How Long Do Hearing Aid Batteries Last?
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Hearing aid batteries typically last between three and 14 days, depending on the power of the hearing aid and the type of the battery. It’s useful to know how long hearing aid batteries last for each device, as this can help seniors calculate the overall cost of running and roughly when they need to replace batteries.
Battery Sizes and Lifespan
Batteries for hearing aids come in four main sizes: 10, 13, 312 and 675. These are usually denoted by tabs that are peeled off before inserting them into the hearing aid.
- Yellow: Size 10
- Orange: Size 13
- Brown: Size 312
- Blue: Size 675
Each hearing aid only accepts one type of battery, and the type of battery it accepts mostly depends on the size of the hearing aid. The smallest hearing aids use a size 10, and these typically include the following hearing aid subcategories:
- Completely in the canal (CIC)
- In the canal (ITC)
- In the ear (ITE)
In some cases, size 13 batteries are used for in-the-ear hearing aids, especially full-shell designs, which completely cover the concha and the antihelix. These batteries are slightly larger, but they usually last longer and offer more power.
Behind-the-ear hearing aids often use size 312 batteries, which have a brown tab. These hearing aids often need more power because they usually have more features, including telecoils, more power and higher processing requirements (usually due to more channels).
The biggest hearing aids and cochlear implants use size 675, denoted by a blue tab. This size offers the most power, but the hearing aid may make use of that power, draining it faster.
Hearing Aid Complexity
The simplest hearing aids are amplifiers, and they have low processing abilities. In most cases, they offer one or two channels, and adjustment is minimal. The smaller the hearing aid, the more likely it is to only offer simple processing. On the other hand, that means that battery life is generally longer.
Midsize hearing aids run the gamut from simple amplifiers all the way to complex models with 16 channels that can be adjusted precisely. Each of these channels represents a section of the audio spectrum and can be raised or lowered to compensate for hearing loss as needed. However, hearing aids with more channels require more processing power. In addition, the more channels there are, the more likely the hearing aid is to need software — and therefore processing power — to prevent audio smearing, a disparity between when sound is perceived by each hearing aid.
All of this costs battery life, and for a smaller battery, this can reduce lifespan to a few days.
BTE hearing aids can be even more complex, incorporating things like Bluetooth and high-quality acoustics. However, one trick that hearing aid manufacturers have learned is to place the amplifier in the ear on a bud, rather than at the top of the hearing aid. This means no power is wasted in diverting audio down a tube, helping batteries last longer. These are often called receiver-in-canal (RIC) or receiver-in-the-ear (RITE) hearing aids.
In addition, BTE hearing aids can take advantage of larger battery sizes. When Bluetooth is on, however, it can cut battery life significantly, so those who intend to take advantage of that feature should factor in the extra cost.
Making Batteries Last Longer
Hearing aid batteries usually use zinc-air chemistry, rather than conventional mercury or cadmium batteries. This is because zinc-air chemistry offers a large amount of power from a very small battery. Essentially, oxygen from the air reacts with zinc to release the power stored within.
That’s why there is a tab across the back of the batteries. When this tab is pulled, oxygen starts reacting with the zinc, and it slowly discharges electricity.
It’s crucial to reduce oxygen exposure to the battery as much as possible. While the tab is generally secure, keeping batteries inside the pack as well helps to reduce the risk of oxygen exposure even further, which helps batteries last longer. These batteries also discharge more quickly in higher temperatures with low humidity, so it’s a good idea to keep them at room temperature.
It’s also important to allow the battery to rest for a minute after peeling the tab off. This is to allow the reaction to start to produce electricity and get up to full speed. While in most cases, it’s possible to run a hearing aid within a few seconds of pulling the tab, this can reduce battery life slightly, and there is a small chance of damage to the hearing aid.
Finally, a lot of people forget to turn their hearing aids off, which means the hearing aid is running throughout the night. This is particularly the case for hearing aids with no dedicated off switch. Switching off hearing aids when they are not in use helps conserve battery life.