Experience with ZebraLight H51 in freezing cold

theory_w

Newly Enlightened
Joined
Mar 17, 2013
Messages
6
Just got my first ZebraLight, an H51fc. I'm really liking the design, the UI, and the "directed flood" beam. :)

5Qm0yLD.jpg


Unfortunately I'm going to have to return it due to one major issue: when the light is cold (freezing cold), the switch gets stuck in the depressed position! This makes the light endlessly cycle through the three brightness levels, and I have to take my gloves off and struggle with the switch to get it to release.

The switch works fine when it's warm, so I don't know whether this is a manufacturing defect or a design flaw. I looked for minimum operating temperature specs, but couldn't find anything. Could it be that the rubber switch cover contracts or stiffens in the cold, enough to hold down the soft-touch button?

While I wait for ZL customer service to get back to me, I thought I'd ask CPF: has anyone used an H51 in the freezing cold, and if so, how did it do?

What I really want to know is whether I should try my luck with a replacement H51, or get a refund and try something else. The H502 supposedly has a stiffer switch, so that would be my second choice.
 

reppans

Flashlight Enthusiast
Joined
Mar 25, 2007
Messages
4,873
Sounds like some moisture got inside the electronic switch and is freezing. I'd return it - even if you don't use it in the cold, the moisture might corrode the contacts. If not, try sticking it a ziplock bag with rice for week or so.
 

Bolster

Flashlight Enthusiast
Joined
Oct 7, 2007
Messages
1,542
Location
Mexifornia
Sounds like some moisture got inside the electronic switch and is freezing. I'd return it - even if you don't use it in the cold, the moisture might corrode the contacts. If not, try sticking it a ziplock bag with rice for week or so.

Clever way to dry a light. Might even speed the process by using desiccant--overnight would probably be long enough in that case. Others simply turn the light on and let it warm up to speed the drying process.
 

Shorty66

Enlightened
Joined
Nov 15, 2008
Messages
348
Location
Germany, Brunswick
I used my ZL H51 multiple times in -20°C and below and never got a problem.
I realized though, that its easy to drop the battery cap while changing atterys with gloves on. I think zebralight should attach the cap with a plastic strap or so.
 

jorn

Flashlight Enthusiast
Joined
Nov 8, 2008
Messages
2,502
Location
Norway
Used the h51fc last week. 4 days in a tent. In a awful blizzard. Could barly see 2 meters. At night freezing cold. No problems with the zebra at all, but mine is totally waterproof.
 

Julian Holtz

Enlightened
Joined
Nov 4, 2005
Messages
343
Location
Germany
Have you tried unscrewing the cap and putting it back on? Maybe the air contracts inside and pulls down the rubber thing from inside.

A frined of mine had the opposite effect on a Fenix: The expanding air inside caused the button to bulge quite noticably....
 

theory_w

Newly Enlightened
Joined
Mar 17, 2013
Messages
6
I used my ZL H51 multiple times in -20°C and below and never got a problem.
Used the h51fc last week. 4 days in a tent. In a awful blizzard. Could barly see 2 meters. At night freezing cold. No problems with the zebra at all, but mine is totally waterproof.
:twothumbs

Thanks everyone, this gives me confidence that a replacement H51 won't have the same problem. I requested an RMA, and sent the light back to Texas today.

If moisture did get inside the light, I don't know how. It never got wet, and the switch first got stuck as soon as I unboxed the light and put an Eneloop in it. It was still cold from sitting in the mailbox! :p

One of the tests I did was to take the light outside without the tailcap on, and the switch still got stuck, so that should rule out negative air pressure (unless the battery tube is sealed off from the head?).

I'll report back once I get the replacement and try it out.

UPDATE: The replacement light works just fine in the cold. :D Although winter was almost over by the time I got the new light, there were still a few frigid nights when I was able to test the switch. No more sticking.

Clever way to dry a light. Might even speed the process by using desiccant
That reminds me, my NiteCore EA4 came with one of those "DO NOT EAT" packets inside the battery tube, and the Zebra didn't. I don't know if it makes any difference in a sealed flashlight, but it couldn't hurt, right?
 
Last edited:

Lurveleven

Flashlight Enthusiast
Joined
Dec 21, 2004
Messages
1,237
Location
Bergen, Norway
I don't find any Zebralight headlamp good for really cold use. It impossible to use them with gloves.
Regarding the H502 switch, mine is not very stiff, about the same feel as on my SC51. The switch on the H600 on the other hand is very stiff, I wonder if the designer have tried to push it while he had it on his head? It just pushes the lamp instead of clicking the switch :shakehead I must say I'm not very impressed by the design of the Zebralight headlamps, they have missed on the most important part, the user interface.
 

theory_w

Newly Enlightened
Joined
Mar 17, 2013
Messages
6
Finally got my replacement H51fc, and while I haven't tested it in the cold yet, I wanted to note that there is a sealant between the battery tube and the head.

jrTgdZy.jpg


See the gray goop? It looks like the head should be fully sealed, even with the tailcap removed. :)
 

rojos

Enlightened
Joined
Jul 18, 2012
Messages
211
See the gray goop? It looks like the head should be fully sealed, even with the tailcap removed. :)

The pin-hole sized via's in the circuit board probably go through, so I don't think anyone should be dunk testing these with the tailcap off any time soon. :)
 

Patriot

Flashaholic
Joined
Feb 13, 2007
Messages
11,214
Location
Arizona
I don't find any Zebralight headlamp good for really cold use. It impossible to use them with gloves.
Regarding the H502 switch, mine is not very stiff, about the same feel as on my SC51. The switch on the H600 on the other hand is very stiff, I wonder if the designer have tried to push it while he had it on his head? It just pushes the lamp instead of clicking the switch

Interesting. I had to got put a H600 on my head and switch it on to relate to this. Rather than pit the friction of the rubber holder and elastic against the pressure of the switch, perhaps hold the head between your thumb and middle finger while the index finger depresses the switch. Intuitively, I've always supported any headlamp with other fingers while I switch them on, from old school PTec twisties to cheap Rock Rivers. None of the one's I can think of or own have a switch so soft that I can activate with one finger and expect them not to shift on my head. Kinda seems like asking a lot....haha. :)

Another thing I've caught myself doing when the switch end is over my left eye but only my right hand is free, or visa versa, is pinching the light lengthwise between my thumb on the tail and index finger on switch. Lastly, one could always (if both hands are free) push on the tail of the light with one hand while the switch is depressed with the other hand with apposing force. Sometimes this works even when I have something in my hand but I can use the back of my hand or knuckle to support the tail.

The switch of course, is scaled to the size of the light. It's wedged in close behind the reflector. I suppose that they could have made the switch larger, to make it more glove friendly, but either the light would have to be larger or the switch more exposed. The 1st gen Zebra's had a switch like that and they were accidentally activated all the time. I still have to unscrew the tail cap on my H30 and original H50 or it has a dead battery every time.



Theory w, Thanks for telling us about this issue. It's the first cold weather type of failure that I've heard of with this type.
 

Lurveleven

Flashlight Enthusiast
Joined
Dec 21, 2004
Messages
1,237
Location
Bergen, Norway
I think I have been spoiled with the Stenlight, it is the most glove friendly headlamp I know of, and has the best UI. Too bad it has its battery on the back or in a pocket. With the Zebras I need to take the glove off and support with other fingers when switching. I think the Zebralights would be better if the switch sat on the side instead of the end, so you could just support with your thumb and press with you index finger.
 

markr6

Flashaholic
Joined
Jul 16, 2012
Messages
9,262
I think I have been spoiled with the Stenlight, it is the most glove friendly headlamp I know of, and has the best UI. Too bad it has its battery on the back or in a pocket. With the Zebras I need to take the glove off and support with other fingers when switching. I think the Zebralights would be better if the switch sat on the side instead of the end, so you could just support with your thumb and press with you index finger.

I wonder if there are variations in the switches. Because with my H51 and H51w, I can literally just tap the switch with my pinky finger to change modes without supporting the lamp. Actually, I can even use the pressure from the glove before my actual finger makes contact inside the glove (does that make sense)? After being used to this, I was shocked to see how difficult the H600w was. Yes it prevents accidental activation, but I think a balance somewhere between the H600 and H51 would have been more appropriate since it's already well recessed.
 

Knight_Light

Enlightened
Joined
Mar 2, 2013
Messages
648
I used my ZL H51 multiple times in -20°C and below and never got a problem.
I realized though, that its easy to drop the battery cap while changing atterys with gloves on. I think zebralight should attach the cap with a plastic strap or so.
I totally get where you are coming from with this having been in conditions similar to those. But I think the majority of the people don't use this light in these types of circumstances and would probably complain about that feature as a nuisance. Think of the EDC market.
 

Knight_Light

Enlightened
Joined
Mar 2, 2013
Messages
648
A frined of mine had the opposite effect on a Fenix: The expanding air inside caused the button to bulge quite noticably....
Same thing happened to me on more then one occasion when running the Quark AA2 on high mode. When you are unaware of this phenomenon it can be somewhat startling when the flashlight is standing on its tail and then all of a sudden falls over. :eek:oo:
 

DIΩDΣ

Enlightened
Joined
Aug 24, 2011
Messages
262
Location
Ohio
I think I have been spoiled with the Stenlight, it is the most glove friendly headlamp I know of, and has the best UI. Too bad it has its battery on the back or in a pocket. With the Zebras I need to take the glove off and support with other fingers when switching. I think the Zebralights would be better if the switch sat on the side instead of the end, so you could just support with your thumb and press with you index finger.

I don't follow your issue. I do just as you said you wish you could do with zebras... I just use my thumb and middle finger to switch my H51, with gloves on too. Just squeeze it - thumb on the battery cap end and finger on the button. Sure with gloves I am little clumsier and getting the timing right double clicking and stuff, so I usually just do the hold down until it starts switching modes and release when its on the one I want. I love the UI and format... only possible thing I would say isnt ideal is some of the 'timing' requirements of the UI, but luckily there is multiple ways to cycle through.
 

Patriot

Flashaholic
Joined
Feb 13, 2007
Messages
11,214
Location
Arizona
DIΩDΣ;4175653 said:
I don't follow your issue. I do just as you said you wish you could do with zebras... I just use my thumb and middle finger to switch my H51, with gloves on too. Just squeeze it - thumb on the battery cap end and finger on the button. Sure with gloves I am little clumsier and getting the timing right double clicking and stuff, so I usually just do the hold down until it starts switching modes and release when its on the one I want..

+1

Since I live in Arizona, I don't use much in the way of gloves except during a few cold winter days at higher elevations. I was curious so I went and used the H600 with three different gloves, the last pair being a Gortex shell over 200g of thinsulate. I was still able to use the switch pretty effectively although obviously, not quite as efficiently. It was good to know that it's possible though.
 

jorn

Flashlight Enthusiast
Joined
Nov 8, 2008
Messages
2,502
Location
Norway
DIΩDΣ;4175653 said:
I don't follow your issue. I do just as you said you wish you could do with zebras... I just use my thumb and middle finger to switch my H51, with gloves on too. Just squeeze it - thumb on the battery cap end and finger on the button. Sure with gloves I am little clumsier and getting the timing right double clicking and stuff, so I usually just do the hold down until it starts switching modes and release when its on the one I want. I love the UI and format... only possible thing I would say isnt ideal is some of the 'timing' requirements of the UI, but luckily there is multiple ways to cycle through.

+1
No problems with gloves. Use the press and hold ui, and it will cycle to the mode I want. Usually dont use the double click etc with gloves on.
 

Lurveleven

Flashlight Enthusiast
Joined
Dec 21, 2004
Messages
1,237
Location
Bergen, Norway
I did some more testing and found a lighter pair of gloves, and then it was no problem using them, but with the thick gloves the H600 is very difficult while the H502 is considerably easier than the H600. And with these mitts I really struggle.
 
Top