Gallery, Projects and General > Oooops!

Leaking Dry Batteries!!

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Pete W.:
Hi there, all,

This isn't my 'Oops!', I'm trying to help a friend.

They left the batteries in the wireless keyboard of their Mac computer and the batteries have leaked.  I think they're the 'long-life' alkaline type rather than simple zinc/carbon but they're not Duracell, I can see a yellow plastic outer sleeve.  For those who don't know the Apple Mac wireless keyboard, the housing is aluminium alloy, looks as though it's natural anodised finish.

So far I've managed to remove one cell and the base of the second one but most of the second one is still stuck in there.  The battery compartment is a tubular space, only 13 mm in diameter and the visibility gets more difficult the further I penetrate!!

My question is this:  how does the chemistry of the 'long-life' cells differ from the simple zinc/carbon cells?  I know the latter use sal-ammoniac with a manganese dioxide depolariser.  What might I be able to use to carefully irrigate the back of the cell to loosen the grip of the white deposit? 

lordedmond:
Cannot help with the chemistry bit
But if it a older KB. There are three cells in there

To find out look under ther is is a small logo that shows the battery directions newer one have two


Stuart

Pete W.:
Hi there, Stuart,

Thank you for your reply.

I've been researching this situation elsewhere on the Internet.  I gather that the corrosion products from long-life battery leakage are alkaline, so the way to go is to use a mild acid to dissolve them (followed by thorough rinsing, of course).  White cider vinegar has been mentioned but I'm thinking I shall initially try citric acid.  I do still have some from our experiements with rust removal reported in another thread.

I also found recommendations to use WD40 but that doesn't chime with me for this application.

The corrosion in this case has largely run it's course so there's no rush.  So I plan to scrape some of the corrosion products into a Petri dish, add some citric acid and see if the one dissolves the other.  If that works then I'll try some citric acid in the battery compartment.     

awemawson:
Pete, my first thought was citric acid, but as you know I do have a tendency to use it all over the place.

When the battery is eventually out and the corrosion products removed get it thoroughly dry then spray it with 'switch lubricant' which is also a corrosion inhibitor.

http://www.ebay.co.uk/itm/Servisol-Super-10-Switch-Contact-Cleaner-/281455629291?pt=UK_Sound_Vision_Other&hash=item41881013eb

Frank88:
I know this is a new thread to an old post. I have been experimenting with DC recharging of alkaline cells for a couple of years with mostly good results. With prices in my area reaching $ .75 cents per cell we may see a renewed effort at cell recharging. The leakage problem created by the generation of hydrogen gas is never ending and tough to deal with. As stated correctly in the earlier threads the white powder is alkaline and needs to be taken back to normal Ph. I have generally used any type vinegar and at times plain water on a Q-tip to clean up and neutralizing the white powder (potassium hydroxide exposed to carbon dioxide in the air forming an ever growing layer of potassium carbonate) see https://en.wikipedia.org/wiki/Alkaline_battery. The biggest problem is the destruction of the metal contact surfaces and circuit traces. After oxidation has been removed I lightly sand the surfaces and apply a light coating of petroleum jelly to the surfaces and the ends of the new battery to control new corrosion from air contact with the surfaces that had been etched by the electrolyte. If for some reason water had entered the circuit area I spray it with WD 40. It is not a lubricant but was developed for the military to remove water from electronics, and is flammable. Seems like a lot of trouble when the simple answer to the problem is making the devise with enough cell holders to make up for the .3 volts per cell deficit in voltage.
I would like to thank the moderator and very clever member participants for making it possible to contribute to and help solve problems. Here is the first place I learned of using modified AC as a recharge method.

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