Talking just batteries AA vs. 123

Talking just battery comparisions, not flashlights, what is the big difference between AAs and 123s.
I know that 123s are 3.0v vs AA at 1.5v, and that AAs are 1 1/3 larger than 123s. But what about battery life? are AAs longer lasting than 123s or do 123s burn out quicker because they are smaller and higher voltage?

Just curious.

The 123-cells have longer shelf life and also perform better in the extreme tempatures (hot/cold) of your environment.

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this_is_nascar said:
The 123-cells have longer shelf life and also perform better in the extreme tempatures (hot/cold) of your environment.


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What about compared to the newer Lithium AA's?

You just have to remember that wattage is how you should compare batteries of different form factor and chemistries like what you're trying to do. The lithium 123a batts are 3v multiplied by about 1400 mA which is 3 X 1.4 = 4.2 Watts or 4200 mW. The NiMH are 1.2V X 2.3 mAH = 2.76 W. Here you can see that the best NiMH, those rated at 2300 mAH, is only 66 percent in wattage that of the smaller, lighter Lithium batts.

You can also figure out how long your Luxeon 1.25 Watts equipped ARCs will perform. Say you use the lithium batts, 4.2 watts multiplied by 0.8 (the efficiency rating of the electronics that regulate power to the Luxeon) gives 3.36 Watts divide by 1.25 Watts per hour gives you 2.688 hours of continuous usage. If you use NiMH AAs, you'd use two, then 2.4V X 2.3AH X 0.8 / 1.25 WH = 3.5 Hours of continuous usage.

How do I know it's 1.25 Watts usage on the Luxeon. Cos on ARC's FAQ pages it says that the current supplied to the Luxeon is 330mA which multiplied by the Vf = 1.25 Watts.

Simple see! /ubbthreads/images/graemlins/smile.gif

Of course, with intermittent usage you'd get more than the calculated hours of usage.

Thanks!
V.

Are there any 123 rechargeables?

@VMamie

Sorry, but I think you misunderstood something here.
How long a battery lasts depends on it's capacity, not on it's wattage.

Your calculation is also slightly false:
"3v multiplied by about 1400 mAh which is 3 X 1.4 = 4.2 Watts or 4200 mW"

Actually it's "3v multiplied by about 1400 mAh = 4200 mWh or 4,2 Wh."

"h" means hours and is multiplied with the current in order to get a capacity. 1400 mAh means that you can get the current of 1400 mA one hour long or 140mA 10 hours long or 70 mA 20 hours long...

Spacemarine,

Thanks for catching the flaws. Warning to all others, my calcs are very roughly done. /ubbthreads/images/graemlins/smile.gif

But still useful I think?

V.

That's comparing disposable 123's with rechargable AA's.

What's the capacity of an alkaline or lithium AA vs a 123?

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Jarhead said:
Are there any 123 rechargeables?

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Read this: http://www.tinwhistler.net/flashlights/123-rechargeables.htm

I have some of the cells mentioned in the article on order and will try them in my Arc4+ whenever I get it! /ubbthreads/images/graemlins/crazy.gif

I agree with Spacemarine - I was also under the impression that mAh figures for most cells are actually extrapolated from lower currents and you are not really going to get 2 amperes for an hour from a 2000mAh cell. I could be wrong...

The ARC FAQ on the LS states that a typical good 123 lithium will run 2 hours; 2xAA alkaline will run 1.5 hours; 2xAA NiMH will run 2.5 hours; and 2xAA lithium 3+ hours, before falling out of regulation. That should give you a good idea of the differences in energy. There are other considerations, like cost of running rechargeable NiMH, cold performance, etc. There are no figures for rechargeable NiMH in the single 123 form factor, but I can guess it won't be more than maybe an hour.

When portability is a priority, I use a 123, and when run cost is priority, I use 2xAA NiMH. I'm getting about 3 hours continuous on Powerex 2000mAh regulated. If I were going on a long hike, I'd probably use AA lithiums.

Due to the chemistry of the various batteries, lithium batteries are able to have a higher energy density for a given size, whereas an alkaline battery doesn't. Plus there is the wonderful fact that at the same time a lithium battery also weighs about 10-15% less than a comparably sized alkaline battery. So basically that is why lithium batteries cost more but at the same time are so wonderful. Lithium batteries are basically pushing the limit as to how much energy can be stored in such a little space. So I hope that's what you were looking for.

AA and 123 actually have the same volume, with the 123 a hair bigger. We had this discussion in the Batteries forum a week or two back.

Thanks for the info. I have a better idea about the differences and see why the 123's will start becoming more popular.

Mx

jarhead, a host of diff sizes nimh are available, but if you are going to stack them to get multiple volts in an 123 size, the energy capacity will plummet.

I think I heard something about proteced Li-Ion 123's that might show up in the future. I think one cpf'er is nagging pila about that.

georget, alkalines really blow when you draw a lot of wattage from them. Their voltage sags, like lead acid batts, and their energy capacity goes south.

According to DougS, the 1.5v lith AA are even better than 123 for sustaining high power. Maybe the best high power primaries?