9v Batteries

Self discharge for the Energizer LiFeS2 batteries is 20 years. Top that with *any* Ni chemistry.

Where did you find that number? I've been Googling for 15 minutes and not been able to find any self discharge specs or tests. This is as close as I could find, and it too doesn't specify down to what charge level the cell was tested (usually 80% of full charge):

The section on LiFeS2 says: "Lithium-iron", "Li/Fe". Called "voltage-compatible" lithium, because it can work as a replacement for alkaline batteries with its 1.5 V nominal voltage. As such, Energizer lithium cells of AA and AAA size employ this chemistry. 2.5 times higher lifetime for high current discharge regime than alkaline batteries, better storage life due to lower self-discharge, 10-20 years storage time. FeS2 is cheap. Cathode often designed as a paste of iron sulfide powder mixed with powdered graphite. Variant is Li-CuFeS2.

L91 and L92 Data Sheet:

What does Elevated Self-discharge Do? Note that abusing LiIon cells by deep discharge and shorting the terminals increases self discharge.

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Jeff Liebermann     jeffl@cruzio.com 
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I can't cite a reference, but I read it on the internet, so it must be true. Standard alkaline batteries have a stated shelf-life if you never put a load on them. Once presented with a load, further shelf life can decrease dramatically.

I have had the odd one go bad. Usually left in something for too long.

At least in the UK I have found that Kodak's cheapest nastiest batteries survive in high current drain applications where Duracells have leaked on me. EveryReady & Panasonic also seem to be OK at least in the UK.

I won't use Duracell any more. I can't tell if it is a problem with high quality counterfeit or their actual genuine manufacture batteries. There was a time in the past when they were the copper topped gold standard!

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Regards, 
Martin Brown

Everyone lies. But, that's ok because nobody listens. My usual excuse is that I can't offer a reference because I'm too busy or lazy to Google for one.

"Mercury in Batteries" Prior to about 1996, alkaline batteries contained a small amount of mercury. That's what kept alkalines and others from leaking by outgassing. At about the same time, the expiration time (shelf life) was shortened for alkalines. Where to find the date: This is different from self discharge rate as some of the leaky batteries that I've tested seemed to be just fine. (I should have run a discharge test on some for verification). For example, I had an incandescent flashlight that had leaky D size Duracell alkaline cells, that was quite bright for about 30 minutes.

Also, some of these worked fairly normally, even though they leaked:

Agreed. A battery that is never used will theoretically last forever.

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Jeff Liebermann     jeffl@cruzio.com 
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Boom when shorted, probably because the gas vent plug was either defective or missing. I didn't do the test or take the photos, so I wasn't able to determine if they were real Duracell Procell or counterfeit.

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Jeff Liebermann     jeffl@cruzio.com 
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Skype: JeffLiebermann     AE6KS    831-336-2558

The Energizer L92 datasheet, IIRC. I don't have it at home, though.

That's not a datasheet. It's a product blurb, maybe.

Not surprising but LiFeS2 LiIon.

That's my experience, as well. Whenever I use one of my "emergency" flashlights, I pitch the batteries and put in fresh ones.

Not according to any theory I'm aware of. There's inevitably some way for stuff to diffuse around and decrease the stock of stored energy.

Some lithium cells are touted as having a twenty year shelf life (if stored below 20C), and the lithium coin cell that powers my watch does roughly seven year under load.

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Bill Sloman, Sydney

If a tree falls in a forest and no one is around to hear it, does it make a sound? The unused battery is much the same. If nobody uses or test the battery, how does one know if it's charged or dead?

Lithium thionyl chloride (LiSOCl2). They're up to 40 years now: The major technology improvements come various ways to reduce self discharge. If progress continues at the present rate of improvement, we may eventually have a battery that will last longer than an average human lifetime.

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Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Polluter. What do you do when someone else uses one of your "emergency" flashlights, and doesn't tell you that they used it? Do you just assume that it will work when needed? With mission critical hardware, such as UPS (uninterruptible power supply) batteries, the batteries are replaced by a regular schedule, regardless of whether they were used or not. That's how I sometimes get big UPS batteries with about 50% of the life left in the batteries for free. Sometimes, it includes the UPS. If you persist in using non-rechargeable batteries, what you should be doing is buying a new "emergency" flashlight every 6 months or so, and donating the old flashlight to suitable charity. That should save you the trouble of recharging batteries on a regular schedule, monitoring capacity, or measuring the SoC (state of charge).

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Sorry. I missed the real datasheet on my initial search. This should be it for L92 AAA and L91 AA. They both say:

but don't bother to specify the conditions when the battery is considered no longer suitable for sale or use. My guess(tm) is 80% of full charge, but I haven't found that stated in any of the Energizer literature.

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Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
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Skype: JeffLiebermann     AE6KS    831-336-2558

Incidentally, the shelf life for an Energizer L91 AA *alkaline* cell is claimed at 10 years @21C: None of the alkaline cells I've bought have lasted that long and usually leak in the box or in the instrument long before 10 years has passed.

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Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

...and proud of it!

There are only two of us in the house. No one else drives our vehicles. We have other "day to day" flashlights. That's not a real problem.

I do it so the batteries don't leak, not so much that it's fully charged when I need it.

UPS batteries are rechargeable. Totally different animal.

Utter nonsense.

You asked where I got my "20 year shelf-life" number. Now you have it.

IME, they don't leak unless they're used. I've never seen one leak in its packaging.

snipped-for-privacy@notreal.com wrote in news: snipped-for-privacy@4ax.com:

It is a galvanic thing. They do age in perfectly appearing normal condition. Those simply avalanche to an uncharged state quicker is all.

Rechargeables can be recharged with a hand crank charger. Far better for a survival set up.

I beg to differ: The right bubble pack was NOT opened which means the cells were not used prior to them deciding to self destruct. The left was opened. Assuming you trust me, the left cells had not been used. I've had Costco Duracell AA cells do much the same thing in the original bubble packaging.

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Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Ok. However, I find it rather odd that I should supply the source of YOUR information. In the future, it would be helpful if you would provide your own sources and corroborating information.

I still haven't found anything to indicate the condition of a cell that has spent 20 years on the shelf in a box. More simply, if I sold you a 20 year old cell, what condition would YOU expect it to be? Is

80% good enough? Or is some other number considered acceptable? Personally, I like my primary cells as close to 100% as possible, and would not consider buying a 20 year old cell unless the manufacturer also offers a 20 year warranty.

I was at Safeway market today and looked at the Energizer L91 AA cells in stock. Expiration date EX 12/2037. Assuming it was made in 2017, that's 20 years. I asked the manager if they planned to keep them on the shelf until 2037. Nope. They return them to their supplier after

5 years when they are considered unsellable.

Thanks for the suggestion but I'll stick with rechargeable cells. They can be topped off. They can be tested for capacity. They can be non-destructively characterized with a discharge tester. I can't do any of these with a non-rechargeable cell such as LiFeS2.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558