# Zebralight H51 - No Difference Between H1 and H2



## champ.49er (Jan 13, 2012)

I just got my Zebralight H51 and was able to program it right away. However, I noticed that there is no difference between H1 and H2. I'm using regular alkaline batteries and have tried several different alkanlines, but still not difference. I feel like my H1 is running at 100 lumens which is the same as my H2 setting and not the advertised 200 lumens. I've got an old Fenix LD10 and the H51 doesn't seem much brighter than the LD10, so I'm wondering if I got a defective light. I have so many AA batteries that I stocked up on that I had no plans to be eneloops. Are eneloops the solution or do I have a defective H51? Thanks in advance.


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## Glock27 (Jan 13, 2012)

I don't think an alkaline can provide the current for 200 lumens. You need some good NiMH and a good charger.

G27


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## finn (Jan 13, 2012)

Some alkalines have enough juice to do H1 early on in life. Expecting 200lm out of a AA alkaline is pushing electrical limits. Have you used H2 outside? I use L1,L2 and H2 by default for hiking/running/biking.

A bad kirkland AA killed my h51, so I'm looking for non-alkaline options, myself.


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## gcbryan (Jan 13, 2012)

It's probably just the batteries you are using as mentioned but even using Eneloops to my eyes there's not a huge difference.

When the battery is recently charged you can tell the difference but as soon as the charge goes down a bit not having H2 is the first sign.

If I look toward the headlamp and use H2 on a newly charged battery it is brighter but you really have to move it increaments of 3x with lights in my opinion to see more noticeable differences.

The only time I can really notice the difference is in a small narrow room. I never use H2 because the difference in output isn't worth the shortened runtime.

I think they can take a lithium primary (check first as I haven't done it). If you put one of those in and you use see some difference. I doubt that you unit is defective.


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## champ.49er (Jan 13, 2012)

finn said:


> Some alkalines have enough juice to do H1 early on in life. Expecting 200lm out of a AA alkaline is pushing electrical limits. Have you used H2 outside? I use L1,L2 and H2 by default for hiking/running/biking. A bad kirkland AA killed my h51, so I'm looking for non-alkaline options, myself.


 Yes, I used H2 outside, but wasn't too impressed compared to my LD10. When programming H2, there's no difference either between the H2 settings, so I just set it to the strobe.


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## champ.49er (Jan 13, 2012)

gcbryan said:


> It's probably just the batteries you are using as mentioned but even using Eneloops to my eyes there's not a huge difference. When the battery is recently charged you can tell the difference but as soon as the charge goes down a bit not having H2 is the first sign. If I look toward the headlamp and use H2 on a newly charged battery it is brighter but you really have to move it increaments of 3x with lights in my opinion to see more noticeable differences. The only time I can really notice the difference is in a small narrow room. I never use H2 because the difference in output isn't worth the shortened runtime. I think they can take a lithium primary (check first as I haven't done it). If you put one of those in and you use see some difference. I doubt that you unit is defective.


 Thanks for your response. Your experience with the H51 and Eneloop is very helpful. I just feel like I spent too much money for a light that I'm not taking fully advantage of. Even if I spent an extra $20 for a set of Eneloops, I feel like I won't see the full potential of H1.


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## Lite_me (Jan 13, 2012)

champ.49er said:


> *Are eneloops the solution* or do I have a defective H51? Thanks in advance.


Yes, Eneloops are the solution. As others have stated, alkaline can not provide the necessary current needed for the H1 setting on the Zebra, and will drain quickly at that setting. And, considering the dangers of batt leakage, it's best to only use alkaline batteries in an emergency.


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## Outdoorsman5 (Jan 13, 2012)

champ.49er said:


> ...I feel like I won't see the full potential of H1.



You will absolutely achieve the full potential of L1 with the right battery. Lithium primaries will work - like the Energizer Ultimate Lithium L91 batteries (in the blue pack.) NiMH batteries like eneloop are my favorite since they are rechargeable, perform perfectly in high powered devices, and are better than alkaline batteries on almost every level. Plus, neither the eneloop nor a lithium battery will ever leak & destroy your lights.


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## Arleyg (Jan 13, 2012)

Hi everyone,

I am a NOOB to this forum and this is my first post, so excuse me if I mess it up. I really got an eye full with all the great information and knowledge on this forum. 

I came across this forum while researching for some new headlamps, 

I decided the 51 series would work well for us as we have been using the cheapy energizer headlamps, and a few other unknown brand really cheap ones, and then the frustration with one that a battery leaked in, and it was not dependable after that.

So, I ordered a 51 & 51w. They are totally awesome lights.

I gave my other half the 51w, so that way she wouldn't blind the chickens at night when we collect their eggs.

I really like them both, and it appears they will really help at night as we are running around doing our chores.

I also bought some eneloops as suggested from different members on this forum. I normally always use Kirkland brand, but was wondering how much more output the eneloops give.

Thanks again,

Arleyg


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## RedForest UK (Jan 14, 2012)

As I'm from the UK I'm not familiar with the Kirkland brand, but I was under the impression they were disposable 'alkaline' batteries. On the low/med modes there will be little difference in output or runtime, as the light is regulated to maintain the same output from whatever battery. On the high and max modes however the eneloops should give runtime up to 5x as long as the alkalines which just give up at such high currents, the output will therefore also be higher on eneloops as the alkaline cells simply can't provide enough current for more than a few seconds.

Also, you won't ever have a leaking problem with eneloops.


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## champ.49er (Jan 14, 2012)

Thanks for your advice everyone. I just installed Eneloops in my H51 and LD10 and what a difference over the regular alkalines. I now see a difference with the H1 and H2. I was expecting double the output of H1 over H2, but nonetheless, I can at least see the difference between H1 and H2 when pointed to a wall.

The fact that I won't have to worry about leaking batteries is worth it alone.


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## Gregozedobe (Jan 15, 2012)

The human eye has a non-linear response to changes in brightness, so a doubling of lumens may only seem to be "a bit brighter", not twice as bright. Don't forget you can program H2 to 140 or 100 lumens. There isn't all that much difference to our eyes between 140 and 200 lumens. If you take it outside and shine it at something a fair way off you may notice the difference better.


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## Outdoorsman5 (Jan 17, 2012)

Gregozedobe is right. When comparing 100 lumens and 200 lumens the difference to our eyes appears to be something like a 25% increase. If you compared 100 lumens of output to 400 lumens of output then it'd look like the light had doubled. It's strange, but that is how our logarithmic eyes work.


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## reppans (Jan 17, 2012)

Outdoorsman5 said:


> ... It's strange, but that is how our logarithmic eyes work.



Not all that strange, it's actually a natural law of physics. For example, kinetic energy and windforce increases proportionally with the square of speed, sound and light diminish proportionally with the square of distance.

Having said that, I do think Zebralight fibs a bit. The max specs on my Quark AA^2 and ZL H51w are within 8 lumens of each other, but to my eyes, the Quark blows the ZL away even considering the ZL is a bit more floody. Also, while both have almost the exact same high > max lumen jump, the visual difference on the Quark is obvious while the ZL is difficult to perceive... on Eneloops as the ZL uses for its testing, btw.


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## theshoelacebandit (Jul 19, 2012)

I just received my new version h51 (all levels current regulated). I haven't had much time to play around with it yet. While my findings are preliminary I have noticed that there is a much more dramatic difference between h1 and h2. It appears that this has been addressed in the newest one. With the older one it was hard to determine which level you were in. Now there is an obvious difference. I use the same eneloop battery in both lights to make sure it wasn't just a battery thing.


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## Incan (Nov 2, 2012)

champ.49er said:


> I just got my Zebralight H51 and was able to program it right away. However, I noticed that there is no difference between H1 and H2. I'm using regular alkaline batteries and have tried several different alkanlines, but still not difference. I feel like my H1 is running at 100 lumens which is the same as my H2 setting and not the advertised 200 lumens. I've got an old Fenix LD10 and the H51 doesn't seem much brighter than the LD10, so I'm wondering if I got a defective light. I have so many AA batteries that I stocked up on that I had no plans to be eneloops. Are eneloops the solution or do I have a defective H51? Thanks in advance.



i noticed the same thing with that light. H1 and H2 are nearly identical, even though i only use eneloops in mine. 

I dont know if your light is defective, but eneloops are the way to go, either way. they pay for themselves pretty quickly.


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## BirdofPrey (Nov 20, 2012)

Just signed on to look into this problem. 

Friend just bought an H51w and I'm checking it out. There is zero difference between H1 and H2. Zero. Whether white walling it, outside, or staring into the LED. So, changed batteries, still nothing. 

Medium high and high are close. 

Any suggestions? Perhaps defective? 

Sent from my Transformer TF101 using Tapatalk 2


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## ZebraLight (Nov 20, 2012)

BirdofPrey said:


> Just signed on to look into this problem.
> 
> Friend just bought an H51w and I'm checking it out. There is zero difference between H1 and H2. Zero. Whether white walling it, outside, or staring into the LED. So, changed batteries, still nothing.
> 
> ...



Try it with a new, freshly charged Eneloop.


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## BirdofPrey (Nov 20, 2012)

Running a set of eneloops through the condition cycle in my Maha. 

Take them over tomorrow and see what happens. 

Sent from my HTC Thunderbolt via Tapatalk 2.


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## mattchase (Nov 21, 2012)

I just got an h51fc, I'm assuming all the h51 models use the same electronics but maybe not. Anyway, mine definitely shows a difference in brightness between all the modes using a Rayovac LSD battery.


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## BirdofPrey (Nov 23, 2012)

Ran the Eneloops. Considerable difference. Much brighter and very noticeable difference between the two high settings. 

Sent from my Transformer TF101 using Tapatalk 2


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## choppedlow (Nov 24, 2012)

I found the same thing in my H51 (H1 and H2 seemed the same). I was still happy with it being it was my first headlamp I didn't buy at the hardware store. Glad I found this thread! Should I get more time from the eneloops? If it's brighter, then great, but if I can get more time then it's a win win.


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## markr6 (Nov 24, 2012)

That's strange, I didn't notice this until last night when I was running outside. I had an Eneloop in there, I'm guessing 90% full to start. After 30 minutes on H2, I double clicked to H1 but there was no difference. However, when I got inside and it warmed up for a few minutes, I could clearly see the difference.

It's either the battery "refreshing" itself, the temp, or my eyes re-adjusting.


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## Outdoorsman5 (Nov 26, 2012)

markr6 said:


> It's either the battery "refreshing" itself, the temp, or my eyes re-adjusting.



I bet it had more to do with the temperature if it was cold when you were out, and then battery refreshing as it warmed up.


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## markr6 (Nov 28, 2012)

Stupid me...it was just the battery getting low. Those modes sure get close on a low battery...somewhat of a meter itself. I still wish it had the battery capacity indicator like the 502 though.


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## Lite_me (Nov 28, 2012)

markr6 said:


> Stupid me...it was just the battery getting low. Those modes sure get close on a low battery...somewhat of a meter itself. I still wish it had the battery capacity indicator like the 502 though.


You have discovered the way that I determine when it's time to recharge the battery in my several Zebralights. Checking the difference in output between the two high levels is a quick indicator of battery charge. It helps to have an idea of what the usual difference is though, on a fresh battery. Regular use helps here. This works on a Li-ion model as well.


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## eh4 (Nov 29, 2012)

Lite_me said:


> You have discovered the way that I determine when it's time to recharge the battery in my several Zebralights. Checking the difference in output between the two high levels is a quick indicator of battery charge. It helps to have an idea of what the usual difference is though, on a fresh battery. Regular use helps here. This works on a Li-ion model as well.



Exactly, this should be in the owner's manual.


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## Lite_me (Nov 30, 2012)

eh4 said:


> Exactly, this should be in the owner's manual.


Not sure it should be in the owners manual as it's based on experience and perception. 

I use the lowest H2 setting available on my different Zebras so as to get a better comparison on the output differences between the two high levels. Works pretty well for me. If it gets down to the two upper levels being near the same on output, you're just about out-a-juice. I usually don't let it get that close. Don't wanna be caught somewhere with a dead battery.

Edit to add: What am I saying.... I always have a backup!


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## kralyevski (Dec 29, 2012)

with my h51w if the battery (duracell 2650) is below 1.4 v i can not see the difference between h1 and h2 BUT with very same battery fresh off the charger (about 1.47 v) there is noticeable difference in the first few minutes of use and then i guess voltage drops...now i am looking forward to try it with energizer lithium AA, i read somewhere that voltage on those does not drop...


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