Looking for a ultralight headlamp: Mammut S-Lite or Mammut S-Flex?

"I may be wrong, but I read that a single AA doesn't provide a good voltage to drive current LEDs efficiently and so they use a regulated PWM circuit to raise the average voltage to an efficient voltage level, something higher than the 1.5 volts of a standard AA."

That is correct. A common LED can light up on 1.5 volts. However, the brighter ones require more voltage, like 2 to 3 volts. The device that takes 1.5 volts and produces 2 or 3 volts out of it is called a charge pump.

"The argument for the many 3xAAA lights is that they should be more reliable because there is no PWM/regulator circuitry to fail, but I find that the extra wiring and contacts can fail on 3x lights making them just as unreliable."

Yes. In the old days, the PWM/regulator/charge pump was not reliable, too large, or too inefficient. The modern ones have that solved.

"I believe that a durable regulating circuitry can be made and from what I have seen the Zebralites have proven to be quite reliable."

Yes, you can learn something by opening up a Zebralight at the battery compartment and looking down to see the circuit. If you dropped it from a sufficient height, you could break it.

–B.G.–

Ordered a Fenix HP11 recently for some night time running, mine exploring, etc. 4 lumen settings: 277, 133, 55, and 4. Overkill for backpacking and heavy @ 6.3oz without batteries (4xAA). Reviews all seemed positive, and $38 on eBay was too hard to resist. If I like what I see, I'll be picking up their lighter headlamp, the HL21, 3 lumen settings: 90, 43, 3. 1.75oz without batteries (1xAA).

Currently using a older Petzl Tikka, and during my last trip to Death Valley, the light output left a lot to be desired, especially in some mines. Luckily my friend had a 100 lumen Surefire flashlight that lit the way. What was crazy is a couple people showed up during the night at the cabin (in Panamint City, left over from the mining days) we were staying in and one of them was carrying a full size Maglight. Anyone have the weight on one of those suckers?

>> What was crazy is a couple people showed up during the night at the cabin (in Panamint City, left over from the mining days) we were staying in and one of them was carrying a full size Maglight. Anyone have the weight on one of those suckers?

On my scale, it's 24.1 ounces for the standard full size with two (dead) D-cell batteries. I can only imagine what the 6-cell skull-crusher weighs in at!

Sure, you can get lighter… But this monster is multi-use… flashlight, wheel chock, tire-inflation gauge (listening for the "pop" is lost on kids these days), and aforementioned skull-crusher. Not doing that with my BD Spot!

>> "On my scale, it's 24.1 ounces for the standard full size with two (dead) D-cell batteries."

Imagine what it weighed back when the D-cells were full of electrons!

Going to give it a shot. Anyone have a source for cheap(er) Energizer L91 Ultimate Lithium batteries? :)

http://data.energizer.com/PDFs/l91.pdf

Bryce, I use the SC50W.
I think the regulator circuit used has a big effect on efficiency, as does the LED "emitter" used in the construction of a flashlight. The combination of quality construction, high(est?) quality parts and a great user interface are what makes Zebralight's great. ALSO 1st class customer service.

I had owned my Zebralight for well over a year when, through my own clumsiness, dropped it doing a night walk up the "Thousand Steps" in Ferntree Gully here in Aus. Fell from about chest height onto concrete, broke the front glass and the regulation circuit. It seemed to then operate on a fail safe or something because it still worked, only it was stuck on a medium light output mode and the only way to switch it on or off was by twisting the tail cap. I was not left stranded in the dark, I still had light!

When I mentioned my mistake to the folk at Zebralight, on the off-chance it might be repairable, they asked me to send it to them. They FIXED IT FREE of charge and PAID TO SHIP IT BACK TO ME, it was like new again!

In regards to batteries, I use NiMH as they have better characteristics than alkalines (last longer in my flashlights, have flat discharge curves) and it is easy to ensure they are full to the max of their capacity before heading out. To top it all off, they're much better for the environment too!
You do need to ensure you have a decent charger for them to look after them though, and the LSD (low self discharge) type are best. Heaps of info over on batteryuniversity.com and on candlepowerforums.com

I can't refute the thought that rechargeables are best for the environment, but Lithiums win hands down for weight, longest lasting, and ability to perform in really cold temps.

The S-flex headlamp worked really well, I had no trouble night hiking with it on medium. I'm switch to high if I was searching for a blaze in a difficult area.

The only annoying thing about the s-flex is that the headband tends to come off once in awhile. Overall it was great for winter camping for me.

White LEDs typically require 3.3V to 3.5V for maximum brightness (the exact voltage will depend on the manufacture and construction). There are two ways to regulate the voltage to the LEDs.

1. Wire the batteries in series to get more than the required voltage. 3AA or 3AAA batteries wired in series would provide 4.5V. 2AA or 3AA batteries in series would not be enough unless you want a very dim light. The regulator circuit take the voltage and turns it on and off very fast, breaking it into pulses of power. These are then combined to create the needed voltage. With fresh batteries the pulses are further apart. As the batteries are drained the pulse frequency increases. Once the voltage from the 3 batteries drops below 3.3V the light will start to dim. Eventually getting so dim that it isn't usable even if power is still available in the batteries.

2. The second method is similar the battery power is pulsed on and off and then is sent through an inductor. The inductor converts the Voltage pulse into a current pulse which is then supplied to the lEDs. This method can efficiently reduce the power to to the correct voltage or increase the voltage if the battery voltage drops below 3.3V. In fact it is possible to take voltage from a single 1.5V batteries and boost it to 3.3V. This methode can extact the maximum amount of power out of the batteries. This circuit can be made from 2 to 4 parts and can occupy an are equal to 3 dimes stacked. Light output will be constant until the battery is almost completely dead. At that time the light will start pulsing on and off and then completely die.

If you are locking for a LED headlamp I would go to REI if there is one nearby. I work near one and they have one display about 4 feet highy by 5 or 6 feet wide full of LED headlamps (about 3 or for brands with several different models from each). You can quickly compare light output in lumens, battery life, weight, and other features.

I did this and selected a prinston tech fuel, a 43lumen head lamp which produces more than enough light for me (on medium) and will stay at full brightness for about 120hrs on high with 3AAA batteries (1.5oz without battereies).

As to batteries you can use any brand you want as long as the battery fits and has the correct voltage. Do note use a battery that puts out more voltage than recommended by the manufacture. There are 1.6V AA rechargeable batteries on the market that can damage electronics. Everedy 1.5V lithium batteries will work find in any AAA or AA powered head lamp.

"Everedy 1.5V lithium batteries will work find in any AAA or AA powered head lamp."

Stephen, a new 1.5V lithium battery will have an open circuit voltage of about 1.6V.

It is a little misleading to say that there are 1.6V AA rechargeable batteries on the market that can damage electronics. It would be much more accurate to say that there are some electronic devices that are designed for 1.5V batteries, and 1.6V batteries could damage them. It isn't the fault of the batteries.

–B.G.–

Yes with a meter some batteries can show an open circuit voltage higher than the label. But open circuit voltages are not important. The voltage a battery can produce with a load is determined by the cemistry and physics inside. A battery labeled 1.5V cannot maintain a voltage higher than its label once the load is conected. The voltage very quickly will collaps to 1.5V under load.

The 1.6V batteries I was refereing to are Nickel zinc rechargables. They came onto the maket only a couple of years ago and were advertize as compatable with any AA or AAA device and would power a device longer. reports of device failure quickly followed. Open circuit voltage may or may not be higher than 1.6V. But under load a 1.6V battery will maintain 1.6V and that can cause electronics to slowly overheat or fail quickly. Semiconductors are not very forgiving to voltages higher than rating unless the designer put in some sort of protection for this. Often there is no requirement for such protection to be added and the manufacture won't state this in the manual. Most manufactures arn't even aware 1.6 batteries are on the market.

If the manufacture recomends 1.5V batteries use batteries labeled 1.5V. Batteries with voltages lower than the device rating won't do any damage but there is no guerantee that the device will work correctly or ever turn onn. Becides 1.2V rechargables have been on the market for decades and manufactures typically verify 1.2V rechargables won't cause permanent damage.

"A battery labeled 1.5V cannot maintain a voltage higher than its label once the load is conected. The voltage very quickly will collaps to 1.5V under load. "

Steve, this is utter nonsense. You need to get a better meter.

I have lithium AA cells here that start out open circuit above 1.6V and drop down to 1.55V even at moderate loads.

Part of the problem is that many modern devices such as LED lights draw very little amperage, and that is so small that the battery voltage does not get pulled down very much. Plus, in the first instant that the device is connected to the battery, you will see the full open circuit voltage, so it is normally that first instant when the device gets "frapped." By the second instant, the internal series resistance of the battery is in effect, so the voltage is less and the device stands a better chance of survival. Lithium primary batteries have a huge short circuit current capability, and you can do some real damage with them.

The more typical device to get frapped is not a headlamp, but an older GPS receiver.

–B.G.–

Are the Zebra Lights really that good?

Re: "Are the Zebra Lights really that good?"

I guess it's a matter of opinion. They are pricey.

My wife and I have been both using them exclusively for a couple years now and like them better than the past 10 or 20 lights we've used.

Light, waterproof and flexible.
You can go a long time on one AA if you stick to using the lowest setting most of the time.

I have hiked with the lowest setting when I had a moon, but had to use the middle setting on overcast nights.

"Are the Zebra Lights really that good?"

How good do you expect?

I purchased one last year, model H501, and I am happy with it. It is similar to H51. The head strap is very good, but a little too heavy. I replaced it with something lighter, and I brought the overall solution (headlamp, strap, battery, etc.) down under 2 ounces. I've used it for night hiking, and it is fine at its intermediate level of light intensity. I've used plenty of 8-ounce headlamps before, and I don't need another one.

First of all, you want to decide how much light intensity you need, measured in lumens. Most of us say that we want a durable low intensity for around-camp use or map reading, maybe 20 lumens or less, but we want a high intensity for something far off, maybe 100 lumens. That's OK, because many of the modern LED headlamps have multiple intensity levels on the switch. Several manufacturers offer the intensity that you need. If you are a policeman, maybe you want 500 lumens.

How much light duration do you need? In general, the low intensity lights will last a long time, and the high intensity lights are much shorter. Different battery types carry different amounts of ampere-hours. Several manufacturers offer different battery solutions, so you can get the duration you need. Some backpackers choose the battery type based on what other devices they carry require. The thinking is that they can carry only one single spare battery to use for two or more devices, like headlamp plus GPS. Also, a long-distance through hiker may be concerned about a battery type which can be easily purchased in some little store out in the middle of nowhere, so they decide on AA size or something similar.

Some people care about the color of the light, as there are cool and warm shades of white.

Some people want to do solar recharging along the trail. Good luck with that. The general idea is that it is less weight to carry one single spare lithium battery rather than going through the solar hassle, but that applies to shorter trips under a couple of weeks. As you get to very long trips, the solar hardware might start to prove in. Maybe not. So, some people choose rechargeable batteries for this.

Some people want it cheap. That's OK. I've noticed several decent models on the market lately (much cheaper than Zebralight), but the specifications aren't quite as good.

–B.G.–

I've been using my BD Spot for years now. Heavy but it does what it's supposed to do. I was thinking a Petzl E Lite for my CT hike since I don't see myself doing much at night. No need for a super bright light while sleeping.

Lots of really good info in this thread. I'm trying to decide between the Zebra H25 and the e+lite. I'd rather replace a single AA than try to find a store with two watch batteries.

"I'm trying to decide between the Zebra H25 and …"

There is no such thing.

–B.G.–

Obviously a typo for H52.

I used to carry an e-lite and just switched to an H52. The e-lite is awesome for an ultralight headlamp used around camp. But the limited lumens and the poor durability of the switch drove me to look for another alternative, even if heavier. The H52 has 3 great levels, as the low works great for reading, the medium for hiking, and the high when needing to search down or off the trail. It's also waterproof. It weighs around 3 ounces with an eneloop and headband, however. For me the H52 is superior in every way except for comfort (minor edge to the e-lite) and weight. Good luck on your decision.