Hearing aids rely on a consistent power source to process sound and deliver amplification throughout the day. Two primary categories currently dominate the market: disposable zinc-air batteries and integrated rechargeable systems. Each option presents a distinct user experience, differing in daily maintenance, longevity, and overall convenience. Understanding the specific power source is important for ensuring continuous, high-quality hearing performance.
The Standardized System of Disposable Batteries
Disposable hearing aids primarily utilize zinc-air batteries, a chemistry that draws oxygen from the surrounding air to generate power. This process provides the steady, constant voltage required for digital hearing aid processors. To prevent activation before use, these batteries are sealed with a protective adhesive tab that covers the air holes on the casing.
A universal color-coding system helps users quickly identify the correct size, as the physical dimensions are small and often difficult to distinguish. The four standardized sizes are recognized globally, each corresponding to a specific color and number.
The four standardized sizes are:
- Size 10 (Yellow): Used in the most discreet completely-in-canal (CIC) hearing aids.
- Size 312 (Brown): Powers many receiver-in-canal (RIC) and mini behind-the-ear (BTE) models.
- Size 13 (Orange): Required for larger devices, such as standard BTE and in-the-ear (ITE) hearing aids.
- Size 675 (Blue): The largest option, reserved for high-power BTE instruments designed for severe to profound hearing loss.
Maximizing the Life of Zinc-Air Batteries
Getting maximum performance from a zinc-air battery depends heavily on proper activation and handling. Before inserting a new battery, the protective tab must be completely removed to expose the air holes, which initiates the chemical reaction. It is beneficial to allow the battery to “breathe” for one to five minutes after the tab is removed. This brief waiting period allows oxygen to fully saturate the zinc material and helps the battery reach its optimal voltage, ensuring a consistent power output.
Proper storage of unused batteries is important to maintain their shelf life, which can be up to three years with the tab intact. They should be kept at room temperature in a cool, dry place, and should never be stored in a refrigerator, as the cold and humidity can damage the seal or internal components. When the hearing aid is not in use, opening the battery door breaks the electrical circuit and conserves power, while also allowing any accumulated moisture to evaporate.
Factors Affecting Battery Drain
Certain factors inherent to hearing aid use can accelerate battery drain. Features like wireless audio streaming, high-volume settings, and constant use of advanced processing algorithms all increase the current draw on the small power cell. Additionally, environmental factors like high humidity and extreme temperatures can negatively impact the battery’s performance and longevity.
The Alternative: Rechargeable Hearing Aid Systems
Rechargeable hearing aids offer a modern alternative to the continuous need for disposable batteries, relying on integrated power cells that are not meant to be removed by the user. The dominant chemistry is Lithium-ion, which provides a high energy density in a small package, similar to the batteries found in smartphones. This technology allows the device to be placed in a dedicated charging cradle overnight, providing a full day’s worth of power after only a few hours of charging.
The convenience of a rechargeable system eliminates the manual task of frequently changing small disposable batteries, which is a benefit for users with limited dexterity. A single full charge typically provides up to 24 hours of use. However, these systems require a consistent nightly routine, and forgetting to charge them leaves the user with limited or no hearing function until they can be docked again.
Unlike disposable batteries, the Lithium-ion cells are sealed within the casing and are designed to last for the lifespan of the device, often maintaining their capacity for four to five years. This approach reduces the ongoing cost and environmental waste associated with discarding zinc-air batteries. While Lithium-ion is the standard, some models use silver-zinc rechargeable batteries.