Battery acid and electrolyte damage in photographic devices

[Andreas Thaler]

I have collected some photo equipment that needs repairing in order to develop/train my repair skills.

So far, most of the problems have been where leaked battery acid and leaked electrolyte from electrolytic capacitors contaminated contacts, solder joints, wires and conductor tracks on circuit boards and even literally ate them away.

These acids/electrolytes are obviously active for decades and can spread through cables, conductor tracks or through evaporation in the device.

If you don't do anything about it, the affected device could become a total loss.


How does this happen?

Batteries and rechargeable batteries inserted in unused devices can be forgotten. After a while they begin to leak. Electrolytic capacitors age and the electrolyte they contain leaks out.

Here is a compilation of corrosion damage from some of my recent projects:


Leaked battery pack MN-2 in a Nikon Motor Drive MD-4

NCd rechargeable batteries are likely to emit particularly aggressive acid.

Corrosion caused by leaked electrolyte in a Minolta XG-M

Battery acid damage in a Canon T90

The acid had spread via the black ground cable from the battery compartment to the circuit board, where it attacked the soldering point of the cable.

Leaked AA batteries in a Minolta High-matic S2

The contacts were not damaged here.

Battery acid damage in the battery compartment of a Nikon MT-1 intervalometer

Battery acid damage in a MB-21 battery grip for the Nikon F4

What should I do?

I now take traces of leaked battery acid particularly seriously.

It is less the visible acid damage on battery contacts than the area behind it, for example in a camera.

The acid can spread through solder joints, openings and cables into the interior of the camera and cause damage that can go unnoticed.

This process can take decades and the acid remains active.

This means not only removing corrosion on the surface, but also checking the area behind the battery compartment. To do this, the camera must be partially dismantled.


Electrolytic capacitors can also cause damage due to leaking electrolyte.

The camera can still work even if electrolytic capacitors have already expired, while the electrolyte is already damaging the environment on the circuit board (conductor tracks).

The Minolta XG-M circuit board shown above is an example of this.

Three of the four electrolytic capacitors had already leaked, but the camera still worked perfectly and was otherwise in mint condition.

Therefore, cameras that are known to leak electrolytic capacitors should be checked as a precaution.

This also means partial dismantling and, if necessary, repair work.


Conclusion

• Remove batteries/rechargeable batteries from the device when not in use or check them at intervals.
• Be careful with corrosion caused by battery acid and electrolyte. The resulting damage may be greater than expected or may not be recognized from the outside.
• Cleaning/repairs are generally possible, but the device must be opened and basic knowledge of electronics and soldering is required.
• Of course, not every problem with leaking battery acid/electrolyte has to go as shown. But you should be aware of the problem.

Please pay attention to

• It is expressly stated that you should only undertake the work listed if it will not harm yourself or your device.
• Dismantling a photographic device always means the risk of possibly breaking more than it already is.
• Electrolytic capacitors can contain a charge that can be high and therefore potentially dangerous in flash units or cameras with built-in flash units.
• Short circuit due to switching errors potentially means overloading of the battery, electronic components and conductors and thus a risk of fire.
• Battery acid and electrolyte are corrosive and contact with them is harmful to health.
• Soldering and solvents/cleaning agents as well as abrasion from corrosion cause fumes/fine dust that should not be inhaled. Eye and respiratory protection are required.
• It is therefore always the right decision to leave such work to a licensed specialist company.

+++

All information provided without guarantee and use at your own risk.

 

[Andreas Thaler]

In most cases I was able to repair the damage caused by acid on the devices shown:


Nikon MN-2 and MD-4

The circuit board in the MD-4 is too badly damaged on the bottom where electronics and metal switches are located so I'm installing a replacement from an abandoned MD-4.

Before I grinded, tinned and polished the contacts on the top. It was a good exercise after all

I did not equip the MN-2 battery pack with new rechargeable batteries, but rather cleaned it and use it as a study object as it is quite rare:

Minolta XG-M

The gray cable bridges a damaged spot on a conductor track.

Canon T90

I removed the corroded solder point on the board and re-soldered the ground cable. Then I bridged a damaged spot on a conductor track on the circuit board. Finally I fixed the cable harness with Loctite.


Minolta High-matic S2

Nikon MT-1 intervalometer

MB-21

To repair acid damage, I use various tools and substances, e.g. probe, scraper, files, Dremel Stylo with metal brush and hard rubber tip, Durgol descaling solution, Aqua Purificata.

The acid must be completely removed and damaged contacts must be rebuilt if necessary.

+++

All information provided without guarantee and use at your own risk.

 

[Kino]

Even older cameras with a simple battery circuit can fall prey to acid wicking-up a stranded copper wire.

I purchased a Nikon F2 as a "parts only" body that simply needed the wire from the battery compartment to the film winding lever (simple contact switch on lever to compete circuit) replaced to make the meter functional.

Acid had wicked the entire length of the wire and destroyed the integrity of the contact. It took a bit of patience, but in the end, the repair was successful.

As you state; store your cameras, flashes and light meters with batteries removed!

It will save you much grief!

 

[Chan Tran]

I found AA alkaline to be the most troublesome especially in more recent years. They are better suited for low drain/medium drain application and they are ready to use unlike NiMH which will lose their charge even unused after a while. But the tend to leak. I have used all three main brands in the USA (Duracell, Energizer and Rayovac) and all of them leaked. Unlike in the old days they leaked because the battery is drained beyond their useful life and left in the device for a long long time. Now I found them leaked even when they still have good power left. I found them leaked even in their own package unused. I wonder if there is some kind of regulations that required them to change the chemistry which makes them more prone to leaking.

 

[BrianShaw]

The leaking problem seems to be reduced quality control of the mechanical construction during the cell manufacturing. Battery cells are essentially sealed pressure vessels and some are designed/built better than others.

Why Do Batteries Leak?

If you've ever owned an electronic device, you've almost certainly learned that alkaline batteries are prone to leak when left alone for too long. Consumer Reports explains why that happens.

www.consumerreports.org

 

[Nicholas Lindan]

The leaking electrolyte from an alkaline battery is, well, alkaline. Usually Potassium Hydroxide, a cousin of Drano drain cleaner. Acid electrolyte is found in lead-acid batteries and gel-cells. 'Battery acid' is sort of a catch-all for anything leaking out of a battery, although it properly applies to Sulfuric Acid.

The distinction only matters when it is time to clean the corrosion and general crud from a leaking cell.

Probably the best cleaner is vinegar (I suppose you could use stop bath?). Vinegar evaporates so there is no residue from its use. The reaction creates Potassium Acetate, a salt, that needs to be flushed out with lots of hot water.

The electrolyte leakage from the old Carbon-Zinc batteries is acid, usually Ammonium Chloride. As with spillage from a car battery the proper cleaning/neutralizing agent here is Sodium Bicarbonate or baking soda.

 

[Sharktooth]

The leaking electrolyte from an alkaline battery is, well, alkaline. Usually Potassium Hydroxide, a cousin of Drano drain cleaner. Acid electrolyte is found in lead-acid batteries and gel-cells. 'Battery acid' is sort of a catch-all for anything leaking out of a battery, although it properly applies to Sulfuric Acid.

The distinction only matters when it is time to clean the corrosion and general crud from a leaking cell.

Probably the best cleaner is vinegar (I suppose you could use stop bath?). Vinegar evaporates so there is no residue from its use. The reaction creates Potassium Acetate, a salt, that needs to be flushed out with lots of hot water.

The electrolyte leakage from the old Carbon-Zinc batteries is acid, usually Ammonium Chloride. As with spillage from a car battery the proper cleaning/neutralizing agent here is Sodium Bicarbonate or baking soda.

That's good advice to be aware of the type of battery, and the appropriate treatment. For alkaline batteries, I use either vinegar or lemon juice, whatever is closest at hand. Lemon juice has citric acid, which neutralizes the alkali the same way as vinegar (acetic acid).

One other thing to be wary of is electrical cleaner. Some of these cleaners can damage or dissolve some plastics, particularly polystyrene plastics. Polystyrene is a strong and inexpensive material, commonly used in plastic cutlery. It's main drawback is that is dissolves in many oils and solvents. Polystyrene is often used to make those battery holders, so they will literally crack and fall apart if sprayed with any type of solvent, such as electrical cleaner/contact cleaner. It may seem the logical choice to spray some electrical cleaner on a corroded battery holder, BUT DON'T DO IT!

 

[Chan Tran]

The leaking problem seems to be reduced quality control of the mechanical construction during the cell manufacturing. Battery cells are essentially sealed pressure vessels and some are designed/built better than others.

Why Do Batteries Leak?

If you've ever owned an electronic device, you've almost certainly learned that alkaline batteries are prone to leak when left alone for too long. Consumer Reports explains why that happens.

www.consumerreports.org

I had problems of leaking from the 3 leading manufacturers of batteries in the USA. (granted Energizer owns Rayovac). Which brand can have better quality?

 

[Sharktooth]

I had problems of leaking from the 3 leading manufacturers of batteries in the USA. (granted Energizer owns Rayovac). Which brand can have better quality?

.... and the answer is: None of them

The problem with alkaline batteries is that they're considered disposable items in the marketplace, and they are built to a price point. Manufacturers "could" make alkaline batteries that won't leak, but nobody would be willing to pay the higher price in that competitive market.

The alternative is lithium batteries. These batteries need to have a leak-free casing, since there's a fire risk if these batteries leak. That's what makes them more expensive. The higher cost of lithium batteries is primarily due to the sealing, rather than the lithium, but the perceived performance difference make the higher price easier to swallow. That being said, most consumers are still going to choose the cheaper alkalines.

If manufacturers are going to make a leak-free alkaline, it would probably cost the same as a lithium. I think we can guess how many would be sold.

A second alternative is NiMH rechargeable batteries. The pre-charged versions hold their charge for years, but they sacrifice some power. The cases are also better made and far less likely to leak. The Sanyo Eneloop batteries (now Panasonic) pioneered this type, trading off some power for long storage life. The only real problem with these is the lower voltage (1.2 vs 1.5 volts). Depending on the device, this may, or may not be an issue.

 

[BrianShaw]

… none of them, including high priced high-reliability MIL-SPEC cells. In that situation it’s common for companies using them to do lot testing to verify specs and “cherry pick” good cells, as well as x-ray/CT and destructive testing studies to verify the cell construction. All of the cell manufacturers seem to have cut corners to cut costs and some outsource to companies who build to their specs. I’m not convinced that there is a lot of verification to go with that trust as the quality sometimes just isn’t consistent. And then there is the problem of counterfeit, which plagues them all. In other words, we as consumers and users can only do the best we can do without any real assurance or guarantee.

 

[Sirius Glass]

I have had no luck using contact cleaner alone. At the minimum, one needs to disassemble or partially disassemble the equipment to evaluate which further steps are needed.

 

[ic-racer]

About six years ago I converted to Eneloop batteries which don't leak. I have them in everything including remotes and flashlights.

 

[wiltw]

Conclusion

• Remove batteries/rechargeable batteries from the device when not in use or check them at intervals.

I have found that if one simply creates an Open Circuit, corrosion and leakage of the battery can be prevented for long periods. What one needs to do is simply put place some INSULATIVE bit (tape/plastic strip) at ONE end of ONE of the batteries between the cell and its device contact, so a completed circuit is not present...in effect, the condition that is present when you buy a box of batteries...there is no completed circuit!

So, for my radio remote transmitter/receivers that are used very infrequently, they sit in my camera bag with the insulator in place, and I simply 'pull the tab' when I want to use the device, and replace the tab before I set that equipment aside for indeterminant lenths of time.

And for devices that have suffered from battery leakage, I have found that the application of Barkeeper's Friend (kitchen cleanser) power in a very small of amount of water to make a 'paste', applied to the terminals with a cotton tip swab and then wiped off with a very slightly dampend second swab, cleans up even dried leakage and can restore the contact to an almost shiny state.

 

[Truzi]

Interesting idea with Barkeeper's Friend, I'll have to try that. I usually use white vinegar. I also bought some throat swabs (basically long one-ended Q-tips) for reaching in to clean difficult spots. This reduces how much I have to disassemble.
Corroded contacts (cheaper ones) have a tendency to rust after the coating was eaten away. Following up with a thin coating of dielectric grease helps.

It is frustrating how easily batteries seem to leak anymore. They were bad, improved, then regressed over the decades. One thing I've learned is to remove batteries when I am done using a device.

 

[BrianShaw]

Barkeepers Friend is a great product. Keeps my stainless steel pots and pans really clean. It’s a mix of an acid and mild abrasive. I never thought of it in this application yet it makes perfect sense for alkaline leakage.

 

[Kodachromeguy]

Don Goldberg told me that many (a majority? ) of the Leitz MR-4 light meters are damaged or ruined because of battery leakage.

Whenever I look at used cameras on the 'bay, I ask the seller to open the battery compartment. Almost no US sellers do that in their initial listing.

 

[Andreas Thaler]

I set up a reminder on my iPhone for each set of batteries in my devices when it's time to check again.