AA Batteries are corroding!

[GoingFastTurningLeft]

Well, my girlfriend bought me an electronic soft-tip dart board a few months ago. We put 4 new AA batteries in it, used it once and didn't come back to it. Last week I finally hang the thing up, and it doesn't work. Open the battery hatch and there's corrosion everywhere!

I put in some AA batteries I had laying around, 2 duracells and 2 rayovacs, and it worked fine 1-2 weeks ago. I try it today, doesn't turn on, and it looks like these batteries are starting to corrode!

What the heck is going on? What would cause this at such an accelerated rate? I've never seen batteries do this, except in things I haven't used for a few years!

[GoingFastTurningLeft]

I'm wondering if its because there isn't a 'hard' on/off switch - i think all the buttons, including the power, is a momentary switch. If so, then it's got to constantly be 'on' and always draining power. Maybe its completely draining the batteries, then the batteries are falling apart.

Either way.... this is a pretty bad circuit design if you leave batteries in it for a few months and your batteries have fallen apart!

[Robert Reed]

My digital camera which I purchased two years ago would kill even the best double A s in two months of just sitting on the shelf. I took it apart and did some measurments and found that it stills draws almost 1 ma in the off position. Must be something to do with internal memmory. Did some quick math and yes two months at 1 miiliamp is the life of the battery. No corrsion though - that sounds serious.

[Janitor Tzap]

Hmm......

Well, that is strange.

The old batteries that were in the game, were they standard Carbon batteries?
Or were they Alkaline?

Standard Carbon Batteries will leak acid when they die.
Thus, corroding the battery contacts inside battery holder or compartment.
Alkaline Batteries don't leak as easily. But I have seen some of the cheaper brands that do.

Use water and Baking Soda on the contacts to stop them from continuing to corrode.
Also use the water & Baking Soda to clean the acid out of the inside of battery holder or compartment.
Dry it off and check the contacts.
They may still have some corrosion.
Take some 200 Grit Sand paper and sand the contacts with it.
Or get a Rubber Eraser and use it on the contacts.
It doesn't have to be perfect, just good enough to make connections with the batteries.

I agree with Robert, that the game is probably drawing some power.
Even when it is suppose to be off.
This is why some of the manufacturers of battery operated games
state that if your not going to use the game for long periods or store it.
To remove the batteries.
Thou.....
They also recommend using only Alkaline Batteries, because they last longer.

One thing I have done on some games is install a Slide ON/OFF Switch
in between the Positive lead(+) going to the main board and the Positive Out(+) on the battery holder or compartment.

You will loose scores that were stored in the memory.
But you will lessen the chance of killing the batteries.


Signed: Janitor Tzap

[MrAl]

Hi there,

I see alkaline batteries leak all the time. The ones that leak the worst
are the Rayovacs. Long time back, i always used Rayovacs because
they were the cheapest when there was a sale. What i found out
was that in the pack of 8 or 12 or whatever, ALWAYS at least one
cell would leak which would get white stuff all over the other cells too.
This meant the pack had to be inspected to find out which cell(s) leaked
and throw that one out and maybe keep the rest.
Now since then Rayovac came out with a new design, in the 'silver'
color package. I had hoped they improved the leak problem, so
i bought a couple packs. To my surprise, after only a short time
(less than 6 months) one of the cells leaked! As far as i can tell,
they havent improved anything.
A friend of mine had the same thing happen. One cell leaked in a
20 dollar flashlight and it rotted one of the rivits that holds one of
the battery springs in place, spring fell out, flashlight not useable
anymore. They might have a guarentee, but you have to send it
to them first.
What we have learned from years of using different alkaline cells is
that any brand 'can' leak, even if not used, but the Rayovacs seem to
be the worst of all of them so you have to be careful and check your
device every month if you leave Rayovacs in them.
What else we have learned is that most digital cameras drain the cells
even when the camera is off (as someone else pointed out too).
This means we always take our cells out regardless of brand when
we are not using the cameras. I measured my camera too, and it
read 300ua or something like that when it is turned off. I figured it
could drain the cells significantly within 3 months if the cells were
left in the camera, so out they come after each use.

BTW, i have nothing against Rayovac, and in fact they 'were' my
favorite battery company some years ago because they had the
only cell that would work in my graphing hand calculator (TI-85)
besides alkalines which would run down too fast and make it
rather expensive to run the thing for long.
The type of cell was called "Renewal" and it was rechargable, with their
special charger. The NiCd AAA cells were not worth anything at the time
so i couldnt use them or i would have to recharge them every hour haha.
There were no NiMH cells either at the time.
One thing that bugged me though, is that Rayovac at the time claimed
50 recharge cycles, but you were lucky to get 10. Still, they were cheaper
than alkalines in the long run.
They stopped making them however, but they are made under a new
name by another company i think in Canada, but i dont recommend
wasting money on them now that Eneloop NiMH cells are available.
The Eneloops act like NiMH, but have less self discharge, meaning they
hold their charge much longer when they are not being used. Typical
standard NiMH can loose a lot of their charge in only one month. In
two months hardly usable for long.

Ok back to the subject...
It's always best to take the cells out of a camera when not in use, but
it's also wise to check your device every so often no matter what kind
of device it is or what brand of cells are in it, unless they are Rayovacs,
in which case you should check it VERY often.

I still buy Rayovacs on sale but i dont use them in anything too expensive,
and i keep an eye on them when i do use them in something.

[dacflyer]

did you clean up and get rid of all the corrosion before installing the new batterys?

if not i am guessing the corrosion is contaminating the new batterys..

also i think i read you right you said you was using mixed brands of batterys? i do not know if thats a concern or not. i always see notes saying not to mix batterys in products..

but as a rule of thumb,, if i am not going to use something battery powered for a while, i just remove the cells..

[jollyrgr]

I've had good luck with the Rayovacs and buy them because the are cheap. But enough about that.

I'm guessing the first set leaked as there was something wrong with one of the batteries that caused the others to fail. But the big no no is the mixing of batteries. It is especially important not to mix Carbon and Alkaline batteries as they have different life spans. This means that after the carbon zinc batteries have given their life up the alkaline are still good. This will setup a current throught the "dead" batteries; not good. I suppose the same can happen when mixing weaker and new alkaline batteries as well.

As others have stated you must clean the old corrosion out. Baking soda and warm water is excellent. I clean my car batteries with this mixture probably once a year or maybe once every other year. An old toothbrush works well for this type of job.

[GoingFastTurningLeft]

Yes, they were Alkaline. You know... in my days I don't think I've ever noticed a non rechargable AA battery that wasn't alkaline.

I agree on the Rayovacs - cheap. But I never had a problem with them until now. These are the silver and blue ones. It also seems like the leaks were all at the cathode.

I am going to install a hard on/off switch. I don't even think the thing keeps high scores, it's just a bad design! There isn't even a reason to keep a high score, I mean all I play on it is 501.

[haklesup]

I put in some AA batteries I had laying around, 2 duracells and 2 rayovacs, and it worked fine 1-2 weeks ago. I try it today, doesn't turn on, and it looks like these batteries are starting to corrode!

That's it right there. You mixed batteries from 2 brands all of unknown freshness. Just about every battery manufacturer advises against this and its not just to sell more batteries.

When you populate a battery pack with 4 batteries each having different charge, one may act as a load causing premature depletion of the other batteries and also reducing the current available to the load. This is what unfresh or partially used batteries can do. Not only that but mixing brands sets up the situation where the batteries may have different capacities and discharge curves making the problem above occur when it runs down. There's more subtleties to it and you could learn more from app notes on a battery website.

Not that we all don't do it, I sure do, but I try to limit it to devices I use frequently like a remote control or camera so I know pretty soon when the batteries are dead. Most only leak after dead but I suppose its possible to leak while charged. I've even had batteries leak on the shelf.

Its also possible that incomplete cleaning of the first leak left acid in place that accelerated the corrosion on the newer batteries. Obviously better cleaning is the fix for that.

[GoingFastTurningLeft]

Once when I was a kid, I had a light that went on the front of my original game boy (You know, the big, 4 shades of green lcd, non-backlit one!).

I remember playing it once and the light got dim and I heard a "PANG!" then it didn't work.

When I got home I noticed there was all this black crap on the inside. At least, I remember it being black-ish. This was probably around 1990.

That's probably the last time I had a problem with batteries. I think my track record is pretty good!

Guess now that I can afford batteries I shouldn't be a cheap-skate!

[jollyrgr]

Exploding and/or leaking batteries:

My brother and I were checking out portable CD players (in the old days when they cost $100 or more). The player would not play so the clerk was changing the batteries. She/he put the batteries on the glass counter (mind you the battery was not slammed down or anything) and it started to roll off the counter. My brother grabbed it before it could roll off the counter and picked it up. The end blew out of it spraying my jacket with internal gunk from the battery and getting the same on my brother's face. We filled out an incident report about this. The battery manufacturer sent us free flashlights for our trouble. This was the copper top battery.

I carry a 3 D Cell MAG light flashlight in my car. Of course the batteries get bounced around even though the flashlight is wedged in between the center console and the passenger seat. Twice I've had the "pink bunny" type batteries rub through the outer jacket and touch the metal of the flashlight barrel. This results in a shorted battery and a mess.

There is a real interesting battery I have had for many years now. It is an AA battery and only a carbon zinc if I recall correctly. It is in an LCD digital desk clock. The battery is likely over 25 years old and is still working. I got the clock well before I had my driver's license as I rode my bike to the garage sale from where I got it. The battery in it at the time was one of those "no name" freebie batteries you get with those "office gift" type things.

[ecerfoglio]

As others have stated you must clean the old corrosion out. Baking soda and warm water is excellent. I clean my car batteries with this mixture probably once a year or maybe once every other year. An old toothbrush works well for this type of job.

Baking soda is an alkali, usefull for cleaning an acid battery leakeage (like a car´s lead acid one).

For alkaline battery leakeage you must use an acid like vinegar. Of course, you must rinse away completely after cleaning.

The (discarded ) toothbruh is an excelent cleaning tool

[GoingFastTurningLeft]

There is a real interesting battery I have had for many years now. It is an AA battery and only a carbon zinc if I recall correctly. It is in an LCD digital desk clock. The battery is likely over 25 years old and is still working. I got the clock well before I had my driver's license as I rode my bike to the garage sale from where I got it. The battery in it at the time was one of those "no name" freebie batteries you get with those "office gift" type things.

That's interesting. I found an old casio digital waterproof watch in my basement. Thing is still going. Has to be at least 15 years old. I found it cause apparently there is an alarm set on it, not sure if it's just at an odd time or once a week or whatever, but it went off. I should see how far it's drifted.

Anyway, this is getting off topic and I think we've discussed this problem and its remedies completely. Thanks for all the useful info everyone!

[Chris Smith]

Large currents even for short periods of time will heat up a battery and change its chemistry.

If enough damage is done it can create a hot and or expanding gas and explode.