Duracell alkalines leaking?

They can be reset. How it works with the parts dissected: "0v 18650 - How the CID works"

Not in a digital clock that receives WWVB.

First, Proctor and Gamble spends $36 million to keep Duracel going. March 29, 2012 "Procter & Gamble Duracell Puts $36 Million in TN Facilities"

Two years later, Warren Buffet (Berkshire Hathaway) buys it for $4.7 billion in stock: Nov 13, 2014 "Buffett's Berkshire Hathaway buys P&G's Duracell"

Two years later, the US plant closings begin. July 28, 2016 "Duracell Is Closing a South Carolina Plant That Employs 430 Workers"

Nov 11th, 2016 "Duracell closing Cleveland, Tenn., packing plant by 2018"

Nov 10, 2016 "Duracell Battery (packing plant) closing Cleveland plant by 2018"

If I recall correctly in the mid 2000's the greenies forced the removal of mercury from the alkalines which was in there to absorb gasses so pressure would not build.

I've had fair luck by sanding the contacts down to bare copper and slopping on some electroless silver (silver cyanide). or plating electrolytic silver with a brush:

However, if the contacts are copper plated spring steel, forget it.

A friend found some NIZN batteries that have a higher per-cell voltage than NiMH ones; so they work in his recording microphones. He likes them.

You do need to find a charger that works on each cell individually, vs 2 in series.

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But in China, you can dump the toxic wastes anywhere.

"Bare copper"??? I've never seen battery contacts that aren't spring steel and those weren't copper plated, they were a shiny silver color.

I was asked to test some of the first Duracells to be imported into the UK. Some were cycled regularly, others were charged and left standing: they all leaked badly in less than six months.

The problem with alkaline leakage is that it is so penetrating. I had leaking rechargeables in a separate battery compartment that was joined to the main equipment by 6 inches of cable. The corrosion travelled up the cable and found its way into the main switch.

If you can catch the corrosion whilst it is still on the battery contacts, you will find that It is so hard that scraping will not remove it - however, it wipes off easily with a rag dampened with tap water.

Excellent information, Adrian. Thank you.

What's wrong with copper plated spring steel?

Sure, there is! Battery holders are replacement items, the old 'contacts' go in the recycle bin.

If you can get some good bronze music wire, it's fairly easy to make new springs to replace damaged battery contacts.

The electrolyte in alkaline batteries is potassium hydroxide. This is extremely basic and will corrode pretty much anything in its path. From Wikipedia:

Chemistry

In an alkaline battery, the negative electrode is zinc and the positive electrode is manganese dioxide. The alkaline electrolyte of potassium hydroxide is not part of the reaction, only the zinc and manganese dioxide are consumed during discharge. The alkaline electrolyte of potassium hydroxide remains, as there are equal amounts of OH- consumed and produced.

Section through an alkaline battery.

The half-reactions are:

Zn(s) + 2OH-(aq) --> ZnO(s) + H2O(l) + 2e-

Overall reaction:

Zn(s) + 2MnO2(s) --> ZnO(s) + Mn2O3(s) [e = +1.43 V]

Leaks

Alkaline batteries are prone to leaking potassium hydroxide, a caustic agent that can cause respiratory, eye and skin irritation.[note 1] Risk of this can be reduced by not attempting to recharge disposable alkaline cells, not mixing different battery types in the same device, replacing all of the batteries at the same time, storing in a dry place and at room temperature, and removing batteries for storage of devices.

All batteries gradually self-discharge (whether installed in a device or not) and dead batteries will eventually leak. Extremely high temperatures can also cause batteries to rupture and leak (such as in a car during summer) as well as decrease the shelf life of the battery.

The reason for leaks is that as batteries discharge - either through usage or gradual self-discharge - the chemistry of the cells changes and some hydrogen gas is generated. This out-gassing increases pressure in the battery. Eventually, the excess pressure either ruptures the insulating seals at the end of the battery, or the outer metal canister, or both. In addition, as the battery ages, its steel outer canister may gradually corrode or rust, which can further contribute to containment failure.

Once a leak has formed due to corrosion of the outer steel shell, potassium hydroxide absorbs carbon dioxide from the air to form a feathery crystalline structure of potassium carbonate that grows and spreads out from the battery over time, following along metal electrodes to circuit boards where it commences oxidation of copper tracks and other components, leading to permanent circuitry damage.

The leaking crystalline growths can also emerge from seams around battery covers to form a furry coating outside the device, that corrodes any objects in contact with the leaking device.

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To repair the contacts, dip a small brush in ordinary vinegar and swab the damaged area. The acetic acid will neutralize the potassium compounds. You don't have to worry about any vineagar residue. Vinegar decomposes to methane as it dries. But if you wish, you can clean any other residue with ordinary water.

Once the area has dried, coat it with a liberal dab of vaseline. Vaseline is a hydrocarbon and will help clean any oxidation and dirt from the contacts and help prevent any further corrosion from attacking the metal. Add some to the battery terminals to protect them also.

When the battery is inserted, the microscopic asperites will punch through the vaseline and make a true metal-to-metal contact. This produces a very low contact resistance which is ideal for low voltage high current applications. The residual vaseline will prevent air from entering the contact area and eliminate any further corrosion.

This process should restore the contacts to better than original performance. As others have stated, remove batteries from instruments that are seldom used to prevent damage from leaking batteries.

in my limited experience yes.

Yeah IMO there is nothing to reccomend Duracell Coppertop, you pay for the brand name and don't get quality.

they could replace the battery contacts.

I can't remember the last time I saw a product that had a battery holder separate from the product case. I have a GPS (several at this point) that had contacts built into the case in a fairly fragile way. They contacted the circuit board similarly to how they contacted the battery. A little corrosion and you need a new GPS.

Yes, fairly easy to make the spring. Much harder to get back into the device.

I'd like to see them try. I think that would end up being a $200 repair for a $100 clock ($30 wholesale).

copper oxide

battery contacts often seem to be nickel plated steel or nickel plated phosphor-bronze.

I seem to recall nickel plating is good because the oxide of nickel is also conductive. In model railroads people like brass rails, but nickel plated work better and look more realistic (like real steel rails). I guess brass is just prettier.