When Alkaline Batteries “Spill Their Guts”: What Actually Happens?

Most of us have experienced it: You open an old flashlight, remote control, toy—or flow meter—and discover a crusty white mess surrounding the batteries. Sometimes the batteries are swollen, split open, or firmly corroded into the battery compartment.

So, what happened?

A Little Battery Chemistry

An alkaline battery produces electricity through a chemical reaction between zinc and manganese dioxide. Potassium hydroxide serves as the electrolyte that allows this reaction to occur. As the battery discharges, the zinc inside is gradually consumed through a chemical reaction. Corrosion can continue after the battery is depleted, sometimes producing gas and increasing pressure inside the battery.

Alkaline batteries are designed with seals that contain their internal chemicals during normal use. However, age, corrosion, temperature changes, and internal pressure can eventually cause those seals to fail. The battery may then swell, rupture, or leak its electrolyte into the surrounding equipment. In other words, the battery “spills its guts.”

What Is That White Crusty Material?

The familiar white, powdery buildup around a leaking alkaline battery is largely the result of potassium hydroxide reacting with carbon dioxide in the air and forming potassium carbonate.

Although the residue may look harmless, leaking battery chemicals are caustic. They can irritate skin and eyes and damage electrical contacts, circuit boards, wiring, and plastic components.

The longer a leaking battery remains inside a device, the greater the chance of permanent damage.

Why Do Batteries Leak While Sitting on a Shelf?

A battery does not need to be actively powering a device to deteriorate. Batteries slowly self-discharge over time, even when the equipment is not being used. This is why devices placed into long-term storage can be particularly vulnerable. The batteries may become depleted and remain unnoticed for months or years. By the time the device is needed again, leakage and corrosion may already have caused substantial damage.

How Can You Help Prevent Battery Damage?

A few simple habits can protect your equipment:

• Remove alkaline batteries from devices that will not be used for several months.

• Replace depleted batteries promptly.

• Periodically inspect equipment that is used infrequently.

• Check the expiration dates on batteries held in inventory.

• Do not mix old and new batteries.

• Do not mix different battery brands or types in the same device.

• Store batteries and battery-powered equipment in a cool, dry environment.

What Should You Do If a Battery Has Already Leaked?

If an alkaline battery has leaked, avoid touching the residue with bare skin and wash your hands after handling the device. Carefully remove and properly dispose of the damaged batteries.

To clean the battery compartment, lightly dampen a cotton swab with white vinegar and gently dab the affected areas. Do not pour vinegar into the device or saturate its electronic components. Wipe away the loosened residue and allow the compartment to dry completely before installing new batteries. If the contacts are badly corroded or damaged, check with the device manufacturer before putting it back into service.

A Note for MIC Meter Owners and Distributors

MIC Detached Display meters use customer-replaceable AA batteries. If a meter will be stored or held in inventory for several months, remove the batteries until the meter is placed into service. Once the meter is in use, replace the batteries promptly when the display begins to fade.

The batteries inside Pipe Mounted Display meters are not customer-replaceable. Please contact Midwest Instruments & Controls for battery service or questions about your meter:

Info@micmeter.com , 715-456-3977

A few minutes of preventive care can protect a valuable piece of equipment—and help ensure it is ready when you need it.