Gallery, Projects and General => Oooops! => Topic started by: Pete W. on October 19, 2014, 09:19:05 AM

Title: Leaking Dry Batteries!!
Post by: Pete W. on October 19, 2014, 09:19:05 AM
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? 
Title: Re: Leaking Dry Batteries!!
Post by: lordedmond on October 19, 2014, 09:54:20 AM
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

Title: Re: Leaking Dry Batteries!!
Post by: Pete W. on October 21, 2014, 03:45:56 AM
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.     
Title: Re: Leaking Dry Batteries!!
Post by: awemawson on October 21, 2014, 04:23:47 AM
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.
Title: Re: Leaking Dry Batteries!!
Post by: Frank88 on January 23, 2016, 06:38:48 PM
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 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.
Title: Re: Leaking Dry Batteries!!
Post by: John Swift on January 24, 2016, 06:00:11 AM
Hi Frank

welcome to Mad Modders

I don't know if you have read this -,2583.msg45845.html#msg45845

an old post about recharging batteries

Title: Re: Leaking Dry Batteries!!
Post by: Pete W. on January 24, 2016, 09:30:52 AM
Hi there, Andrew and Frank,

Thank you both for your posts.

Andrew, Servisol contact cleaner is a stock item in my 'alchemy' cupboard.

Frank, it's OK to have 'bumped' this thread as it reminds me that this keyboard job is still outstanding.  It got displaced to the back burner by our annual 'tidy the living-room ready for Christmas' ritual!!!  I never use WD40 on electrical contacts since a fellow member of Hornchurch Amateur Radio Club sprayed WD40 on the multi-wafer wave-change switch in her communications receiver - it NEVER worked again!!  I might use WD40 as a water dispersant but only where there is no question of it getting on sliding or make-&-break electical contacts.  (I know I'm the only one in-step but I don't use it as a cutting lubricant for aluminium either!  What's wrong with the smell of white spirit for goodness sake?!?!) 
Title: Re: Leaking Dry Batteries!!
Post by: awemawson on January 24, 2016, 10:14:28 AM
I'm sure decades ago I used to go to 'radio rallies' at Hornchurch ARC  :bugeye:
Title: Re: Leaking Dry Batteries!!
Post by: Frank88 on January 24, 2016, 10:30:59 AM
Thanks for the welcome. I only use the WD 40 on simple AC or DC circuits, mostly solar yard lights, flashlights and the like. Thanks for the heads up as caution indicated. Wonder if the phenolic in the wafers became impregnated?. Found this after reading your most welcome comments -
Title: Re: Leaking Dry Batteries!!
Post by: Bluechip on January 24, 2016, 10:37:01 AM
I wouldn't use WD40 for electrical parts either. Been caught in the past.  :zap:

Although I do use it for machining aluminium and it is quite effective for downing wasps prior to the application of the 'compression test' boot.

Title: Re: Leaking Dry Batteries!!
Post by: Pete W. on January 24, 2016, 12:58:10 PM
Hi there, Andrew,

This post is going to be  :offtopic: but it is my thread, after all!!   :ddb:   :ddb:   :ddb: 

I'm sure decades ago I used to go to 'radio rallies' at Hornchurch ARC  :bugeye:

I got the name of the club wrong - ancient grey cells!!!  It was/is actually Havering & District Amateur Radio Club.  I joined in 1980 and left in about 1995, shortly before I moved out of the district.  The 'London Borough of Havering' comprises Romford, Hornchurch, Upminster and Rainham.  After the borough was formed it was named after the tiny village of Havering, presumably to avoid bickering between the merged councils.  Henry VIII had a hunting lodge at Havering, some refer to it as a palace, and Queen Elizabeth the First is supposed to have spent some of her childhood years there.  Havering is at the top of a hill (yes, there ARE hills in Essex) and it was apparently possible to see the sails of ships on the River Thames from the brink of the hill.

In my time, H&DARC didn't actually hold rallies but we regularly used to visit rallies at Chelmsford, Canvey Island and Colchester.  Some of us were regular visitors to the VHF Convention that used to be held at Sandown Race Course.  One of the club members was a bus driver and could hire a bus for a very friendly price.  This facility often helped club members to attend other rallies at more distant venues such as Longleat.  I am now faced with the downside of attending all those rallies (with their flea markets) i.e. the burden of trying to constructively dispose of all the techno-jumble that I bought but never used.

If anyone disputes my claim that there are hills in Essex, they should visit the site of the one time GPO Radio Station on the Epping Upland, overlooking North Weald.  I understand that the antennas have now gone but there is also a Palmerston Fort on the same site.  A few miles further to the East is 'Toot Hill' - the word 'toot' is Old English for 'look out' or 'lookout'.  Hence its use by Mr. Toad of Toad Hall while careering about in his motor car!