Batteries, Shelf life vs. Activated life...

Cthelite

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I see that the shelf life of alkyline batteries is approximately 7 yrs from when shipped from the factory. But it appears that once the bats have been placed into service (activated) that they loose that life expectancy.

Is this a good observation...? If so, what takes place with a bat once you begin to use it...?

If the shelf life of Lithiums is 10 yrs from shipment, how long, approximately, will they remain with a charge once they have been placed into service (activated)...?

I mean, if one was to average the run time over ten years, this doesn't neccesarily mean that the bats will give service over a ten year period does it...?
 

JohnK

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Good question, I don't have a clue. I also wonder

I look forward to the responses.

I suppose you would have to live a long time to find out definitely.
 

Steelwolf

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There was another thread that hinted at this. It talked about passivation, where a sort of shell builds up around one of the electrodes and prevents further self-discharge. And apparently, you can actually cause the shell to reform, even after you have activated the cell. Something to do with sudden, high current drain for a milli-second.

The thread is here. Milkyspit introduces the topic with a graph about halfway through the thread and links to the original article.

I'm guessing that something similar happens with newer alkalines, but didn't with the older stuff, because the older stuff was rated for only 3 years.
 

Cthelite

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Thanks Steel,

Just last night I went to use my SF-C3 and it was dead. The bats were on the dimming side up to this point. I've noticed this before and was wondering if there was something wrong with the light.

Seems that this may be a phenomenon with Li's....?

If this is the case, I need to make preliminary plans eh...?
Least with a alkyline, they seem to die out on a curve all the way to dead. Li's go to a point and then drop off dead..
 

Doug Owen

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[ QUOTE ]
Steelwolf said:
There was another thread that hinted at this. It talked about passivation, where a sort of shell builds up around one of the electrodes and prevents further self-discharge. And apparently, you can actually cause the shell to reform, even after you have activated the cell. Something to do with sudden, high current drain for a milli-second.

The thread is here. Milkyspit introduces the topic with a graph about halfway through the thread and links to the original article.



[/ QUOTE ]

Yeah, but if you follow the thread, you find the other Doug (Doug S.) pointing out that this is a Lithium effect, but not for the chemistry used for the 123 cells. The answer must lie elsewhere?

FWIW I was unable to find anything to support this in any of the maker's literature (at least not right off), data sheets, application notes and manuals don't mention lifetime being shortened by (partial) service, only temperature. I suspect that some if not all the explanation lies in the nature of the discharge curve of the 123. It is indeed flat (or nearly so relative to alkalines) until you 'fall off the edge'. It's easy to creep up to the edge and not really know where it is. It's also easy for it to fall over after you shut down for thermal as well and chemical reasons since it could have been 'right on the edge'. It goes dark, due in part to the digital nature of the electronic load (rather than hot wire), an alkaline (especially with a bulb) would still be some shade of dim.

Another thought about shelf life, they don't die overnight on the appropriate night (corrected for daylight saving's time of course). It's just that at that point substantial capacity is gone, right? I think there's some insight there, but don't see it right off.......

Doug Owen
 

Doug S

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Like Doug O, I haven't found anything in the literature to support the notion that partial use accelerates storage deterioration at least for the commonly used flashlight relevant chemistries. There are exceptions for some more exotic chemistries such as seawater activated, thermal activated [used in some artillery shells], and zinc-air cells. As a casual observation, alkaline cells in my TV remotes tend to last the life of the TV [though I am not an incessant channel surfer] and I have had lithium batteries in watches last close to 10 years.
 

James S

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There has also been quite a bit of discussion specifically about this strange behavior of 123 cells. They will be working fine, you'll put it away for a while and one in the light will go completely dead.

I've had this happen several times myself. The light will be working fine, perhaps reaching the point where you can tell the batteries are no longer fresh, but definitely still working. Then the next time you pick up the light, maybe an hour later, maybe a week later it will be totally dead. Not even a dim response from the light. If you check the cells you'll find one that has gone completely dead and the others in the light will probably be still OK.

In my lights this only happens in the ones with very high current drain like my P61 modded lamps and such.
 

Cthelite

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[ QUOTE ]
James S said:
In my lights this only happens in the ones with very high current drain like my P61 modded lamps and such.

[/ QUOTE ]

This is answering my anser in a diff post. This is what is happening to my SF 200 lumen light...

Man, I'm really liking this site... Now, on to meters... Hehehehe...
 
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