2AA, NiZn, and incandescent: a winning combination?

[Paul_in_Maryland]

When I decided to migrate from lithium-ion cells to AA lithium-free cells, I moved on from incans; the voltage just wouldn't be there, at least not in a 2AA body. Sure i could run a 3.7V D26 lamp assembly with three 1.2V NiMH cells in a 3AA. But 3AA is an awfully long body to put up with just 100 or 120 lumens.

But nickel-zinc AA cells promise to make incans practical in a 2AA body. With 1.6 to 1.8V per cell--under load--a pair of NiZn cells might be able to drive a high-performance (2-amp) 3.7V lamp incandescent assembly to decent levels. And the voltage discharge curve is about as flat as a lithium primary L91 cell: You get nearly full voltage till you're of electrons.

What do you think? Can--will--NiZn AAs inspire a small-incan renaissance?

I've just received my first dozen NiZn cells. After I've charged them up, I'll test them with my one remaining 3.7V incan lamp assembly and report back.

 

[jaundice]

What prompted you to move away from li-ion cells?

-John

 

[Paul_in_Maryland]

• LEDs were becoming more efficient every year; I could now look forward to acceptable levels of light using off-the-shelf cells.

• I didn't want to have to worry about which lights and which cells I could pack, or carry, when boarding an airplane.

• Eneloop AAs could hold a charge for months as well as lithium-ions.
• NiZn cells would provide a flat discharge curve and more "juice" with safe chemistry.

• (Added: ) With AAs, I could give away a light--to a friend or loved one, or simply to a stranger in need--assured that they can feed it the batteries it needs, conveniently and safely.

 

[fivemega]

• LEDs were becoming more efficient every year; I could now look forward to acceptable levels of light using off-the-shelf cells.

• I didn't want to have to worry about which lights and which cells I could pack, or carry, when boarding an airplane.

• Eneloop AAs could hold a charge for months as well as lithium-ions.
• NiZn cells would provide a flat discharge curve and more "juice" with safe chemistry.

• (Added: ) With AAs, I could give away a light--to a friend or loved one, or simply to a stranger in need--assured that they can feed it the batteries it needs, conveniently and safely.

• In case of emergency (EMERGENCY) you can get AAs from every corner.

 

[Benson]

When I decided to migrate from lithium-ion cells to AA lithium-free cells, I moved on from incans; the voltage just wouldn't be there, at least not in a 2AA body. Sure i could run a 3.7V D26 lamp assembly with three 1.2V NiMH cells in a 3AA. But 3AA is an awfully long body to put up with just 100 or 120 lumens.

An excellent point. I don't suppose I need to mention that's why you should use Li-ion -- get that voltage from 1xAA long, or even 7.4V from 2xRCR2 :nana:

But you can get 3xAA other ways -- have you looked at 1D Mags with 3xAA carriers? Could offer you 3.7V from 3sNiMH, or >5V (enough for high-drain two-cell lamps?) from 3sNiZn....
Or even, with a bored body (or with scarcer carriers and careful selection of cells), 4xAA gets you to 4.8V from NiMH or >6V from NiZn.

But nickel-zinc AA cells promise to make incans practical in a 2AA body. With 1.6 to 1.8V per cell--under load--a pair of NiZn cells might be able to drive a high-performance (2-amp) 3.7V lamp incandescent assembly to decent levels. And the voltage discharge curve is about as flat as a lithium primary L91 cell: You get nearly full voltage till you're of electrons.

IMO they'll be a little low for a 3.7V bulb; what (if any) bulbs do people use with a single LiFe cell? Are there any 3V bulbs that can take the extra push?

Admittedly, the only thing I've really messed with incans for is high-output stuff, so I'm not at all familiar with what bulbs are available for low-voltage stuff. For a while I was thinking of rigging a "poor man's A2" (regulated, single 18650 or maybe 2x18350, incan w/ LEDs), but a quick look around made me think there wasn't much in the way of single-cell bulbs, and I pretty much dropped the project.

What do you think? Can--will--NiZn AAs inspire a small-incan renaissance?

I personally doubt it -- as LEDs improve, small incans have increasingly little reason to exist. Big incans (i.e. north of 1klm) still do stuff no LED can, but for 2-cell lights, I don't think there's many people who'll take 100 CRI over 93 CRI with substantially better output and/or runtime.

From the other side, most of the incan fanatics don't mind Li-ion or Li batteries, so unless you can actually beat 6V of primaries, or 7.4V of Li-ions, there's not likely to be a whole lot of interest from them.

But by all means, don't let my wetblanketness bother you -- I am very interested to hear how this works out.

 

[ampdude]

• In case of emergency (EMERGENCY) you can get AAs from every corner.

I used to think that, but I'm not so sure anymore. Everytime there is a storm, people clean all the milk and bread off of the shelves. And also, depending on things, all the ammunition and batteries.

I mostly use rechargeable NIMH AA's and IMR 16340's, but I like to have a reasonable supply of lithium CR123a and Alkaline AA's & AAA's sitting around. At least 50 of each or so. (just in case)

 

[Paul_in_Maryland]

An excellent point. I don't suppose I need to mention that's why you should use Li-ion -- get that voltage from 1xAA long, or even 7.4V from 2xRCR2

Lithium-ion Safety issues were just too problematic, both for me and for anyone to whom I might give or lend the light. And I found myself unable to standardize on just one cell size: I had 18650 bodies, 17670 bodies, and 18500.

But you can get 3xAA other ways -- have you looked at 1D Mags with 3xAA carriers? ...

I prefer to standardize on lights that use a D26 drop-in. I find that AA lights can carried more easily and less conspicuously. Also, I've been able to standardize on bezels (Solarforce) and traffic wands (Streamlight Strion), which I keep stashed in my coats and commuter bag. (I recently directed traffic with such a setup in downtown Washington, DC, when a dump truck spilled its load of scrap metal and the truck's occupants scrambled to clean up.)

IMO they'll be a little low for a 3.7V bulb; what (if any) bulbs do people use with a single LiFe cell? Are there any 3V bulbs that can take the extra push?

That's a good point. Even when fully charged, NiZn AA cells start out on the low side of 3.7v. Even the Malkoff M30 series is unregulated below 3.6 or 3.7V. More and more newer LED drop-ins are regulated at lower voltages: the Malkoff M61 (3.4V), Dereelight (under 3V), and Thrunite (under 3V), to name three. But incan lamps would have to be retuned to NiZn's voltage levels.

From the other side, most of the incan fanatics don't mind Li-ion or Li batteries, so unless you can actually beat 6V of primaries, or 7.4V of Li-ions, there's not likely to be a whole lot of interest from them.

That's true. Enthusiasts are usually willing to put up with more inconvenience and risk for that extra margin of performance.

 

[leukos]

I've just received my first dozen NiZn cells. After I've charged them up, I'll test them with my one remaining 3.7V incan lamp assembly and report back.

 

[Phaserburn]

I would like a 2 x Nizn bulb option; haven't tried it with mag bulbs yet to see if a 2 cell could stand the overdrive.

I currently am using 4 x nizn cells in my PT Tec 40 with a Mag 5 cell bulb; the voltages line up nicely (4 x 1.6V (under load) = 6.4V, vs 5 x 1.2V = 6V) and it's a nice performance boost to boot. Yes, the bulb is rated 6V, but new alks supply 7.5V, so I know the bulb can withstand the 6.4V without being really overdriven.

 

[Paul_in_Maryland]

2AA/3AA, NiZn, and Lumens Factory xenon: a winning combination?

Lumens Factory makes four medium- and high-performance D26 lamp assemblies that line up nicely with 3 NiMH (corrected from "2 NiZn") or 3 NiZn AA cells.

Lamp Specification (D26 Series) from the Lumens Factory specs page:

rated 3.7V, for 3 NiMH AA cells:
HO-4 1.8 A, 150 lumens
EO-4 2.35A, 190 Lumens

Rated 4.8V, for 3 NiZn AA cells:
HO-6 1.4A, 160 lumens
EO-6 1.9A, 200 lumens


Added: Call me impulsive, but 15 minutes after posting these specs, I ordered one of each direct from Lumens Factory. Total shipped cost to USA: $63

 

[ampdude]

Have you found any decent Surefire compatible 3AAA bodies to run them in? That would be a 4 and a half cell C/D/Z/P/G body. I have a Balrog 4 cell E-series body and a Dspeck AA extender that I was thinking of running a lamp or LED off of with 3AA batteries and a half CR123a dummy cell.

 

[Phaserburn]

Interesting; I didn't think to check out the 6V lamp specs for use with 3 nizn cells. What host are you running the 3AAs in, Paul? This sounds interesting to me.

 

[Paul_in_Maryland]

I am the proud (and poor) owner of three FiveMega 3AA bodies.

I also have a Dereelight Javelin 2AA that can be used as a 3AA with the extender, but I haven't decided yet which Javelin length I prefer.

 

[Paul_in_Maryland]

For anyone contemplating the Surefire P61, there's a useful discussion in this thread about P61 and rechargeables. Evidently, the P61 needs cells that will deliver 4.2 to 4.4V under load but will flash at 4.8V under load. I'll let you all know whether the Lumens Factory lamps die a sudden or early death on 3 NiMHs (4-series), 4 NiMHs (6-series), or 3 NiZns (6-series).

 

[Outdoors Fanatic]

• In case of emergency (EMERGENCY) you can get AAs from every corner.

In case of a real emergency, you might-- and probably will-- be very far from a "corner". This is just about the most ridiculous argument in favor of alkaline chemistry. Lower price and availability? Defintely yes. "Emergency" situations? Please, enough of this armchair survivalist munbo-jumbo... I only get to hear this nonsense at CPF.

 

[Kestrel]

Valid point - in a true emergency, AA's will be 'sold out' at every corner.

However, I would agree with FM if we are talking about a 'flashaholic emergency' where the main populace is their normal :candle: but we happen to find ourselves with depleted rechargeables and without high-quality reserve cells.

 

[Paul_in_Maryland]

Beam shots: Lumens Factory xenons (3AA) vs Dereelight XPG-R5 (2AA, 3AA)

My four 3.7V and 4.8V lamp assemblies arrived from Lumens Factory, and I couldn't wait to test my theory: That they would produce a lot of light, without hot-flashing, from 3 NiMH AA cells ((the 3.7V lamps) or 3 NiZn AA cells (the 4.8V lamps).

Here's how they arrived in their boxes. Clockwise from upper-left: HO-6 (4.8V, 1.4A), EO-6 (4.8V, 1.9A), EO-4 (3.7V, 2.35A), HO-4 (3.7V, 1.8A).

Open the boxes, and you find each lamp shock-mounted in a clear cylinder. Nice.

Each cylinder's lid is clearly labeled.

My plan was to test them in a battery of bodies. Left to right: FiveMega 3x18650 body (3x18500 + 102mm extender); three FiveMega 3AA bodies; Dereelight Javelin 2AA; Underwater Kinetics (UK) 4AA with side switch (2AS version). Each FiveMega body is fitted with a SolarForce bezel.

For the AAs, I used Sanyo Eneloop nickel-metal hydride (NiMH)...

and PowerGenix nickel-zinc (NiZn).

Using a MAHA C-9000 AA charger, I had briefly discharged each cell under a 1-amp load--the highest load at which the MAHA could discharge a cell. The Eneloops were pushing, on average about 1.23V; the PowerGenix cells, 1.64V. Multiplied by 3 would yield about 3.7V and 4.9V--perhaps 3.6V and 4.8V at 2A. In other words, both cells seemed ideal for testing the 3.7V and 4.8V xenon lamps: Not too weak, not too strong (pop!).

All tests were conducted indoors against a shooting target mounted to my Pepto-Bismol pink basement wall, from a distance of 3 meters (10 feet). All photos were shot in RAW with my Fuji FinePix S7000 bridge camera at ISO 200, f/5.6, 1/60 second and processed in Adobe PhotoShop Elements 7. I didn't adjust the exposure; just the channel balance.

On with the beam shots.

As a reference, I began with my Dereelight XPG-R5 LED module (single-mode). The Dereelight is regulated from (I think) 2.4V to 4.2V.

Dereelight XPG-R5 (1.2A), 2 NiZn AA cells (3.2V):

Dereelight XPG-R5 (1.2A), 3 NiMH AA cells (3.7V):

In the preceding two photos, the XPG looks equally bright under both sets of cells. My color balancing must have altered the appearance, for I find that when I feed it 3.7V instead of 3.2V, the spill is brighter, more useful.

The Lumens Factory HO-4 (1.8A) was a no-go: It hot-flashed as soon as I powered up the 3 Eneloop cells.

Lumens Factory EO-4 (2.35A), 3 NiMH AA cells (3.6V):

Like the HO-4, the HO-6 was destroyed when I tried to power it from 3 AA cells. Only this time, the cells were the more potent nickel-zincs...and instead of hot-flashing, the springless HO-6 shorted out in the Dereelight Javelin:

Lumens Factory EO-6 (1.9A), 3 NiZn AA cells (4.8V):

I nearly gave up getting the EO-6 to light up at all. In two of my three FiveMega 3AA bodies, it was too short to make contact, with or without a spring. Luckily, I'm one of just two CPFers to own three of these bodies; the EO-6 worked in the third one. I suspect I would have had better luck had I tried it in my Dereelight with the 3AA extender.

Just for kicks, I included the Underwater Kinetics 4AA (5.1V, 430mA) with its stock 2W xenon lamp assembly. Powered by NiMH cells, the UK was simply outclassed.

No doubt, UK's 4-watt lamp assembly, designed for the 4AA's rechargeable version, would have fared better. But that lamp assembly is no longer made, and I did't feel like buying one at about $15 just to run a test. The only reason I bought the UK 4AA body was to see whether it would accept a D26-size module. (It doesn't.)

Here's an unfair match: The 9-watt Lumens Factory EO-6 (top) vs. the Underwater Kinetics 2-watt xenon:

And finally, the 9-watt EO-6 (top) vs. the 8.7W EO-4:

The two lamps are rated 200 and 190 lumens (EO-6 and EO-4), yet in these photos, the EO-6 has a noticeably brighter hot spot. I'm guessing that the EO-4's highter current (2.35A vs. 1.9V) is causing voltage sag.

Conclusion:
The Lumens Factory xenon lamp assemblies are not recommended for use with NiMH or NiZn rechargeable AA cells. The High Output (HO) lamps can't take the voltage. The Extreme Output (EO) lamps don't seem to achieve their rated brightness; moreover, they require multiple presses to power up and some experimentation (with and without spring) to make contact.

 

[ampdude]

Oh darn, I was really hoping the NiZn batteries would power a P60 nicely. :shakehead If it popped the HO-6 it's probably a no-go.

Did you let the NiMh batteries rest at all before the test? What was their measured voltage off of the charger?

You didn't charge the NiZn's with the C-9000 did you? I didn't think the C-9000 could charge those battery type. Though I'm hoping they'll release a version that will, or a firmware update.

 

[Paul_in_Maryland]

It had been at least 2 weeks since the Eneloops AAs had been charged. I probably even had used them a bit; as reported, each cell's voltage under a 1-amp load was lower than 1.25 volts.

Don't worry, I hadn't charged the NiZn cells in the MAHA. I used PowerGenix's own "fast" charger.

I never managed to light up anything in my FiveMega 3x18650 (4AA) body. That's why I'm looking to trade it.

 

[ampdude]

Yea, I was really hoping that would work with the NiZn because I have a VG3 and a Dspeck AA extender. I could just get an E-C adapter and a head and run P60's guilt free.