Hearing aid batteries are not all the same. While they may appear similar in their small, button-cell design, these power sources vary significantly across several factors, including physical size, chemical composition, and the type of power system they support (disposable or rechargeable). Understanding these distinctions is necessary for ensuring your hearing aids function consistently and reliably.
The Universal Color Coding for Battery Sizes
Hearing aid batteries use a globally standardized color-coding system to help users identify the required size for their specific device. There are four main sizes, each corresponding to a unique color printed on the packaging. The hearing aid model itself dictates the specific battery size required.
- Size 10 (Yellow): Used in nearly invisible Completely-in-Canal (CIC) and smaller Receiver-in-the-Ear (RITE) models.
- Size 312 (Brown): Found frequently in mini Behind-the-Ear (BTE) and In-the-Ear (ITE) hearing aids, offering a moderate lifespan.
- Size 13 (Orange): Provides a longer run-time and is typically used in larger BTE and ITE devices.
- Size 675 (Blue): The largest standard size, reserved for high-power BTE hearing aids or cochlear implants, offering the longest battery life.
How Zinc-Air Technology Powers Hearing Aids
The most common disposable hearing aid batteries rely on zinc-air technology. This chemistry is effective because it uses oxygen from the surrounding air as one of the reactants to generate power. The battery itself contains zinc powder mixed with an electrolyte.
For the battery to remain inert until use, a protective sticker tab seals the air holes on the casing. Once this tab is removed, oxygen enters the battery and reacts with the zinc, which generates an electrical current. It is recommended to let the battery “breathe” for around 60 seconds after removing the tab, allowing the reaction to fully activate before insertion.
Disposable Versus Rechargeable Power Systems
Consumers today face a choice between disposable zinc-air batteries and modern rechargeable systems. Disposable batteries are inexpensive and offer a quick fix when power runs out, typically lasting between three and fourteen days. However, the need for frequent replacement can be cumbersome for some users and contributes to electronic waste over time.
Rechargeable hearing aids typically utilize built-in lithium-ion or silver-zinc cells that eliminate the need for regular battery changes. These systems offer all-day power on a single overnight charge and reduce the hassle of handling tiny batteries. While the initial cost of rechargeable hearing aids is higher, the cells can last one to five years before needing replacement.
Maximizing Battery Life and Performance
Proper handling and storage maximize the performance of both disposable and rechargeable hearing aid batteries. Disposable zinc-air batteries should be stored in a cool, dry place until they are needed, as extreme heat or cold can shorten their lifespan. Avoid carrying loose batteries where they might contact metal objects, which can cause a short circuit and drain the power prematurely.
To conserve power in a disposable system, turn off the hearing aid or open the battery door overnight when not in use. For rechargeable models, maintaining consistent charging habits is helpful, as they are designed to be placed in the charging dock every night. Avoiding complete deep discharges helps maintain the cell’s capacity over its multi-year lifespan.