I just got my H51. The highest level which they claim to be 200lm is obviously not as bright as my Fenix HL20 at 105lm (the spill beam spread and hot spot of the two is about the same). Furthermore, I can't tell the difference between the two level at high. It seems there is not two sub-level at high level.
(High: H1 200 Lm (0.9 hrs);H2 100 Lm (2.1 hrs) )
Is there any problem on my HL51?

Edited by syoten on 09/25/2010 09:51:02 MDT.

Have you tried a different battery? Maybe you got a dud. If that doesnt make a difference, I would pose your question to Zebralight and see what they say.

I have an H51 on order but also have an H31

Id try a few different batteries as there should be
two High modes unless the batt yer trying is a bit
low. its really pushing the lumens off of a single AA.

I LOVE my H31 and prefer rechargeable lithium - the
H51 is for my GF who wants AA simplicity

theres an H51 thread on CPF
good luck!

I just tried to use another battery, and the problem is solved. I does have two sub-level at high, and it's really bright!

However,isn't it fully regulated?
Both two batteries I tried are unused alkaline batteries, so I thought at least it should work on high level for a short time even though the fist battery is not as good as the later one.
The battery I tried at the first time on the left.


I like the brightness levels of H51, but I don't like it turns on from high since I usually don't need it that bright, and turn on from high may waste some energy everytime when I turn on it. Furthermore it may destruct my vision in darkness suddenly. I think The memory function of Fenix headlamps is better.

Now I have to get used to press it instead of click to turn on it from low.

Comparing Fenix HL20 with Zebralight H51 at their highest level. It maybe a little difficult to tell the difference between 105lm and 200lm from this picture. But I can feel the brightness of HL20 at 105lm is between two sub-levels at high of H51.


My H51 headband setup.

Edited by syoten on 09/08/2010 22:51:44 MDT.

You might try the Sanyo Eneloop. That seems to be the go-to AA battery among a lot of the flashaholics. They work great for me. I just ordered an h51, looking forward to using it.

I've upgraded to Eneloop. It does push the light to the brighter condition! It's the best headlamp I've ever used so far.

Edited by syoten on 09/23/2010 09:37:29 MDT.

I've heard of Sanyo Eneloop. Seems to give more power. But does the power 'drop off' at a shorter/steeper curve than others? And how good is it in retaining power between charges? Thanks in advance.

Eneloops don't self discharge at nearly the same rate as regular NiMH batteries. This is why they can be sold pre-charged and ready to use, and also can sit around in a flashlight all season, and still be ready to go when you need it.

Duracell has a pre-charged battery on the market with identical specs as the eneloops. These are easier to find in stores around my part of the country. I think they probably come from the same factory, and have a logo slapped on them.

+1 on the Eneloop type batteries. They do have a slightly lower maximum capacity than normal high-capacity rechargeables, but their slow self discharge rate more than makes up for this in my experience.

the NIZN AAs work great in the
H51 as well and have a bit higher
voltage under load so are a tad brighter
on max.

Im diggin my H51 tho I prefer the smaller
and slightly brighter H31

Im waiting on the H61 tho as 18650 is my fav batt
config.
good stuff!

I only use lithium batteries in mine. Supposed to last longer and have a very long shelf live.

They also work in very cold weather. Other batteries fail quicker in the cold.

They are also more environmentally correct, if that matters to you.

the NIZNs are rechargeable -
which lithium are you using?
most rechargeable lithium AA (14500) are
3.7 volts and WILL FRY the board of the
H51 zebralight.

if yer using primary lithium - say
energizer L91 (~1.6v) I dont see how thats better
environmentally since theyre disposable rather
than reusable. Eneloops or similar will last
for TONS of cycles and Ive had good luck with
the NIZNs too (around 20 cycles so far and all good!)
the primary lithiums do have more capacity but are $$
and disposable.

Edited by psychbeat on 09/24/2010 01:51:34 MDT.

I don't use recharbles and/or alkaline except in the summer months. But I, don't use headlamps that much in the summer so they don't get that much use.

I do use them a lot in the other three seasons where the daylight hours are less.
Recharbles don't work in cold temps, alkaline barely work, but die quickly in the cold.

And since I use my headlamps a lot more in cold weather for reading and hiking in the dark, I am forced to use standard AA lithium's.

They don't pollute the way other batteries do, contain less toxic substances.

Lithiums store their charge far longer than other batteries, last far longer, work well in the cold and are much lighter.

The new "A" series Eneloops have even lower self-discharge and better low temp performance (down to 10 F), than before. I have used a lot of different ni-mh and ni-cad rechargeables over the years, and have never had any other cells that performed as well.

Of course it's true that lithium primaries have even lower self-discharge and better low temp performance (although they don't work that great if it's really cold, then you need a remote pack next to your body). But for me, it's hard to justify using any primary battery as EDC. I often carry Li primaries as back-up on camping trips.

>The new "A" series Eneloops have even lower self-discharge and better low temp performance (down to 10 F),

The Sanyo site says the old ones were good down to -10C, and the new ones are good to -20C. That would be 14F (old) and -4F (new).

Where can I get the new ones, though? I just googled & cannot find them for sale.

-- MV

Some Costco stores have the new Eneloops, and some of the vendors on Amazon do as well. I just ordered a package with a charger (that I don't need) and both AA and AAA batteries from Amazon. I plan to do some testing to compare Li vs Eneloop performance at various temps in my H51. In the meantime, check out this link:

http://www.candlepowerforums.com/vb/showthread.php?t=241606

And a link for the new Eneloops:

http://www.amazon.com/Sanyo-Eneloop-Charger-Rechargeable-Batteries/dp/B003VLAEPQ/ref=sr_1_8?s=gateway&ie=UTF8&qid=1285445060&sr=8-8

Edited by zemmo on 09/25/2010 14:06:40 MDT.

> Some Costco stores have the new Eneloops, and some of the vendors on Amazon do as well.

I must be using the wrong search string at Amazon -- I still cannot find them. Even the packs that say "New" on them are the old ones. Everything I saw had the old part number, or referred to one year, 85%, or 1,000 cycles -- any of which means old ones. I saw no packaging that looks like the new blister pack that the Sanyo site shows.

I'll have to check out my local Costco -- I am worried that I'll have to buy a ton of them there, though. Costco online only has two hits for "Eneloop" and they are both the old ones.

edit: I missed your link first time -- I agree those are the new ones. Problem is all the unwanted stuff -- to get 8 AA's I have to also get a charger and 4 AAA's. 8 AA's should be under $20; this combo is $34.95 (for 8 AA's + stuff I do not want/need).


--MV

Edited by blean on 09/25/2010 14:49:33 MDT.