Do Li-ion batteries expand with age?

[jitter]

Some years ago I bought a Nikon P500 camera with some extra batteries. The extra batteries were no name replacements for the Nikon EN-EL5.

I just noticed that it seems like at least one of the replacements has expanded a little. It still works fine, but especially removing it from the camera isn't easy, it binds slightly on the inside of the battery compartment. The original doesn't do this and I'm pretty sure that it wasn't always a problem with the replacements either.

Is this a known symptom for LiOn batteries that age?

[MK14]

That's (I think) a rather BAD sign. That the cell(s) of the battery are beginning to fail/deteriorate and may dramatically fail (e.g. fire hazard) at some point.

I had a similar thing, where a stored (unused) LiPoly battery (set), started expanding. But it was in a clear plastic case, so I could see that the bulging battery was because it was badly deteriorating.

Although I knew it was probably madness to even try the battery, I asked another electronics guy and he said "Don't be crazy, bin it".

So I carefully made the cell(s) safe and disposed of them shortly after that event. Because I did not want to risk a fire or something.

EDIT:

[helius]

While hydrogen gas buildup is often a sign of an abused or depleted cell, in some cases the chemicals are still in good shape and will work as normal. Venting the hydrogen is a risky procedure and should only be attempted in a dry inert atmosphere.

Hydrogen is released from almost all battery types, not just LiIon. LiIon and LiPoly types are different by having no vent: because they must always stay dry (Lithium and water react) there is no way to shed the excess hydrogen and so they bulge.

[rich]

LiFePo4 (Lithium Iron Phosphate) batteries are much more stable. They don't combust when abused during charge/discharge. I haven't tested one to destruction myself but I trust them enough to replace the lead-acid starter battery on my car with a pack. They only have about half the energy density as LiPo though.

[CatalinaWOW]

While there is some danger of a catastrophic failure, I personally wouldn't worry too much about that.  I would retire that battery for two other reasons.  First, while you say it works fine, my experience has been that batteries that have released enough hydrogen to bulge noticeably have lost significant capacity.  Missing a critical picture because the battery has gone flat unexpectedly is enough reason by itself to bin the battery.  Second, the batteries cost much less than the camera.  The chance that it will swell enough to make it impossible to remove from the camera without damage just doesn't seem like the right economic trade to me.

[amyk]

Yes, bad or abused ones do:



A swollen one will have much lower capacity since the plates have been forced apart by the buildup of gas inside.

[Siwastaja]

A slight bulge is normal and acceptable, but too much is a sign of either cell abuse, cell quality problem, or end of the lifetime. Sorry I can't be more specific what is "slight" and what is too much. It's best to replace the battery ASAP if the cell is swollen enough that it doesn't fit where it should, or it looks clearly "wrong".

This is called "gassing" and it's not simply just hydrogen, but a mixture of gasses, some (volatile decomposition products of the organic electrolyte) indeed flammable. It's not usually a huge safety concern as is, but the risk is always there. More about the gasses (found by simply Googling): https://www.researchgate.net/publication/273120215_Insight_into_the_Gassing_Problem_of_Li-ion_Battery

rich,
my (limited) experience shows that real production LiFePO4 cells have more severe gassing problem than industry-leading LCO, NCA or NCM products. Also, they have wrong voltage to be considered here (but do have the right voltage to be used as a 12V lead acid replacement).

[jitter]

A slight bulge is normal and acceptable, but too much is a sign of either cell abuse, cell quality problem, or end of the lifetime. Sorry I can't be more specific what is "slight" and what is too much. It's best to replace the battery ASAP if the cell is swollen enough that it doesn't fit where it should, or it looks clearly "wrong".
have the right voltage to be used as a 12V lead acid replacement).

Time to bump up this thread as the holidays are coming and I need a dependable camera!

Thanks for you answer.
Yes, the two unbranded EN-EL5 clones have a slight bulge to them that the original Nikon doesn't have. One of them seems a bit worse than the other, so I decided to discharge them and post the results here, see what you think.

The original EN-EL5 is rated at 1100 mAh and 4.1 Wh, the generic ones don't specify capacity at all, but I'm going to assume they're similar.

The first one has just finished a discharge cycle down to 2.7 V right after having been fully charged. At a discharge current of 250 mA, it gives about 740 mAh. The attachment shows what the curve looks like.
That's more than I expected as the camera seems to go through a charge on this battery rather quickly.

Right now the second generic one is in the process of being discharged, and then I'll do the same to the original to have a benchmark. I really don't know what to expect with 4-5 year old Lion batteries.

[mikerj]

IME most of the generic clone batteries of cameras etc. are lower capacity than the originals, even if the capacity printed on the side is the same. 

Your finding closely mirror the results I found on some clone batteries I bought for my Canon pocket camera a while back.  They measure around 850mAh compared to the 1100mAh of the original, though are claimed to be 1100mAh cells.

[jitter]

Second one done, this turned out to be just shy of 720 mAh.
Now I have the original Nikon on it that came with the camera. The generics were bought pretty shortly after I bought the camera, so they must be about the same age.

IME most of the generic clone batteries of cameras etc. are lower capacity than the originals, even if the capacity printed on the side is the same. 

I'm really curious what the original that is rated at 1100 mAh will do. In about 3-4 hours I'll know.

Your finding closely mirror the results I found on some clone batteries I bought for my Canon pocket camera a while back.  They measure around 850mAh compared to the 1100mAh of the original, though are claimed to be 1100mAh cells.

I kind of expected that to be the case. Most replacement brands seem to quote around the 1000-1200 mAh mark when sold through a local webshop. But, of course, Chinese websites like to exaggerate a bit. How about this one that they say is a DSTE EN-EL5 Full-Decoded 1700mAh Battery for Nikon COOLPIX 3700,4200. A fully decoded battery ...  That's Chinglish for.... 

[Kilrah]

One thing that is often a characteristic of low quality Chinese batteries is high internal resistance, so even if they have decent capacity it's at a voltage that may cause the camera to shut down during current bursts. Your 250mA are conservative, you should probably discharge at 500mA-1A to see how they behave in that case.

YMMV (a lot) with replacement batteries. Over the years I've had some that were pretty OK but visibly less good, some so hopeless that after buying 3 different "replacement" brands I had no choice but to throw them out and buy originals. I've also had some that impressively still worked acceptably after >5 years, when the originals were long dead...
My current camera uses Sony NP-FW50s, I've got 2 originals and 2 very cheap replacements and they just work, I simply can't tell them apart without looking at them.

[jitter]

It took a bit longer for the Nikon to drain, so I when I went to bed, it was still going. At the point where the generics had been depleted, the Nikon was still only just below its nominal voltage.
The discharge curve also looks quite different, much flatter and with a much sharper drop at the end. Total capacity ended up being almost 1170 mAh (@ 250 mA discharge current). More than stated on the battery, but I don't know at which discharge current that was determined.

Lately the replacements felt like they drained rather quickly compared to the Nikon. Not only the lower capacity is to blame, also the much less flat discharge curve probably makes the camera switch off long before that capacity has been used up.

One thing that is often a characteristic of low quality Chinese batteries is high internal resistance, so even if they have decent capacity it's at a voltage that may cause the camera to shut down during current bursts. Your 250mA are conservative, you should probably discharge at 500mA-1A to see how they behave in that case.

YMMV (a lot) with replacement batteries. Over the years I've had some that were pretty OK but visibly less good, some so hopeless that after buying 3 different "replacement" brands I had no choice but to throw them out and buy originals. I've also had some that impressively still worked acceptably after >5 years, when the originals were long dead...
My current camera uses Sony NP-FW50s, I've got 2 originals and 2 very cheap replacements and they just work, I simply can't tell them apart without looking at them.

Thanks for your insights.
I'm still deciding on buying a new original (€ 40) or again a replacement (€ 10-20), but one thing is clear: the bulged generic replacements are going to go.
I think even at 250 mA, which I had arbitrarily chosen,  the no name replacements are clearly no match for the original. I will repeat the discharge cycle at 500 mA for all three batteries, but I think the steeper discharge curves of the generics already indicate a higher internal resistance.

[jitter]

Finished doing the discharges at 500 mA.
The no name batteries have gone down even further in capacity, while the Nikon still does better than specified.

Brand	Capacity @ 250 mA	Capacity @ 500 mA
Generic 1	740 mAh	680 mAH
Generic 2	720 mAh	550 mAH
Nikon	1170 mAh	1150 mAH

I'll buy an original.

[Audioguru]

Cheap Chinese Lithium (and "super heavy duty") batteries are poor quality. You pay for the boat that gets it here, not for the battery.
1) Here is a graph of the voltage from model airplane Li-Po batteries. The bad ones are cheap and are Chinese.
2) Here is a video of what was found inside a cheap Chinese Li-Ion battery.

[jitter]

Since I'm going to discard the two generic EN-EL5s anyway I thought maybe I can have some fun with them.

The first one I drained at a current of 1 A to find that the capacity then is hardly better than 520 mAh. Then I put 2 A across the terminals to see if the circuitry would protect against over discharge. It does but not until the voltage has gone down to a bout 2.1-2.2 V, which seems rather low.

I split open the plastic case and found the type of the cell: FT603048A. I can't find the exact same type, googling finds some polymer cells of the same size, but they look different.

[jitter]

Conclusion:
I'd like to conclude this thread with the the 1 A discharge curve of the second generic EN-EL5. It was always performing a bit less, but it really didn't stand up to the 1 A discharge at all, dropping to an unusable voltage almost immediately and struggling to reach a paltry 200 mAh. This one tested to 2.25 V before the protection circuitry killed the discharge, so at leat they're protected.

I hadn't told it in this thread yet, but I got the camera with one original and a different generic EN-EL5 that was part of a kit. This one did have a rating of 1200 mAh on it.
That one started to refuse to hold a charge several months ago. It was so bad I didn't even test it. It had not bulged, though, like these two had.

The two I was talking about in this thread (with the black label) were of a subsequent buy. At the time the camera felt like it was using up way too much energy for such a small battery, and I wanted to be better safe than sorry.
With hindsight I could have done fine with buying just one extra original for the seemingly over the top price. But in the end, it would have worked out cheaper.

Tip:
There have been quite a few models of Nikon cameras over the years that use the EN-EL5 (the manual that came with the new EN-EL5 was copyrighted in 2003). If you're in the market for a spare battery, but don't want to shell out on what the original costs, buy a brand that you know is reputable for selling good quality replacements. Or at least avoid those in the attachment, IMHO they turned out to be not worth their money.

[SeanB]

Funny enough I have a bulging BL-4C that was in my dashcam for a while. Started bulging and also lost so much capacity that the camera did not shut down properly on power off. Pop in a new one and all fine again. Now just have to go to the cell shop and get some new clones.

[jitter]

I elected to go for an original given that five years after buying this camera (June 2011) the battery still performs better than specified. That won me over, despite the price.
The new battery came in the mail today and I put them side by side. There are only the slight differences between production batches, and one small Nikon logo has been replaced with that of (presumably) the OEM: Maxell.