Hearing aids like any other electronic device need power for operation. Traditionally, hearing aids used non-rechargeable one-time-use button cells that were replaced after every few days. However, new hearing aids use rechargeable batteries that last a big part of the day before running out of juice. Both button and rechargeable batteries have their own pros and cons, and it is important for you to do proper research on your hearing aid batteries and the charging options.

Why do batteries in hearing aids matter so much?

It’s like comparing a gasoline-powered car with an electric car. A gasoline car provides more range and freedom and gas stations are literally everywhere you go, so there’s no need to worry about refueling, but they lack smart features and have a terrible amount of moving parts requiring maintenance. 

When it comes to electric cars, the features are impressive and you get more automation, but you lose points at range and charging points limitations. The difference in the lifestyle between a gasoline car owner and an electric car owner is drastic, as they plan their days according to the limitations they can face.

Similarly, the choice you make for your hearing aid’s battery can be a huge decisive factor behind your user experience with the device. Understanding your hearing aid batteries’ limitations and charging options will help you use your hearing aids seamlessly.

Rechargeable Batteries in Hearing Aids

High-end digital hearing aids come with lithium-ion rechargeable batteries that are exactly the same as the ones in your smartphones. You need to charge them after a good amount of use. Typically, good batteries in hearing aids last about 16 hours of use time.

Lithium-ion rechargeable batteries have become pretty commonplace in electronics nowadays thanks to their long shelf life and environment-friendly carbon and elemental footprint
Rechargeable batteries in hearing aids

Benefits

Long Shelf Life

One of the greatest benefits of having a rechargeable battery in your hearing aids is the excellent shelf life. Thanks to advanced battery technology, rechargeable batteries can now hold a charge for several days when on standby mode. The battery health starts to deteriorate at least after a couple of years and with good care, you can make your battery health last as long as 5 years.

Environment Friendliness

Another advantage of using rechargeable batteries is environmental friendliness. You don’t throw out batteries in your rubbish bin after every 14 days because they can be recharged and be good as new.

Ease of use

If you are the type of person who has dexterity problems or finds buying and replacing batteries every few days a hassle, rechargeable batteries are the best option for you. You can forget about getting new power packs in order to listen better as you can simply put your hearing aids on charging before going to bed and wake up with an entire workday's worth of battery juice.

Drawbacks

Lack of right to self-repair/user control

Many companies that offer rechargeable batteries design their hearing aids in a way where the batteries cannot be replaced in case of failure. In case a customer tries to open the casing or charging unit, the warranty is voided. This is normally done so that companies can leach out more money from the customer through repair costs - just another example of companies not following the right-to-repair law.

Dependence on a charging brick/casing/unit

Most rechargeable hearing aids require a separate charging system. This means that you have one more thing to carry with you at all times if you want to get complete day coverage. Even though these casings are small and portable, they can easily be lost and left behind, which means you will have to buy a new charging casing/holder from your hearing aid company.

Zinc-Air (Disposable) Batteries in Hearing Aids

Before rechargeable batteries, hearing aids used to have standard disposable batteries that are often referred to as ‘button cells’. Zinc-Air batteries have been there for quite some time now. They feature a special protective seal made up of plastic that protects the Zinc surface of the battery from coming in contact with the air. Once removed, the Zinc and air come in contact, and the battery is activated. From that point on, the battery cannot be deactivated. 

Even today, some hearing aids feature these button cells instead of rechargeable batteries. These disposable batteries in many shapes and variants, as per the product specification.

Benefits

Quick fix

One of the best advantages of sticking with disposable batteries is the convenience of being able to pop in a fresh battery whenever a cell runs out. Worry not if your hearing aid dies right in the middle of Beethoven’s 5th Symphony in C minor because you can quickly and easily switch it out for a fresh battery in time to catch the drop to A-flat major.

An advantage disposable batteries have over rechargeable batteries when it comes to hearing aids is the ability to quickly swap for a fresh battery and get the hearing aid to work again unlike rechargeable batteries which need to be charged for a few hours.
Disposable Zinc-air batteries in hearing aids are easily swappable

Light, easy and portable

You do not need to keep anything extra with you to support your hearing aids through a journey. These cells are affordable and can be bought in bulk at a great value, which means the only things you need to listen better are your hearing aids and some leaflets full of button cells in your wallet.

Drawbacks

More expensive in the long term

On average, a hearing aid user would go through about 100 disposable cells each year. That is a huge amount of battery cells that you will need to buy and this cost can stack up in the long term compared to rechargeable hearing aids that you have to pay for only once.

Hazardous for the environment

Ideally, the exhausted batteries are taken to recycling centers but for those that find their way into the regular trash and eventually landfills, they have serious implications for our environment as highly toxic metal waste can leak into the soil and make its way into the water bodies, destroying aquatic ecosystems.

Different sizes and color coding

The four most common disposable battery sizes used in hearing aids are all smaller than the diameter of a dime. All these batteries have been color-coded by the industry to avoid any confusion for the consumer, as all of them are extremely small in size and have a similar physical footprint.

  • Size 10: 5.8 mm wide by 3.6 mm high - yellow
  • Size 312: 7.9 mm wide by 3.6 mm high - brown
  • Size 13: 7.9 mm wide by 5.4 mm high - orange
  • Size 675: 11.6 mm wide by 5.4 mm high - blue

Disposable zinc-air batteries in hearing aids have been color-coded according to their sizes so that customers can easily identify the batteries of their requirement

Color-coded Zinc-air batteries in hearing aids

Wired Vs. Wireless Charging - Which one is better for your hearing aids?

Corded chargers objectively offer better efficiency and reliability than inductive or wireless chargers. For the most part, wired chargers deliver sustained levels of current and no unnecessary heat is produced except for the battery reverse cycling process.

In inductive chargers, air gaps are involved and electromagnetic fields are used to produce a voltage in the coils of the device, this produces unwanted heat that can damage the lifespan of your device’s battery. 

It is better to charge your hearing aid case or battery packs through a wired solution instead of an inductive one. As aesthetically pleasing induction charging looks, it is not good for electronics in the long run.

Frequently Asked Questions (FAQs)

What do the numbers on hearing aid batteries mean?

Many hearing aids still use disposable zinc-air batteries that are classified on the basis of their size through numbers and color coding to avoid confusion and enable easy replacement. The type and size of battery needed depends on the power specifications of your hearing aids and includes 10 (yellow), 13 (orange), 312 (brown), and 675 (blue).

Should rechargeable hearing aids be charged every night?

When it comes to hearing aids, the batteries must be charged every night. A full charge may take up to 7 hours—the charge time varies based on how much the battery was depleted during the day. In case you assume that there’s enough battery in your hearing aids to last you another day, an instrument might stop working in the middle of the day because of weak voltage.

Can rechargeable hearing aid batteries be replaced?

Over time your battery performance will reduce (usually after about an year). When this happens, rechargeable batteries might need to be replaced. Thanks to the nature of digital hearing aids, get your batteries replaced only through a registered franchise or the actual manufacturer.