Eneloop AA: leak? rust?

strange... anyone had similar experience?

here are 2 pics of the Eneloop AA...




The date code... 09-03AV


This is a new from package Eneloop, after a R&A in C9000, I put it in EZAA R2 for a burn-in test... continuous running in low. Took it out for Voltage checking after 20 hours, 1.02V, and was shock to find it leaked/rusted? :shrug:

The EZAA R2 positive contact spring and surrounding area shows no signs of any foreign material, Q-tip (dry and DeOxIT) shows nothing at all (unless there are some microscopic particles ).

This is my third case of rechargeable cell going bad... the first was a Recyko+ AAA cell corroded in a Brother Labeler(at the positive terminal too), second was a China-made Sony CycleEnergyBlue not terminating (after been in C9000 for 4 hours at 1A charging) and temperature goes up >55 degree C. :candle:

A couple of Hybriloops used in an electric toothbrush:



I put it down to the damp environment. I have not seen any other cells do the same thing. Is it humid where you live?

Looks like rust, but who knows for sure.

Some of my eneloops looked like that after using them in an R/C boat.

Mr Happy said:

I put it down to the damp environment. I have not seen any other cells do the same thing. Is it humid where you live?

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yup... our himidity level is >70%...

Maybe somehow a drop of water or sweat hit the battery before you put it in the charger? I would clean it off with a wire brush, and see if it comes back.

I haven't had any LSD nimh leak but I have cooked the insides out of a non LSD nimh and it is white powdery stuff... I am betting that is just rust from water that condensed inside the cell and then charging/using it heated the water up and steamed the metal that was rusted inside bleeding outwards.

Out of about 16 AA eneloops i have only one with the rust round the positive end.

The only times I had NiMH leak (one Energizer 2500 mAh and one Eneloop) were with the Energizer 15 minutes charger. Like other people said, the stuff that leaks becomes white powdery when it dries. Btw, I don't have this charger anymore.

hmm... looks like this is quite common. :candle: next step: to research dehumidifying products...

rookiedaddy said:

hmm... looks like this is quite common. :candle: next step: to research dehumidifying products...

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dessicant packets, crackers, rice... etc

Lynx_Arc said:

crackers, rice... etc

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now... why I've never thought of using that...

rookiedaddy said:

now... why I've never thought of using that...

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You could wrap rice up in cloth and tie strings around the ends or cut open a teabag and fill it with rice and use that.

I have a few eneloops that look like this, and a couple that look a lot worse. In my case it's rust- I had a bunch get soaked by rain in a leaky bike light back in 2006. However, even for the two cells where the white paper ring around the button turned almost completely rust colored, I haven't noticed any performance degradation, and I've been using them for 4 years now since they rusted.

Lynx_Arc said:

You could wrap rice up in cloth and tie strings around the ends or cut open a teabag and fill it with rice and use that.

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Lynx_Arc, thanks for the tips. Gonna steal some tea-bag from wifey's kitchen. Does brown rice works the same?

Byydo said:

However, even for the two cells where the white paper ring around the button turned almost completely rust colored, I haven't noticed any performance degradation, and I've been using them for 4 years now since they rusted.

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Good to hear that. Gonna continue using it... but in my electric toothbrush.

rookiedaddy said:

Lynx_Arc, thanks for the tips. Gonna steal some tea-bag from wifey's kitchen. Does brown rice works the same?


Good to hear that. Gonna continue using it... but in my electric toothbrush.

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don't know if brown works better or not, I only know it must work because people use it in salt and sugar shakers, but my folks always put a cracker in their sugar dispenser mainly because the hole would allow rice to pour through I figure. You could google around "absorbing excess moisture" and see what comes up.

Got 12 Eneloops, used them to the point where some of the label is wearing off. I've seen nothing like this on any of them. It's probably the humidity. The fridge seems like a safe bet, I think...

If any of you care about that rust Caig D5 De-oxit should stop it from growing and/or help prevent other cells in high humidity from getting rust spots.

D5 leaves a film so no need to leave liquid on the battery, especially on the light head contact area if your head rotates to switch modes. It won't harm anything, just is less exact in switching.

I noticed this just today with my 2500 Energizers. They are crap batteries to begin with and from 2005. The only major encounter with liquids was when i recently dropped a flashlight in a sink full of water. Batteries were not wet though they did get some drops. The other end of the flashlight that houses the light was flooding with water though. Amazingly the light still functioned normally. It was quite an amusement to say the least that the light housing was flooded with water with the light still shining. Don't know if that's what caused it or it was something else. Never seen any battery do that, but after almost 10 years of the batteries taking abuse i don't think it's that surprising.

I have seen Nicads develop a crystal white substance around the positive terminal. I just threw them out.