MDC 1xCR123 vs 2xAA Lithium

[jd101]

Hi everyone,

I'm having trouble deciding between these two for briefcase-carry and night table use. The Malkoff website says that the runtime/lumens are the same for each. Is there any difference whatsoever between 1xCR123 and 2xAA lithium other than form factor, and perhaps battery availability depending on location? I'm far from being an Electrical Engineer, and can't figure out why the specs are the same -- why doesn't the 2xAA Lithium have 'more' than 1xCR123?

Thx.

 

[thermal guy]

There basically the same thing.Just form factor as you say. AA are only 1.5 volts as compared to the 123 that is 3-3.2 volts. Neither one is pulling a lot out of the cells as malkoff goes more for dependable over horse power. I prefer the AA as cells can be had anywhere.

 

[jd101]

Thank you. So the second AA gets the same voltage to the LED as does one 123 so the LED lights up, but doesn't extend the brightness or the runtime?

 

[xxo]

Two AA L91's should give more than doule the runtime as a single CR123A, all else being the same.

 

[thermal guy]

Well not really. When you run batteries like this you double the voltage not capacity. So one 123 and 2X L91's is pretty much the same capacity

 

[treek13]

Well not really. When you run batteries like this you double the voltage not capacity. So one 123 and 2X L91's is pretty much the same capacity

Yes but each l91 has a capacity of 3000mAh while cr123 generally only have 1500-1600mAh so about twice the runtime for the two l91's.

 

[Owen]

2 lithium AA will have 2-2.5x the capacity of a single CR123A.

 

[thermal guy]

Yes your right but you also have draw difference and internal capacity/resistance and all that maths stuff to consider

 

[jd101]

So … the actual real-world runtimes will be the same for the two MDCs?

 

[340pd]

The Malkoff website lists the runtime as the same. The CR 123 is substantially smaller and that is the why I went with that model. Unless you are planning on using it at full power all the time, runtime is not really a problem. Lithium 123 batteries are easy to find and they have a very long shelf life.

 

[Owen]

So … the actual real-world runtimes will be the same for the two MDCs?

No.
A L91 is 3300-3500mAh, while a typical CR123A is 1400-1500mAh.
2xL91 will have higher voltage, and over double the capacity/runtime, of a single CR123A.

 

[thermal guy]

I'm thinking if genes 2XAA had double the runtime of his single 123 model he would list that. Im thinking the draw will be different from 2-1.5 volt cells then a primary 3 volt Primary. This is a good question for gene to answer I guess.

 

[jd101]

I did ask. He responded that he may have tested the 2AA with Alkalines and "that may account for the discrepancy." To be honest I didn't fully understand his response; is he implying that the runtime would be greater with the 2AA lithiums?

Also I'm mostly anticipating use at the medium setting so there is plenty of runtime with either option, right?

 

[Coulomb.]

Best way to find out is run a test and see for yourself. Alkaline AAs will not perform as well as lithium metal AAs.

It is my view that CR123a are obsolescent. There will always be AA cells around and you have a choice of chemistries. The lithium-metal chemistries (used in CR123a and AA cells) do have a long shelf life and are compact...but... I have become a fan of the higher quality low-self-drain NiMH cells, Eneloop and similar. These also have a long useful shelf life in standby applications plus are rechargeable and have enough capacity for most situations.

Surefire popularized the CR123a for flashlights during the incandescent era when the score to beat was a maglite with three D cells. Lights built around two CR123as could provide comparable output in a radically smaller light albeit at the expense of runtime. Now that we have LEDs I don't see the relevance

 

[Showngo]

I don't know about runtime, but there's a large size difference in the two lights, and the CR123 (16340) form factor is often the ideal size for a light you want to have a good grip on, while still being able to carry in your pocket. The MDC CR123 is one of my favorite lights I own for this very reason. It's an absolutely perfect size, and I have yet to see issues getting a CR123 to show up at my house, and it's easy to carry a backup in your briefcase.

But if you do go AA, I agree that Eneloop or similar is for sure the way to go. They are great, but they also don't run the risk of corrosion.

If you head over to Prometheus Lights (darksucks.com) he sells silicone tail caps, there is a glow in the dark model which is perfect in the MDC for the nightstand. Unless your eyes work better in the dark than mine do. No sense having a light near the bed if you can't find it when you need it.

 

[jd101]

I don't disagree. I have plenty of 123's on hand for my G2L, and now use lithium AAA on my -new- Prometheus Beta QR which I had to buy recently after destroying my old one from alkaline leakage (which surprised me because I hadn't remembered putting an alkaline in there at all, oh well). I used to keep a 123 HDS42 in my briefcase but it had some issues and was retired. Battery availability is not an issue where I'm located and I'll probably get the 123 for the form factor if I'm not giving up anything, which from the above I think I won't be.

 

[Owen]

Guys, I highly recommend the Keeppower USB-rechargeable 3.0V RCR123 and 1.5V 14500/AA(make sure you get the newer version with 2260mAh) for the MDC lights.
Their biggest shortcoming is the voltage-based "regulation", which means that output varies with voltage. That means it drops steadily(in all 3 levels) with lithium, alkaline, and NiMh alike as the battery is depleted.
The 3V RCR123 is noticeably longer than a CR123A, but is fine for the MDC 123, because it has springs at the head and tailswitch.
The AA/14500 doesn't appear to have that problem with additional length.

Because these batteries put out a constant voltage, they effectively give the MDC lights the current regulation they lack, so that output remains the same throughout the battery life.

Here are the current draws and runtimes you should expect from the 860mAh 3V RCR123, based on my MDC HA CR123:
Hi 1070mA 47min 38s(that's 847mAh actual, 98.4% of rated capacity)
Med 230mA ~3.7hrs
Low 40mA ~21hrs

Medium and low *may* get more runtime due to their lower current demands, but I have not tested them.

Assuming similar performance from the 1.5V AA version of the batteries(voltage, and therefore current draw, should be identical)...2260mAh ÷ 860mAh = 2.63x the runtime for 2 of them vs. the single RCR123.

If any of those runtimes appear lower than other battery types, keep in mind that these will maintain max brightness the entire time, while the primary CR123A's runtime graph looks like this:

So on High, we're talking about tripling the full output runtime at the expense of that long taper.

These constant voltage Keeppowers transform the MDC 123 series into completely different lights, with the only downside being that they are protected, so will shut off when the battery is depleted with no dimming/tapering to warn you.

 

[michaex]

This graphs by @HKJ should explain everything - notice the capacity difference between alkaline, lithium and nimh.

 

[thermal guy]

Yes see. It's the maths that explained It. Can't go wrong either way really.

 

[Cree XHP 70 LED]

I chose the 123A model in SHO (Single High Output) to use up my partially used SF123A cells that come out of my Surefire PX2, PX3, and Elzetta Charlie lights. While some newer lights use rechargeable cells, I don't think 123A cells are going anywhere soon, like in the next 30 years easy. If anything they are becoming more common.

Infact, last week while standing in line at Walmart I saw they are now selling 2 packs and 12 packs of 123A's at the checkout counter now. 12 Energizer 123A cells in a blister pack was $28.99. Or a 2 pack for $8.99. Target has them cheaper, but you can get 12 SF123A cells for $25 which will last you a very long time in that light.

I use rechargeable cells too, but I like my light to be able to also accept SF123A cells too just incase.

To answer your question directly, the size of the 123A light is my personal preference. Don't worry you will get the AA light too.