Alkaline battery vented in MDC-AA

etc

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I got my Malkoff MDC-AA and I am pretty sure it's the alkalines that did this, apparently they vented. I don't see any signs of leakage. It didn't leak, it specifically vented. I also briefly ran Energizer Lithiums in it and they could have also done it, I suppose. But I left the alkalines (Duracell) for a lot longer - overnight. I didn't see this deposit when I was swapping Lithiums out and installing Duracells.

I tried cleaning it with brake cleaner, electrical contacts cleaner and one of these oversized Q-tips (3 times larger than a normal size). That did nothing.

Also the bottom part of the LED module, where the potting is and the spring got covered with this soot-like deposit. I did clean it off, apparently the module is not damaged.

The rubber switch on the end start squeaking after the chemical treatment. I did spray the insides with WD-40 to lubricate it a bit to stop the squeak, it did nothing so washed it out with electrical contacts cleaner. The light works as normal, the switch too, just squeaks a bit.
Still, this is very strange.


NTN7NCb.jpg

WNo37TU.jpg
 

bridgman

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Sorry to hear about the damage. Maybe a wire brush chucked in a drill or a Dremel ?

That's what drives me crazy about alkaline leaks... how quickly they can happen and what a mess they can make. All of the manufacturer blurb implies that it takes weeks or months after a leak to do metal damage but that has not been my experience.
 

xxo

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That sucks - duracells are the worst leakers.

You might be able to scrub it out with some 0000 steel wool wrapped around something like a gun a cleaning brush if you have one big enough.
 

etc

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Because I examined the batteries and found no sign of leakage. I've never seen a battery do this. The batteries look fine. It looks like some corrosive gas that vented. Possibly from the Energizer L91s.
 

bykfixer

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An alkaline battery vents, which is why you often end up with the leak ooze. It seems yours vented more violently.

A few years ago I grabbed two batteries tossed in a drawer and stuck them into a plastic 2aa light. While carrying it in a jacket pocket I felt my side begin to feel warm. It was the flashlight.

I pulled it out of my pocket and it was swelling. Thinking it was a hand grenade with the pin pulled I tossed it. A bit after that "fffffttt" it poofed. No ooze was on the battery casings but the batteries had vented.

Turns out when one battery has a lot more voltage than another they attempt to equalize, which caused venting. It's why the package says "never mix batteries".

Now, usually when you grab 2 new ones from a package they have pretty similar voltage remaining. But not always. Particularly if they are a couple of years old.

Ever since, when I use a 'set' of batteries I keep them together when removed from the item, be it a light, or other electronic device. I can't tell you how many times a multi-cell light has one battery quit while the other(s) still have juice. At that point the remaining battery(s) are used for one cell items.
 

pc_light

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Hi @etc, sorry that this happened, I can relate.

In your OP you mentioned D*alkalines but in your most recent post #5 you now mention the E*L91 Lithiums. Are you saying you think venting from the Lithiums was the cause?

Inquiring minds want to know because we've always viewed the primary lithiums as the safe alternative to alkaleakers.
 
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aznsx

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As a long shot post mortem thing, if you're uncertain which cell(s) are responsible, perhaps a quick no-load / open circuit voltage check might reveal an abnormality that would be an indicator. I do not know if a cell that vented would exhibit a noticeably abnormal reading afterwards, but if you have a volt meter it's worth a quick check just to see. It might reveal nothing, but could be indicative. This is a wild guess, but you never know. If it reveals nothing, not much lost in checking.

Edit: Might be too late for this, as you may have already rage-trashed those cells:)
 
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etc

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I ran both L91s and Duracells. One of them did it. Probably Duracells but neither battery exhibits anything unusual when visually examined.

It's a vent. Not a leak.
 

desert.snake

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This plaque can be removed with an acid solution, nitric or sulfuric, but I will not recommend it, it is too dangerous for the eyes and lungs.

But if remove the switch, that is, leave the bare body and pour in food vinegar and hold for a while, this can help dissolve the plaque. + steel wool, as recommended above
 

etc

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I ran some of the same old L91s I have and I think it might be these venting. they are old and I think at one time they got wet
 

Lynx_Arc

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Alkalines can leak and you not see it. I've had bad leaks and I literally had to feel the battery to see if it was wet or not
and one battery had a little wet spot on the bottom on the wrapper not on the contact. As for voltage testing alkaleaks can be full voltage and leak. I've had batteries in a pair both measuring the same voltage one leaked and the other didn't. I've cleaned up the bad leaker and used it in other devices that are already damaged by leaks. I no longer bother trying to save a few hundred or thousand milliampere hours of power now I just throw them away not worth the hassle and now that I have mostly rechargeables in stuff it costs less than a penny to refill a rechargeable battery and the effort to clean up again after another leak is not worth a penny even. I've yet to have an L91/92 leak and have them in the car and the window sill in lights and temperature sensors. I've had a set of 4 L92 type batteries that I harvested from a pair of photo batteries (6V, 2x in series) I put in a roadside LED flare that when I wanted to use it they were dead I guess over the
more than a decade the heat did them in finally.
 

Trout River

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That is exactly why when I got my AA MDC, I immediately pulled the Panasonic alkaleak and put in a L91. Today is charging day for all my lights. I also have a back up pair for each light. I also changed out all my CR123A only lights with new SF123A's. I should be done sometime tomorrow. I need a faster charger with (36) 18650 cells to charge. Anyway, stay away from the alkaleak cells I hope you get it cleaned up good.
 

ChrisGarrett

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Yours is a story of woe.

Eneloops are your answer.

For higher drains, get the Pros, despite their shorter life span.

Chris
 

fulee9999

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today I was taking my empty batteries box to the recycling place and while packing in I noticed one of the alkaleaks opened up on its own... this was a battery that came with a headlamp a few weeks ago, I'm glad I used these up and put l91s in since then

20220905_175345.jpg
 

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