Leaking Eneloops

[louie]

Contrary to popular belief, I seem to have some AAA Eneloop leakers.
Some discoloration is seen around the anode, under the wrapper, and some white-green crystaline gunk around the cathode. Taking off the wrapper, there is rust around the anode fiber ring, and it looks to me like the electrolyte has wicked down the wrapper. The cells still seem to work, but I'm discarding them. These were used indoors (TV remotes, I recall), and charged periodically with a Maha MH9000 at 500mA. I don't keep records of all dates, but the embossed code says 06-06 0K.

Construction unlike Kirkland alkalines, where the entire shell is the anode and the cathode has the seal. I wonder if this design difference contributes to alkalines leaking so badly nowadays?

 

[StagMoose]

Well that is interesting. Guess after a while they can leak. What is the status of the remote it was in? Any visible corrosion?

 

[fmc1]

That's disappointing to say the least. Thank you for sharing.


I have bought well over a hundred Eneloops over the years and never saw one leak. Some of mine were used under some harsh conditions like outdoors for years at a time. To see one leak in a TV remote indoors has me at a loss for explanation.


What is your confidence level that the Eneloops are genuine and not fakes?


Frank

 

[xxo]

Had a AAA eneloop leak a drop of rust colored liquid after it was over discharged. They can also vent electrolyte when they are over charged but with eneloop's jelly roll construction, the amount of liquid electrolyte inside is very small.

 

[Lynx_Arc]

Nimh can leak, I've a lot of older nimh that have leaked but did no damage the leakage tends to be a lot less of a problem than alkaleaks cause. When nimh get older sometimes they develop higher internal resistance which can cause chargers issues that can lead to cooking the batteries when they overcharge them somewhat as it takes a lot more voltage for them to be seen as terminating by the charger.

 

[louie]

What is your confidence level that the Eneloops are genuine and not fakes?

Confidence is high; l don't buy eBay and I think these came from Thomas Distributing. Look like maybe from 2006.

 

[SKV89]

I just had a AA eneloop leak few weeks ago while charging. I heard a pop sound and checked out the charger that's when I saw it. It was smoking. I immediately unplugged the charger.

 

[WalkIntoTheLight]

Confidence is high; l don't buy eBay and I think these came from Thomas Distributing. Look like maybe from 2006.

That's when Eneloops were originally released. I have 8 from that year. Still use them. I've pretty-much worn out 4 of them, but they're still good for low-drain stuff like remotes or clocks. I still use the other 4 in flashlights, and they work fine. Higher internal resistance than new Eneloops, but not so much yet that they're worn out.

 

[HarryN]

14 year old batteries that are still in use?

My interpretation of this graph is to toss them after 200 - 250 cycles.

http://aacycler.com/battery/aa/panasonic-eneloop/

 

[louie]

Well that is interesting. Guess after a while they can leak. What is the status of the remote it was in? Any visible corrosion?

Leakage seemed so minimal that there was no damage to the contacts on the remote. Just the fuzz on the battery. I swabbed the contacts with alcohol. Whatever leaked seems much less aggressive than alkaline leakage.

 

[WalkIntoTheLight]

14 year old batteries that are still in use?

My interpretation of this graph is to toss them after 200 - 250 cycles.

http://aacycler.com/battery/aa/panasonic-eneloop/

That really depends. AA Cycler uses pretty harsh tests, compared to general use. They're also full cycles. After a few hundred cycles, the IR may be too high, but the batteries still have plenty of capacity when used in low-drain devices.

14 years is a long time, but most of my batteries don't get a lot of cycles. Some are charged daily (those are the ones I wear out), but others may only be charged every few months or longer.

The worn-out ones still maintain their low self discharge, so they're still good in clocks and remotes.

I have some NiMH batteries over 20 years old (obviously not Eneloops), and they still work. Their IR are too high for flashlights, but they're okay for solar garden lights and stuff like that.

I expect Eneloops will last longer than 20 years, but probably not be much good in high-power flashlights by then. Age is going to deteriorate them eventually, even if they don't have a lot of cycles.

 

[Timothybil]

I had the same thing happen to one of my AAA NiMH, except it left some crystaline gunk on the walls of my light body. What is the beset way to clean that up? I was going to use my Dremel on it, but I can't find a sanding drum small enough to fit inside, and I haven't figured out how to make it reach way up to the front. The light is a Sofirn C01, which was only around $10, and they aren't available any more.

 

[Marc999]

Here's an 8-10+ year old AAA Nimh - Duracell Rechargeable. I think it was one of those rebranded black tops, if that's of interest.

 

[louie]

I had the same thing happen to one of my AAA NiMH, except it left some crystaline gunk on the walls of my light body. What is the beset way to clean that up? I was going to use my Dremel on it, but I can't find a sanding drum small enough to fit inside, and I haven't figured out how to make it reach way up to the front. The light is a Sofirn C01, which was only around $10, and they aren't available any more.

Is the gunk crystalized electrolyte, or corroded metal (I assume aluminum)? Anodized?

Personally, I'd first try to remove any electrolyte with plenty of water, spray cleaner (like 409) and alcohol. You may have a problem if the electronics can't be isolated. If you have to polish out corrosion, I would tape some fine sandpaper to a pencil or the like, and do it by hand, or low speed drill motor. I would think a Dremel would be too fast.

 

[louie]

Here's an 8-10+ year old AAA Nimh - Duracell Rechargeable. I think it was one of those rebranded black tops, if that's of interest.

I don't see the photo?

 

[BVH]

I've posted this before but will again. I bought 156 AA Eneloops in the latter part of 2010 for electric blinds. All are still performing well. Not a single failure.

 

[louie]

I have several dozen AA Eneloops through the past decade or so and they are all fine, too.

 

[Rickajho]

I bought on of those 8 AA 4 AAA BQ-CC55A charger kits on Amazon in April. I put one of the AAA batteries in a thermometer/hygrometer on 05/02 with just the pre-charge it came with. (Only uses 1 battery.)

Today the thermometer display was dead. Opened it up to find a... leaking AAA eneloop! The negative terminal has dried on black goo, so does the spring in the thermometer, and there is yellow-brown sludge in the battery well.

What's weird - heh - in this case is the wrapper isn't discolored and the positive terminal looks fine. Haven't ripped the wrapper off yet, pending contact with Amazon.

It's also testing at 1.3 volts.

 

[AstroTurf]

I bought on of those 8 AA 4 AAA BQ-CC55A charger kits on Amazon in April. I put one of the AAA batteries in a thermometer/hygrometer on 05/02 with just the pre-charge it came with. (Only uses 1 battery.)

Today the thermometer display was dead. Opened it up to find a... leaking AAA eneloop! The negative terminal has dried on black goo, so does the spring in the thermometer, and there is yellow-brown sludge in the battery well.

What's weird - heh - in this case is the wrapper isn't discolored and the positive terminal looks fine. Haven't ripped the wrapper off yet, pending contact with Amazon.

It's also testing at 1.3 volts.

recharge and reinsert...

 

[Rickajho]

recharge and reinsert...

Yer kidding right?

The spring is so mucked up it can't make proper contact with any battery. Already tried.

Will be speaking directly with Panasonic tomorrow. At least that's what Amazon said.