Suggestions welcome ;-)
Sounds fun! Aside from well lit runs accessed by lifts, I have not tried skiing in the dark. However, I've done a lot of nighttime outdoor and back country travel, including in the snowl at night.

For an emergency kit that may or may not get used? I'd probably just go with a floody AA Zebralight headlamp, but really any small lightweight headlamp will do the job in a pinch so long as you're not booking it! I would however advise coming up with a way to mount it lower than your face for when moving. Beyond casting shaddows better than having it on your head, low temps come with heavily condensing breath that obsures vision when hit directly by a light on your forehead. Falling snow does the same. Still, bright headlamps have long been the standard for winter mountaineering.

I've never had a ZL fail using a Li-Iion rechargeable or lithium battery down into the teens F°. The thing that I know will kill a lithium ion battery (18650 or other) is discharging it while it's very cold, like running your phone or charging something with a battery pack. They seem to hold their capacity well at low tems so long as they're not being discharged at very low temps.

I'd immagine any significant use of a flashlight also heats the cell enough to mitigate the problem of low temp discharge drain, but I've little experience witth many hours of use in temps below the 20s F. I do know that many serious winter mountaineers prefer lithium and Li-ions over Ni-MH, and never use alkalines. Something with a high discharge rating also tends to be prioritized for extreme cold. Many prefer and will use off-lamp batteries that they'll keep in their pockets, attatched to headlamps with a chord. But this doesn't seem to be a big concern unless it's exceptionally cold. Here's an old BPL discussion you may find helpful.

Beyond an emergency light, if I know that I'll be doing a lot of night travel my preferred system has long been two lights. The first being a flood, positioned, mounted, or held in low position. The second being something more spotty as a head lamp or hand held. The faster the speed of travel, the higher the light output I will use, requiring a more robust light.
 
I've never had a ZL fail using a Li-Iion rechargeable or lithium battery down into the teens F°.
...
The faster the speed of travel, the higher the light output I will use, requiring a more robust light.
thank you for your thoughts

so, lets say max speed is 20mph, max distance is 20yards, and low temp is 5F (plus windchill), about how many lumens do you think that calls for and which of these two lights would you choose?:

H54Fc N:
Light Output (runtimes)
  • High: H1 238Lm ( 1.3 hr) or H2 197Lm ( 1.7 hr) / 155Lm ( 2.1hrs) / 102Lm ( 3.5hrs)
  • Medium: M1 55Lm ( 6.5hrs) or M2 15Lm (30.6 hrs) / 8.1Lm (2.8 days) / 2.9Lm (6.8 days)

H600Fc
Light Output (runtimes)
  • High: H1 1568 Lm (PID, 2.5 hrs) or H2 980 Lm (PID, 2.9 hrs)/562 Lm (PID, 3.1 hrs)/296 Lm (5.3 hrs)
  • Medium: M1 143 Lm (12.5 hrs) or M2 63 Lm (27.5 hrs)/25.7 Lm (2.7 days)/9.6 Lm (7.1 days)
 
thank you for your thoughts

so, lets say max speed is 20mph, max distance is 20yards, and low temp is 5F (plus windchill), about how many lumens do you think that calls for and which of these two lights would you choose?:

H54Fc N:
Light Output (runtimes)
  • High: H1 238Lm ( 1.3 hr) or H2 197Lm ( 1.7 hr) / 155Lm ( 2.1hrs) / 102Lm ( 3.5hrs)
  • Medium: M1 55Lm ( 6.5hrs) or M2 15Lm (30.6 hrs) / 8.1Lm (2.8 days) / 2.9Lm (6.8 days)

H600Fc
Light Output (runtimes)
  • High: H1 1568 Lm (PID, 2.5 hrs) or H2 980 Lm (PID, 2.9 hrs)/562 Lm (PID, 3.1 hrs)/296 Lm (5.3 hrs)
  • Medium: M1 143 Lm (12.5 hrs) or M2 63 Lm (27.5 hrs)/25.7 Lm (2.7 days)/9.6 Lm (7.1 days)
That's moving very quickly through the cold, cold night! Don't go Sonny Bono!

Given those options/scenario, for use as a primary? I'd go with the H600Fc as a headlamp, making sure the 18650 is overkill on the discharge rating to account for cold…maybe 20A…..and bring extra 18650 batteries. The cold will affect performance, but shouldn't catastrophically. Probably warm the light close to your body before turning it on, and refrain from using it on the H1 or H2 settings. I'd also make sure the headband can fit around you waist when fully opened, just in case your run into visibility issues on account of breath condensing or snow falling.

I'd bring the H54Fc N as a backup with a few energizer lithiums….Do not rely on Ni-Mh or alkaline cells at those temps. If you need to use it, slow down. Also refrain from the H1 and H2 settings. Same wide headband thing for the waist.

Ideally though at those temps and speeds (20mph at night is very fast), I'd probably opt for something with an external battery pack and just be bright as hell. Maybe looking at the the serious mountain bike light market. Again, I've limited experience below 20°F.

To put things in perspective,

20mph in rough terrain at night more or less maps onto aggressively riding a mountain/cross bike on fire roads. Here's what I use (non sub freezing temps).
  • An Emissar DW4 Mule on my front fork, keep it at 500ish lumens.
  • A Zebralight H600c Mk4 (Spot) mounted on my helmet, set to 500 ish lumens.
This provides plenty of light to ride aggressively, safely. It's way more than I would ever use for hiking or running, even in cross country terrain off a trail.

Though you would loose that two lights provide (flood on the immediate ground and spot for further out), I believe the H600Fc would be enough, though not ideal mainly on account of the speed you cite.

Last thing to note. I find myself needing the most lumens at dusk/dawn when it's not totally dark. Once it gets dark, less light is needed. Counter intuitive, but true.

Another couple of links you may find helpful, considering your use case:
 
thank you for your thoughts

so, lets say max speed is 20mph, max distance is 20yards, and low temp is 5F (plus windchill), about how many lumens do you think that calls for and which of these two lights would you choose?:

H54Fc N:
Light Output (runtimes)
  • High: H1 238Lm ( 1.3 hr) or H2 197Lm ( 1.7 hr) / 155Lm ( 2.1hrs) / 102Lm ( 3.5hrs)
  • Medium: M1 55Lm ( 6.5hrs) or M2 15Lm (30.6 hrs) / 8.1Lm (2.8 days) / 2.9Lm (6.8 days)

H600Fc
Light Output (runtimes)
  • High: H1 1568 Lm (PID, 2.5 hrs) or H2 980 Lm (PID, 2.9 hrs)/562 Lm (PID, 3.1 hrs)/296 Lm (5.3 hrs)
  • Medium: M1 143 Lm (12.5 hrs) or M2 63 Lm (27.5 hrs)/25.7 Lm (2.7 days)/9.6 Lm (7.1 days)
The good news is that windchill doesn't affect inanimate objects (it only chills use because we sweat). So, absolute temperature is all that matters.

Anything above freezing is actually pretty much "business as usual." Things don't get weird until you're in sub-zero Fahrenheit. I've always had great luck with Eneloops in the cold (they work as normal until -4F, but I've found they seem to "warm up" with use, so if you store a light in your jacket, turn it on, it seems to be just fine once it's on). Some people like headlamps with an external power supply, as you can keep that under a hat and/or in a jacket.

Also, while I haven't done nighttime skiing, I do bicycle at night. I think my gearing maxes me out at ~35mph. I wouldn't use a floody light on my head at those speeds. I also do assorted outdoor winter adventuring, so I think I can put both experiences together with some suggestions, haha.

While I normally find the beam pattern useless and awful, the Acebeam H16 actually has a pretty good beam for moving at a clip at night; it's mostly just a very large, round hotspot. I only hung onto it to use as my night cycling headlamp. It's kind of trash with the 14500, but it's stable at the under 100 lumen outputs with an Eneloop.
With the 6500K variant, he got almost 8 hours of 50 lumens with an Eneloop pro (so, 6 hours with a white Eneloop?):

I wouldn't second the comment about not having one on top your head, but I'd add some nuance to say you're going to want two lights.

On my bike, I find a forward facing light is very helpful, but having one on your head is also almost mandatory, because you NEED to immediately have light facing where you look (thus, needing throw over flood on your head). If a hazard suddenly appears AT SPEED, you NEED the ability to see whatever you quickly look at. That's why I like a throwier headlamp. BUT, snow is reflective, so even a little light (even floody) goes a LONG way. Snow really changes the nature of floody lights. They "seem" to throw better, and you just kind of see...everything. They still don't throw, but it's interesting that the reflective nature of snow seems to make them feel floodier (and a hotspot kind of gets blinding in snow).

BUT, I do think a floody light clipped to your pocket or belt is VERY helpful, as it will have cast an even light closer to foot level, which will REALLY help with seeing changes in elevation across the ground (a single, high angle light tends to wash out shadows, and you'll crunch into a dip or hop on a bump, or...trip).

The other good news is that snow is HIGHLY REFLECTIVE, and if there is ANY moonlight, it's going to be shockingly bright out. Depending on the phase of the moon, you might not even need a light. For anything close up in the snow, I pretty much run a headlamp at super low. Honestly, if it's like a full (or near full) moon, you might find a red headlamp to be great, as it will add SOME visibility, but mostly maintain your low light vision. Once you really adapt to that lower light level on a snowy, moonlit night, it's very pleasant.

If there's no other light around, I often run the Acebeam H16 at 30 or 100 (max) lumens on my head, with my bike mounted light also on low. Twilight and around other light sources, you'll need to maybe bump it up - but, again, snow is very reflective.

Also, another not bad idea for a headlamp (I think I remember you saying you have an H150) is to wear two, one by each ear. With the H150, you can remove the top strap, and turn the light in the holder, and it's a surprisingly awesome setup, haha. Or, run one at a time, so as the battery power goes down, you can swap to another...Heck, they're small and light enough, you could probably wear three at once, hahah.

Also, a warm CCT is nice in the snow. It tends to not be as blinding if it starts snowing, and it's MUCH softer on the eyes, since the highly reflective snow will beat your eyes up if you're running anything over 5000K.
 
I wouldn't second the comment about not having one on top your head, but I'd add some nuance to say you're going to want two lights.

On my bike, I find a forward facing light is very helpful, but having one on your head is also almost mandatory, because you NEED to immediately have light facing where you look (thus, needing throw over flood on your head). If a hazard suddenly appears AT SPEED, you NEED the ability to see whatever you quickly look at. That's why I like a throwier headlamp. BUT, snow is reflective, so even a little light (even floody) goes a LONG way. Snow really changes the nature of floody lights. They "seem" to throw better, and you just kind of see...everything. They still don't throw, but it's interesting that the reflective nature of snow seems to make them feel floodier (and a hotspot kind of gets blinding in snow).

BUT, I do think a floody light clipped to your pocket or belt is VERY helpful, as it will have cast an even light closer to foot level, which will REALLY help with seeing changes in elevation across the ground (a single, high angle light tends to wash out shadows, and you'll crunch into a dip or hop on a bump, or...trip).

The other good news is that snow is HIGHLY REFLECTIVE, and if there is ANY moonlight, it's going to be shockingly bright out. Depending on the phase of the moon, you might not even need a light. For anything close up in the snow, I pretty much run a headlamp at super low. Honestly, if it's like a full (or near full) moon, you might find a red headlamp to be great, as it will add SOME visibility, but mostly maintain your low light vision. Once you really adapt to that lower light level on a snowy, moonlit night, it's very pleasant.
To clarify, if using only one light, I agree it should not be put around the waist if moving 20mph! That would be a horrible idea!

Only situation where I'd have only one light and put it around the waist is if I were moving very slow (2/3mph) or if breath vapor/snow is impending visibly due to a headlamp shining directly from eye view. And in the latter case, slowing way down would be an imperative.

At 20mph in the dark, I agree that something spotty, head mounted, is pretty much requisite.

As for a waist mounted light, I keep a silicone holster attached to most backpack waist belt straps. Throw an AA mule on it when walking for a long time. Works great!
waist mule.jpg
 
To clarify, if using only one light, I agree it should not be put around the waist if moving 20mph! That would be a horrible idea!

Only situation where I'd have only one light and put it around the waist is if I were moving very slow (2/3mph) or if breath vapor/snow is impending visibly due to a headlamp shining directly from eye view. And in the latter case, slowing way down would be an imperative.

At 20mph in the dark, I agree that something spotty, head mounted, is pretty much requisite.

As for a waist mounted light, I keep a silicone holster attached to most backpack waist belt straps. Throw an AA mule on it when walking for a long time. Works great!View attachment 73199
100% agreed on all counts.

Clipping a headlamp on a belt or belt loop can also work really well if you're not wearing a back. I've even had decent luck with using a shirt pocket.
 
Another couple of links you may find helpful, considering your use case
Thank You!, takeaway regarding Operating Temperatures:
  • Disposable Eveready lithiums (available in AAA, AA, CR123A) are the most-cold tolerant but expensive. ~ 75% rated capacity at -4°F
  • Li-Ion are the next best for cold, 50% rated capacity at -4°F
  • NiMH are not good in cold, ~ 20% rated capacity at -4°F
  • Alkalines aren't recommended below 32°F
a hotspot kind of gets blinding in snow...
I've always had great luck with Eneloops in the cold (they work as normal until -4F
thanks for your input, it supports my bias.. lol
I lean towards floody beams lately, and I like Eneloops, they seem to tolerate my car summer temperatures better than LiIon.. while also seeming to work equally well in winter where more typical temps are above 10°F..

Except this week temps at the Ski Area Touched -1°F, and yes 20mph is a "not very fast" speed, on the open groomers during the day, not in the trees, and not at night. ;-)

After spending some time debating an H54Fc N vs an H600Fc Mk 1V, I ended up grabbing a used H53Fc N..

It was interesting to me, to learn that LiIon retains capacity in Negative F Cold, better than NiMh

Youre memory is correct, I do have a Skilhunt H150 that lives in my car, loaded w Eneloop with Ultimate Lithium backups. I did not want to use it in a backpack with a compass, due to the magnets, one in the tail, and one for the magnetic charging port, that is not removable.

I may still end up also buying an H600.. depending how my testing of the H53 pans out, it may become a gift to a good friend who likes to ski on the full moon (without any flashlight) and is only interested in lights that can use AA primaries.

This is a photo he took on one of his Full Moon descents:
thumbnail.jpg

That is the same terrain Im building the emergency kit for, but I dont plan to be there at night, that would only happen if I got stranded, during one of my daytime descents..

buying for imaginary scenarios, drives my consumer impulses ;-)
 
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Do two CR123a work in an 18650 Zebra?

I see the voltage range is specified as 2.7V to 6V. But a pair of new CR123a would total 6.4V…

I ask because Im debating buying a Zebra for a backcountry skiing emergency kit. I could choose an AA model, but not sure if that would be the best option in terms of output and runtime.

Im considering an 18650 model but LiIon can have performance issues when frozen. So Im wondering if a matched pair of CR123a would make a good backup battery option.

Also, for anyone that may have experience skiing in the dark, would you pick the Floody lens, or the clear lens? Im leaning towards floody, but have no outdoor Zebra beam experience.

Suggestions welcome ;-)
No. They won't even fit, let alone run safely.
 
Thank You!, takeaway regarding Operating Temperatures:
  • Disposable Eveready lithiums (available in AAA, AA, CR123A) are the most-cold tolerant but expensive. ~ 75% rated capacity at -4°F
  • Li-Ion are the next best for cold, 50% rated capacity at -4°F
  • NiMH are not good in cold, ~ 20% rated capacity at -4°F
  • Alkalines aren't recommended below 32°F

thanks for your input, it supports my bias.. lol
I lean towards floody beams lately, and I like Eneloops, they seem to tolerate my car summer temperatures better than LiIon.. while also seeming to work equally well in winter where more typical temps are above 10°F..

Except this week temps at the Ski Area Touched -1°F, and yes 20mph is a "not very fast" speed, on the open groomers during the day, not in the trees, and not at night. ;-)

After spending some time debating an H54Fc N vs an H600Fc Mk 1V, I ended up grabbing a used H53Fc N..

It was interesting to me, to learn that LiIon retains capacity in Negative F Cold, better than NiMh

Youre memory is correct, I do have a Skilhunt H150 that lives in my car, loaded w Eneloop with Ultimate Lithium backups. I did not want to use it in a backpack with a compass, due to the magnets, one in the tail, and one for the magnetic charging port, that is not removable.

I may still end up also buying an H600.. depending how my testing of the H53 pans out, it may become a gift to a good friend who likes to ski on the full moon (without any flashlight) and is only interested in lights that can use AA primaries.

This is a photo he took on one of his Full Moon descents:
View attachment 73201
That is the same terrain Im building the emergency kit for, but I dont plan to be there at night, that would only happen if I got stranded, during one of my daytime descents..

buying for imaginary scenarios, drives my consumer impulses ;-)
Winter is beautiful. Second best season.

Also, don't let the stats mislead you on Eneloops in the cold. If you REALLY poke around online, you'll find they do pretty well (which is the general consensus of experience for a lot of us who've used them in the cold).
Generally, people will freeze cells, then measure the voltage, and or take a quick reading under load. That's where you'll see that NiMH "performs poorly," but if you look past that, you'll see occasionally people who were curious or ignorant, and kept the light on. NiMH seem to "warm up" to operating temperature pretty quickly, and then seem to work just fine, or with a still reasonable capacity.

I do some wintertime things that might have me spending 3-4 hours at a time outside, even at night (I live in the Midwest, in plant zone 5, so it gets pretty cold. We're subzero the right now, haha), and it's always been shocking how well they've worked.

If you get a chance to try it out before you're on the slopes, see how it goes in the light you want to use. You might be pleasantly surprised. I'm sure the exact light it is matters to some degree (I could see an aluminum body either working much better or much worse), how you wear it (some can be tucked under a hat), and what you're doing (even when it's REALLY cold, if I'm doing vigorous activity, I'm often stripping down to just my wool pants and my wool baselayer up top, so my body can be absolutely dumping a ton of heat out).

I'd been using AA/AAA headlamps in very cold temps for hours before I really knew what I was doing, and it always went well with eneloops, haha. That was with some like Black Diamond and/or Streamlight AAA things. Pretty much, so long as it's been relatively safe to be outside, I've successfully used Eneloops. I think things really go bad for them in the like -20*F territory, but that's not really super safe to be outside in, anyway, for more than a few mintues before frost bite hits.
 
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don't let the stats mislead you on Eneloops in the cold. If you REALLY poke around online, you'll find they do pretty well
thank you very much, I value your first hand experience..

The ski pack could be stored in the car for days, so the batteries will definitely start out below freezing.. I would put Eneloop in the light, but also bring Ultimate Lithium (Primaries). Or for an 18650 light, backup batteries would be CR123a (Lithium Primaries).

its just an emergency kit (excuse to buy a new light). I dont actually intend to ski at night, myself. I did buy an H53Fc N yesterday.. have not received it yet.

this is the terrain during the day, last season. Im in front ;-)
 
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thank you very much, I value your first hand experience..

The ski pack could be stored in the car for days, so the batteries will definitely start out below freezing.. I would put Eneloop in the light, but also bring Ultimate Lithium (Primaries). Or for an 18650 light, backup batteries would be CR123a (Lithium Primaries).

its just an emergency kit (excuse to buy a new light). I dont actually intend to ski at night, myself. I did buy an H53Fc N yesterday.. have not received it yet.

this is the terrain during the day, last season. Im in front ;-)
Oh, yeah, if it's just an emergency light, the $3 for a lithium primary is probably a great way to go.

I have this great 8-cell case made by Malamute (though, it looks like they went out of business for 2025), and I just keep that in my jacket pocket, so I have 8 fresh, warm cells as I need, haha.


The skiing looks neat. I assume somewhere out West (pines)?
Much like with cycling, I'm a bit of a masochist outlier, in that I'm not as into downhill as I am climbing and cross country. I always wanted to do cross-country skiing, but we're not getting as much snow around me as we did when I was a kid...now that I can afford the equipment, we only get snow for a couple of days before it melts, it seems :/

Of course, just to twist the knife further, while we DON'T get the snow, we DO get the arctic cold, hahahha. Kidding aside, apparently, it's from a weakened jet stream (less of a delta between the arctic and great plains means less strong wind), so we just get this constant cycling between extreme heat and cold the last few years, so even when we get snow, the next week it's so warm it melts, then it's sub-zero the next.

I'm not really complaining, though, I moved back to the Midwest because I missed our schizo weather, haha. A little more snow wouldn't hurt, though, haha.
 
The skiing looks neat. I assume somewhere out West (pines)?
Yes, 11,000 feet altitude, Ski Santa Fe, New Mexico.. its 4F up there today.. Im staying home ...

its been a terribly dry winter, similar to your experience, arctic cold, and the little snow we have had, is followed by many sunny days.. Global "Warning" ;-)
 
Yes, 11,000 feet altitude, Ski Santa Fe, New Mexico.. its 4F up there today.. Im staying home ...

its been a terribly dry winter, similar to your experience, arctic cold, and the little snow we have had, is followed by many sunny days.. Global "Warning" ;-)
Just checked a map...I didn't realize this arctic air pretty much has encompassed the entire continental U.S.

I didn't go outside much today, either.

Instead, I dug out this Olight headband I bought for $2, and swapped my H53FcN into it. So far, I think I like this setup better. It's easier to turn, but MAYBE too easy. So far, though, this seems like a great $2 upgrade to the ZL headband.
 
i just wanna see the local weather report but this trump thing is going on all day they should pause for local news they say we are geting a first time ever storm here i wanna know if its still comeing and what to expect
 
a great $2 upgrade to the ZL headband.
For my AA lights, Im a fan of the Skilhunt HB4 Small headband. It uses a clamp instead of a pair of loops (the jaws are tighter than necessary, I sand them a little):

this is my Emisar D2, uses 14500 LiIon..
lvQNGm4.jpeg

I use the same headband for my AA/14500 Skilhunt H150, and when my AA only Zebra H53Fc N arrives, it might go in a Skilhunt headband also
 
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For my AA lights, Im a fan of the Skilhunt HB4 Small headband. It uses a clamp instead of a pair of loops (the jaws are tighter than necessary, I sand them a little):

this is my Emisar D2, uses 14500 LiIon..
View attachment 73246
I use the same headband for my AA/14500 Skilhunt H150, and when my AA only Zebra H53Fc N arrives, it might go in a Skilhunt headband also
I do think the Skilhunt headband is, by far, the best, but the little pull tab system on the Olight one means it works for all kinds of lights.

I may or may not have slapped a Malkoff MDC AA in it, and had it on the side of my head. I picked them up on a sale for half price:

I got it with one of those little AAA lights. I think Olight is overpriced and has the ugliest beams (worse than Nitecore for their ugly beams), but I do think this headband is a winner, especially for how insanely cheap it is.
 
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