L91 failure rate / fragility

I very much appreciate a primary alternative to alkalines. I also appreciate lithium primaries' cold weather performance and long shelf life.

Unfortunately, I have had a high failure rate with Energizer Ultimate Lithium L91 AAs over several years from several packages; this tells me that it can't be that I got a bad batch once. In my experience lithium AAs have been fragile and inconsistent in quality. This is disappointing to me because so much of their appeal is that they're supposed to be so reliable and ready to go.

For those who use primary lithium AAs and AAAs, what has your experience been?

I've had great results in performance and reliability with them in AA and AAA so far, however I've only ran maybe a dozen or so of each. Those that I have rather have survived 140F to -20F without any complaint though

What do you mean by failures? DOA? Or short runtime? I have used them for years probably 200 -300 or so and can't recall having a single problem.

I've used countless ultimate lithium. Can you elaborate on what kind of problems you've had because I've experienced zero in several years of use.

thermal guy said:

What do you mean by failures? DOA? Or short runtime? I have used them for years probably 200 -300 or so and can't recall having a single problem.

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Started my reply and didn't finish as soon as you but I'll just say..... jinx. Never a problem

I have been using them for years without a single failure, so I am really surprised-could you explain what you mean by failure? Is it possible you are using them in lights with high parasitic drain that could lead to premature depletion? I had many failures with the early Energizer rechargeables, but the performance of the L91 has been impeccable. I have used them in both hi temp(deserts) and cold weather too. Please share what lights you are using them in too. Anyone else having any problems with them?

A lot of smart minds thinking alike. 😄😁

Thetasigma, thermal guy, Bigburly, Crazyeddie, thanks for the responses. Between the four of you we have a sample size of hundreds of cells spanning several years with no failures; this confirms that I have had a string of coincidental outlier experiences.

That is exactly the information that I was looking for!

Over the 3+ years that I have been using dozens of L91s and L92s I have had a few that were DOA and quite a few that gave up suddenly under normal use - meaning that a multi-cell light would suddenly go dim and when I'd check the voltage on the individual cells one of them would be dead while the other(s) were fine. Recently I dropped a cell while loading a 2xAA light; that light went dim perhaps 15 minutes later with one dead cell and one still reading full voltage, leading me to presume that the dead cell was dead because I dropped it...

Anyway, my mind is put to rest that the L91 line is fine, and I just need to be more careful in my handling of cells and diligent about checking voltages right out of the package.

Thanks again!

No problems for me with these.

Actually I've been really impressed overall with the performance (especially in the cold) and very light weight.

I haven't done any formal testing, but they seem to last very well in "intermittent use" situations, when they may sit idle for long periods.

It would be nice if they weren't quite as expensive, but quality costs ... :shrug:

Do your cells regularly see "hard knocks" (drops and falls, physical damage, or similar) ?

One thing that is a little different about these, compared to alkaline primaries, is that they have a rather "flat" discharge curve.

While alkalines typically have a long slow taper as they drain, these tend to consistently deliver nearly all of their energy but then suddenly "crash" to empty.

archimedes said:

No problems for me with these.

Actually I've been really impressed overall with the performance (especially in the cold) and very light weight.

I haven't done any formal testing, but they seem to last very well in "intermittent use" situations, when they may sit idle for long periods.

It would be nice if they weren't quite as expensive, but quality costs ... :shrug:

Do your cells regularly see "hard knocks" (drops and falls, physical damage, or similar) ?

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Thank you, archimedes, I really appreciate your response.

My cells have always been purchased in bulk from a warehouse store so I suspect that they are not treated 'appropriately' before I get them. Once I have them they are handled gently - unless I drop one! Which does happen. The one that recently failed suddenly was dropped onto a concrete floor, so could certainly explain that failure - it would be nice if such an expensive cell could handle a such a drop, but as you say quality costs and I wouldn't want to give up any of the cells' other qualities (temp range, performance, lightweight, shelf life, capacity and so on) just so that I could drop them with impunity. (Attempting word play here, don't know how well it'll come across)

archimedes said:

One thing that is a little different about these, compared to alkaline primaries, is that they have a rather "flat" discharge curve.

While alkalines typically have a long slow taper as they drain, these tend to consistently deliver nearly all of their energy but then suddenly "crash" to empty.

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I was recently running a 3-cell incandescent on 3xL91. I ran the light until the bulb went very very dim. Reading the cells afterward showed that one was gone and the other two were relatively even with each other, much higher than the flat cell.

I knew of the discharge characteristics of these cells, but it wasn't until reading your post that it really clicked that that was what is happening - the "failed" cell simply was that tiny bit further along the discharge curve and thus crashed completely, while the other two were much closer behind than I originally thought.

This is great getting this stuff figured out! The collective information here is really bringing things together. My signature holds true, ha ha!

One thing I noticed is L91s measure 1.8v or so when new and about 1.6v when depleted so measuring the voltage keeping that in mind gives you an idea of the condition of cells. It is easy to believe at 1.6v it should have plenty of power left but that isn't the case at all.
Under a load the batteries measure differently depending on the load.

As I read your response one thought did occur-is it possible you are getting counterfeit cells? As a random control experiment, try purchasing a pack in person in retail packaging. Try them in one light that you used the other cells in and see if there is any difference. I have dropped both the batteries and also lights with batteries in them and never once had one fail( some of my lights have climbed some very difficult terrain with me-I once had light(Sunwayman D40, 4 AA, fall 30 feet and other than dents and scratches kept working fine). The whole reason I bring up counterfeit cells is that the Lithium Ion rechargeable cells have been copied so many different times and ways a lot of us have had an experience with it. That is why 95% of CPF'rs will suggest only buying brand name cells from a reputable seller. I have not heard of L91/L92 fakes, but it would not surprise me-I hope I am wrong on this...

[

Well, my 2013 batch of Energizer AAA Ultimate Lithium batteries, which the factory guaranteed "Not to Leak", leaked!

I've had "meh" results from Energizer Lithium AA's. I haven't used very many, but the few I have used died after about a year in storage. However, my "storage" was keeping them in the car all year. I presume the extremes of cold (-25C in the winter) and heat ( ??? in the summer sun) led to premature death. I got them hoping they would stand up to that kind of abusive storage, but perhaps they're not that tough. Regular Eneloops seems to fare better in that abuse, as long as I charge them once or twice a year. Well, the internal resistance probably takes a hit, but they can at least still power lights. Even alkaleaks do okay in the car. Maybe my Energizer Lithiums were just unlucky (all 4 of them, IIRC).

Glad to see some more from the other side. Hoping more people chime in with failures as I've never had any of any kind. Interesting to get both angles

Bigburly912 said:

Glad to see some more from the other side. Hoping more people chime in with failures as I've never had any of any kind. Interesting to get both angles

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Yes, this kind of info is most helpful, and what forums like ours are all about.

Those leaking cells seem really odd, are there any more details about that ? Storage conditions ? In use or not ? Source of cells ? etc ....

As we all know, for the typical ( > 99.99% ) consumer, batteries are basically a blank metal can with a printed wrapper that one hopes is "correct"

archimedes said:

It would be nice if they weren't quite as expensive, but quality costs ... :shrug:

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Yes, but right now I am seeing them at our favorite online retailer for $1/cell. Still a lot more than the $0.25/cell one can find, but worth the difference for the guaranteed no leaks.

Timothybil said:

Yes, but right now I am seeing them at our favorite online retailer for $1/cell. Still a lot more than the $0.25/cell one can find, but worth the difference for the guaranteed no leaks.

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I think the best price I was ever able to find was ~ 85 cents ea (on special) , but that's been quite a while back now