# Why aren't there double AA Headlamps?



## Miika (Apr 3, 2017)

One thing I have been wondering, why do the manufacturers prefer 3 x AAA headlamps, wouldn't 2 x AA be better? That I know, two AA sized 1.5 V batteries can have much higher capasity than three AAA sized 1.5 V batteries. And 2 x AA could be easily as compact as 3 x AAA. Or is it a voltage issue? Pretty much skipped my electricity classes ehh...


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## LED_Power_Forums (Apr 3, 2017)

I am no electronic expert by any means, but from what I learn of is that 3xAAA is cheaper to make than 2xAA. 2xAA requires electronic circuit to light up the led but with 3xAAA, only a resistor is needed. Normally the forward voltage of led is around 3V, so 3xAAA will give 4.5v in alkalines' case and drop to around 3v when depleted, which is the absolute minimum for the led to light up. I guess 2xAA will still need a boost circuit to boost the voltage in order to drive the led properly. With some efficiency loss in the driver circuit in 2xAA format, the 3xAAA wins in efficiency and thus can run longer with the lack of loss due to driver's absence. The story is different if the 3xAAA is regulated since regulation requires driver circuit, but still the efficiency applies. You can take a look at Fenix HL30 if you are interested in 2xAA headlamp.

Feel free to correct me if I'm wrong as I'm sure other experts will chime in sooner.  BTW, :welcome:.


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## LeanBurn (Apr 3, 2017)

Perhaps the design of a 2AA up front might be a little heavy. I had an older 3AAA light that had a battery pack at the back of the head to offset the weight of the lamp in the front, and 2 AA's are heavier than 3AAA are.

I just use a 1 AA headlamp and carry a spare.


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## hiuintahs (Apr 3, 2017)

LeanBurn said:


> Perhaps the design of a 2AA up front might be a little heavy. I had an older 3AAA light that had a battery pack at the back of the head to offset the weight of the lamp in the front, and 2 AA's are heavier than 3AAA are.
> 
> I just use a 1 AA headlamp and carry a spare.


Agree. I also just use a 1AA headlamp because its smaller and lighter and carry a spare if needed. With electronic drivers converting the battery voltage to whatever is needed for an LED, its not so important as to the battery configuration. I think what is important is weight though. As far as headlamps go, more batteries will allow for brighter output but it at the expense of more weight. If not needing the brightness, then a single AA headlamp is ideal in my opinion because most of the time headlamp use if for up close stuff.

2xAA is kind of a tricky area for drivers because at first (depending on the battery type) the battery voltage is above the Vf of the LED and later its below it. Therefore the 3xAAA voltage alleviates that problem and allows for a buck regulator without having too heavy of a headlamp. And you could hit higher output on a 3xAAA configuration than a single AA. Naturally the real cheap 3xAAA headlamps can use a resistor, but you won't find that in good name brand headlamps like the Fenix HL25.

So it is interesting that you do see a lot of 3xAAA headlamps and you don't see them so much in flashlights. I would say that is because they can be placed side by side in a headlamp without the headlamp looking out of proportion. In a flashlight they'd need to be placed end to end otherwise the ergonomics of the flashlight would be really weird.

I think 3xAAA headlamps are slowly being phased out. I know Fenix has discontinued the HL25.


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## Hugh Johnson (Apr 3, 2017)

LeanBurn said:


> Perhaps the design of a 2AA up front might be a little heavy. I had an older 3AAA light that had a battery pack at the back of the head to offset the weight of the lamp in the front, and 2 AA's are heavier than 3AAA are.
> 
> I just use a 1 AA headlamp and carry a spare.



I'm with you in this. I have the same TH20 as listed in your sig. I'd rather have a single battery headlamp and carry a spare(s). I always found it a hassle with my 3xaaa, when I wasn't sure how much battery life was left, to carry 3 extra batteries as my "spare".


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## ronniepudding (Apr 3, 2017)

hiuintahs said:


> ...
> So it is interesting that you do see a lot of 3xAAA headlamps and you don't see them so much in flashlights. I would say that is because they can be placed side by side in a headlamp without the headlamp looking out of proportion. In a flashlight they'd need to be placed end to end otherwise the ergonomics of the flashlight would be really weird.



3xaaa flashlights are all too common, they tend to be those cheap ones kept at the checkout counter at the hardware/home improvement stores. They are cheap to produce for the reason specified - simple circuitry will light the LED(s) without the need for boosting voltage. I don't know of any good lights in this format, and that includes many headlamps (Petzl, etc.). They are unregulated, and heavier than they need to be with batteries installed. I much prefer 1xaa format for headlamps and hand held lights.


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## iamlucky13 (Apr 3, 2017)

There are a few 2xAA headlamps. The Fenix HL30 and HL35 are examples.

It's more common, however, when 3xAAA or 1xAA are not powerful enough, to jump up to 1x18650.


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## Lynx_Arc (Apr 3, 2017)

Most decent 3AAA headlamps probably have a linear regulator and when they hit the same voltage as the LED they go into direct drive I figure. One reason that the 3AAA format is popular I think is greed. Battery makers are often the main source of 3AAA lights and headlamps and they sell the AAA and AA batteries for the same price. 2AA has about 60% more power than 3AAA does at 2/3rd the price. A light with a boost circuit probably loses about half the gains in power I figure so lets figure 30% more power than 3AAA. This means 3AAA costs a lot more in batteries to operate at the same light levels which means more money for Energizer, Duracell, and Rayovac in battery sales... perhaps 60% more in profits (or more). The higher output will tax the 3AAA setup more than 2AA I think even with a boost circuit meaning more difference in cost/runtime. 
It probably costs $1 more to incorporate a boost circuit than a linear regulator these days unless you are trying to push the limits on output. There are 2AA headlamps out there but for now they cost a fortune compared to the 3AAA offerings if you are buying locally. The alternative of 1AA headlamps is good but they have considerably less power than a 3AAA headlamp so unless you use a lower light level you will find yourself as I do changing the battery every few hours which can get annoying fast.


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## OldmanRon (Apr 3, 2017)

hiuintahs said:


> Agree. I also just use a 1AA headlamp because its smaller and lighter and carry a spare if needed. With electronic drivers converting the battery voltage to whatever is needed for an LED, its not so important as to the battery configuration. I think what is important is weight though. As far as headlamps go, more batteries will allow for brighter output but it at the expense of more weight. If not needing the brightness, then a single AA headlamp is ideal in my opinion because most of the time headlamp use if for up close stuff.
> 
> 2xAA is kind of a tricky area for drivers because at first (depending on the battery type) the battery voltage is above the Vf of the LED and later its below it. Therefore the 3xAAA voltage alleviates that problem and allows for a buck regulator without having too heavy of a headlamp. And you could hit higher output on a 3xAAA configuration than a single AA. Naturally the real cheap 3xAAA headlamps can use a resistor, but you won't find that in good name brand headlamps like the Fenix HL25.
> 
> ...



I suspect that Petzl will be making their 3xAAA basic Tikka and Tikkina for quite a while to come. Their new 2017 models are great value for the dollar, and comfy, and do most basic lighting jobs just fine. I appreciate and use the handy red LED in my Tikka.


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## iamlucky13 (Apr 3, 2017)

Lynx_Arc said:


> Most decent 3AAA headlamps probably have a linear regulator and when they hit the same voltage as the LED they go into direct drive I figure. One reason that the 3AAA format is popular I think is greed. Battery makers are often the main source of 3AAA lights and headlamps and they sell the AAA and AA batteries for the same price.



It's true that brands like Energizer and Rayovac have a vested interested in selling more batteries, but they also usually produce the models with the simplest regulation, which actually extends battery life at ever-declining output. It's almost a pity they aren't "greedier," if by doing so they'd switch to designs that provide more consistent output.

That said, 3xAAA was pretty well-established as the mainstream by Petzl, Black Diamond etc. before the battery manufacturers jumped in with their budget models.



> There are 2AA headlamps out there but for now they cost a fortune compared to the 3AAA offerings if you are buying locally. The alternative of 1AA headlamps is good but they have considerably less power than a 3AAA headlamp so unless you use a lower light level you will find yourself as I do changing the battery every few hours which can get annoying fast.



An efficient 1xAA light should give you around 3/4 as many lumen-hours of output as a 3xAAA light, so I'd consider them in the same general category.

It's true that you generally don't have many 1xAA options locally, but online pricing is pretty good. I was quite happy to spend $50 on my Armytek Tiara rather than stick with what was available at REI for little to no price savings. The REI light it replaced wasn't much cheaper, and was definitely inferior.


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## Lynx_Arc (Apr 3, 2017)

iamlucky13 said:


> It's true that brands like Energizer and Rayovac have a vested interested in selling more batteries, but they also usually produce the models with the simplest regulation, which actually extends battery life at ever-declining output. It's almost a pity they aren't "greedier," if by doing so they'd switch to designs that provide more consistent output.


There becomes a point however that the headlamp gets dim enough that the batteries are changed out
[quot]
That said, 3xAAA was pretty well-established as the mainstream by Petzl, Black Diamond etc. before the battery manufacturers jumped in with their budget models.
[/quote]They jumped in with their first offerings in LED format in 3AAA types while incans using 2AA were more common than AAAs. 


> An efficient 1xAA light should give you around 3/4 as many lumen-hours of output as a 3xAAA light, so I'd consider them in the same general category.


The problem with "lumen hours" is when the lumens drop too much it doesn't matter how many hours they can run at they are no longer bright enough to be useful for some tasks.


> It's true that you generally don't have many 1xAA options locally, but online pricing is pretty good. I was quite happy to spend $50 on my Armytek Tiara rather than stick with what was available at REI for little to no price savings. The REI light it replaced wasn't much cheaper, and was definitely inferior.


I have an old Rayovac luxeon 1AA I use which runs for less than 2 hours and goes out on nimh.


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## hiuintahs (Apr 3, 2017)

"3xaaa flashlights are all too common, they tend to be those cheap ones kept at the checkout counter at the hardware/home improvement stores. They are cheap to produce for the reason specified - simple circuitry will light the LED(s) without the need for boosting voltage. I don't know of any good lights in this format, and that includes many headlamps (Petzl, etc.). They are unregulated, and heavier than they need to be with batteries installed. I much prefer 1xaa format for headlamps and hand held lights."

Ahhhh yes, I forgot about those cheap 3xAAA lights where the batteries are in a round caddy. And they have the multiple 5mm bluish LEDs too. Yuk. I guess I was thinking 3xAAA all lined up side by side like they do in many of the headlamps.


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## OldmanRon (Apr 4, 2017)

Double post.


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## ronniepudding (Apr 4, 2017)

hiuintahs said:


> Ahhhh yes, I forgot about those cheap 3xAAA lights where the batteries are in a round caddy. And they have the multiple 5mm bluish LEDs too. Yuk.



Exactly! I used to frequent Harbor Freight a few years back, and they were constantly hawking those 3xAAA lights for 99 cents or something... It felt like they had an endless supply to give away, or maybe the cheap flashlights were breeding like rabbits (or Tribbles) in the back room  

Perhaps things have changed since then, at least I hope so. But I imagine there are still a lot of those semi-disposable lights being made, used for a matter of months, and then thrown in the trash. 

However, now that I think some more about it, there are some Maglites made in that same form factor. I have an XL50 that hasn't been lit up in years. There are several reasons I don't care for it (having nothing to do with the battery configuration), but I have to admit that it's pretty nicely machined if I don't think too much about the retail price tag. For the life of me though, I can't think of any other 'quality' hand held lights using that format.

Nevertheless -- and I think this was your initial point hiuintahs -- there are by comparison *lots* of headlamps using 3xAAA serial power source. I don't mean to dismiss them... Who among us hasn't used a Petzl Tikka at some point?


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## Lynx_Arc (Apr 4, 2017)

I still have plenty of 3AAA lights.... I had 2 headlamps using the "cartridges" but both of them broke and I have 4 or so 3AAA flashlights of which 3 have batteries in them that I never use at all. I also have a cheap energizer 2x5mm LED headlamp I got when headlamps were just starting to drop in price. I got several 3x5mm 3AAA headlamps for $3 on clearance and used one to change out 6 outlets and a switch in a house. I don't use any of these 3AAA lights but I do have 2 nebo type clone 3AAA lights (COB/LED) that I wish that they made 2AA models instead to increase the runtime.


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## Woods Walker (Apr 4, 2017)

Here is a 2XAA headlamp. I use it when packing gear which takes 2XAA like my GPS.


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## Miika (Apr 10, 2017)

Hmm yes carrying a spare battery with 1xAA lamp sounds like an idea for casual user. But in industrial use that is usually not an option. And in industries, many of them seem to use almost only AA- and AAA-powered lights.


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## PartyPete (Apr 10, 2017)

I had a 3x AAA headlamp and I didn't like it much. A lot of the battery compartments are poorly designed and the door hinge inevitably breaks on many cheaper ones too. 

I wanted something compact, so in my case the 1x AAA Fenix HL10 was a decent choice. It's not the brightness or longest running but still, very lightweight and convenient.


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## Lynx_Arc (Apr 10, 2017)

PartyPete said:


> I had a 3x AAA headlamp and I didn't like it much. A lot of the battery compartments are poorly designed and the door hinge inevitably breaks on many cheaper ones too.
> 
> I wanted something compact, so in my case the 1x AAA Fenix HL10 was a decent choice. It's not the brightness or longest running but still, very lightweight and convenient.


Don't forget the annoying battery cartridges with cells in opposing directions that if you try to use nimh may need a screwdriver to help pry batteries out of them and if they break there is at least a half dozen different designs so trying to find a replacement for one is like an easter egg hunt on halloween.


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## iamlucky13 (Apr 10, 2017)

Miika said:


> Hmm yes carrying a spare battery with 1xAA lamp sounds like an idea for casual user. But in industrial use that is usually not an option. And in industries, many of them seem to use almost only AA- and AAA-powered lights.



Are you talking about it simply being inconvenient in industrial use, or some other factor?


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## Miika (Apr 11, 2017)

iamlucky13 said:


> Are you talking about it simply being inconvenient in industrial use, or some other factor?



Mostly about the inconvenience of replacing batteries once in a while.


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## mustbeme (Apr 11, 2017)

I had an old Petzl micro that was a 2x AA up front. The old Petzl Mega had a 4x AA in the rear. Just a form factor issue I guess with AAA working better on the front of your noggin


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## brighthead (May 25, 2017)

I have the Petzl Pixa 1. It has 2xAA. 
I got it years ago because I was asking the same questions as you.

It is heavier on the forehead than 3xAAA models I have tried, which is my main complaint about it. It also doesn't seem to last much longer, battery-wise (but then again it has only one brightness mode & nothing else, so that could very well be a big part of it). It's possible you can find something lighter than this, because it really is a 'beefy' headlamp designed for industry use (something that means very little to the way I use it). 

Anyway, my point is that weight on the forehead might be something to keep in mind.


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## Hugh Johnson (May 28, 2017)

iamlucky13 said:


> There are a few 2xAA headlamps. The Fenix HL30 and HL35 are examples.
> 
> It's more common, however, when 3xAAA or 1xAA are not powerful enough, to jump up to 1x18650.



This makes sense. Once you're dealing with multiple AA's it's getting big and heavy. You may as well migrate to 18650 at that point, which is still light, and much more powerful.


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## Tac Gunner (May 29, 2017)

I have the Fenix HL35 2xAA headlamp and love it.
http://www.candlepowerforums.com/vb...HL35-mini-review-w-pics&p=5101033#post5101033


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## Sarratt (May 30, 2017)

I've been using a fenix hp30 for years ..... I was hoping it would die so I could get Tac Gunners recommendation above me . ( HL35 )


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## Jammer Six (Jun 2, 2017)

I go along with the weight theory. Lighter is better in a headlamp. I'm looking for a headlamp for sailing, and I need it to have a red lense option. I'm replacing what I have because of weight.


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