The size 312 hearing aid battery, identified by its brown color coding, powers many common hearing devices. These small, button-shaped batteries utilize zinc-air technology, which requires oxygen from the surrounding air to generate power. They remain dormant while the protective tab is in place, only beginning to function once the seal is removed and air enters the cell. Understanding which 312 brand offers the best combination of reliability and longevity is important, as hearing aid performance is directly tied to the consistency of its power source.
Key Performance Metrics for 312 Batteries
The quality of a 312 battery is determined by several factors beyond total longevity. Performance consistency, known as output stability, is a primary metric for maintaining clear sound quality. Zinc-air batteries should maintain a stable voltage, typically around 1.4 volts, until the end of their life cycle.
Voltage stability measures how well the battery sustains power delivery before dropping off. Poor stability can cause sound distortion or unexpected shutdowns, while a quality cell provides consistent amplification until fully depleted. Overall lifespan, or capacity, is the most commonly cited metric and generally ranges between 105 and 120 hours under real-world conditions.
Shelf life is the duration a battery can be stored in its original, unopened packaging before performance degrades. High-quality 312 batteries are designed with a shelf life of three to four years, provided the factory seal remains intact. The freshness of the cell upon purchase is a direct indicator of its potential performance.
Comparative Review of Leading Battery Brands
Duracell (ProCell)
Duracell, often sold under the ProCell label, consistently demonstrates superior overall capacity in independent tests. Their 312 batteries frequently provide power close to the upper limit of the expected 105 to 120-hour range. This makes them a preference for users who prioritize maximum days of use.
Rayovac
Rayovac is known for its focus on consistency and reliability rather than maximum longevity. This brand is praised for maintaining stable voltage output and has a strong reputation in the audiology community for producing a dependable power curve. Rayovac’s 312 batteries are highly available with competitive pricing, offering a balance between performance and cost.
Power One
Power One batteries, manufactured by Varta Microbattery, are recognized for precise manufacturing and quality control. The company claims every unit is tested for reliability. This brand is popular among audiologists and often performs well in tests of voltage stability, making them a strong option for advanced hearing aids sensitive to minor voltage fluctuations.
Energizer (Eveready)
Energizer, along with its professional-grade Eveready line, offers a reliable battery that competes directly with the other major brands. Energizer is known for its consistent power supply and long life, offering a dependable choice for general daily use. The choice between these leading brands often comes down to individual device compatibility and the user’s preference for longevity versus voltage consistency.
Maximizing Performance and Shelf Life
The user’s handling and storage habits significantly impact the actual life of a 312 battery, regardless of the brand selected. Proper activation begins the moment the protective tab is removed, allowing oxygen to enter the cell. After removing the tab, wait one to five minutes before inserting the battery into the hearing aid. This waiting period allows the zinc-air chemical reaction to fully initiate, bringing the battery to its optimal voltage of approximately 1.4 volts.
Unused batteries should be stored in their original packaging at room temperature in a cool, dry place. Storing batteries in high-humidity areas, like a bathroom, or in extreme temperatures can reduce shelf life and operational capacity. The original packaging protects the air holes from accidental oxygen exposure and prevents premature discharge if the cell contacts metal objects.
Consumers should always check the expiration date printed on the packaging, as zinc-air batteries lose a small percentage of charge annually, even with the tab intact. It is better to purchase smaller quantities more frequently than to stockpile large amounts. Environmental conditions also play a part, as both excessively dry air and high humidity may reduce the battery’s operating life.