Hearing Aid Batteries
One of the first and most important things that you need to know when you are fitted with hearing aids is battery care and maintenance.
Hearing aids have advanced a long way in the last few years; they are significantly more discreet than their bulkier counterparts, and they now house some powerful, modern technology. One thing is the same, however, and that is the fact that all this fantastic technology needs to be powered to function.
In order to run correctly, a hearing aid needs a specially designed, high-quality battery. Without this, it’s ability will be significantly lowered and the aid will not perform to its full capacity.
Hearing aids do not take your typical AA batteries; the device would simply be too cumbersome if that were the case. There are rechargeable batteries on the market, but the most common type of hearing aid battery is the zinc-air button battery.
This battery is an excellent choice of power for smaller electronics as it provides up to three times the energy of common alkaline batteries, and it fits in a much more compact package.
These batteries come in four sizes and can be purchased at a hearing healthcare facility, online, and in many pharmacies. Choosing the right type of battery depends on your specific hearing devices, but zinc-air batteries are number and colour-coded to make it easy for you to recognise the battery that you need.
How do zinc-air batteries work?
Conventional batteries generate electrical power from chemical reactions. Zinc-air batteries use the same idea, but instead of all of the necessary ingredients being packed inside the battery cell, one of the primary reactants needed is oxygen, which is absorbed from the air.
Oxygen molecules enter the battery through tiny holes in the top and come into contact with a positively charged electrode (cathode) which is made of porous carbon. A chemical reaction ensues, and this releases two electrons that travel through a circuit to power the device – usually a cell phone or hearing aid.
Without oxygen, the batteries will not work. When you are ready to use the battery, remove the sticker on the battery and let it sit out in the air for 1-3 minutes before inserting it into your device, this activates the zinc.
- Using a reactant that is so readily available and found in the air around us saves on space, which reduces the size and weight of the battery, reducing the size and weight of the hearing aid.
- No toxic compounds
- Not highly reactive
- They can be recycled, disposed of, or, in some instances, recharged with new zinc.
- Constant contact with the air can dry up the zinc gel making the battery less powerful and more likely need to be frequently changed.
- Humid conditions can flood the cell with water vapour, again making the battery less powerful.
- Hard to recharge
What do I need to know?
These batteries are air-activated, so a factory sealed sticker is always placed on the battery as soon as they are ready to be sold. This stops the battery from being activated until you want it to be.
Once this sticker is removed, oxygen reacts with the zinc in the battery which activates it. Replacing the sticker will not deactivate the battery, so remember to keep the sticker on until you are planning to use the battery. Removing the sticker sends the battery into active mode, and it will remain active until it is drained.
When stored at room temperature in a dry environment, zinc-air batteries can remain stable for up to three years before the sticker is removed. A common misconception is to store the zinc-air batteries in the refrigerator, this has no benefit and could cause water particles to form under the sticker and may activate the battery before desired use.
Hearing aid battery sizes
Different types of hearing aids need different sizes of batteries, as they all have varying power needs. Hearing aids for severe to profound hearing loss typically require more battery power and therefore larger batteries. This tends to make the device larger – in-the-ear and in-the-canal hearing aids are not usually made for more severe hearing losses, as the size of the device does not fit the more powerful technology needed.
There are four sizes of hearing aid battery available: 10, 312, 13 and 675. A useful characteristic of these batteries are the coloured protective seals. They are standardised by size and distinguished by colour; this makes it easier to remember what size is needed when purchasing new batteries. Each manufacturer is required to follow the colour-coded system, so although they may have different names, you can rely on the coloured seal.
Hearing aid batteries can last anywhere from five to fourteen days, but their lifecycle can be as short as two or as long as twenty days.
This depends on factors like:
- Duration of time the aid is worn each day
- The technology used in the device
- The type and size of the aid
- The type and size of the battery
- Whether it is a digital or analog hearing aid
- Battery maintenance
How to extend the life of a hearing aid battery
While there aren’t any perfect ways to extend battery life, these tips will ensure the battery powers your device for as long as possible.
- Do not store batteries for too long, the longer they sit unused, the shorter their life.
- Ensure hands are clean and dry before handling the battery – water and dust can shorten the lifespan of both the battery and the hearing aid.
- Store extra hearing aid batteries at room temperature and away from any moisture.
- The plastic tab on the battery keeps it fresh while it is being stored. Once the tab is removed the battery is activated, so keep it on while it is in storage.
- Remove the batteries if the device won’t be used for an extended period. This helps to avoid corrosion and damage from trapped moisture.
- Do not carry batteries loose in pockets or bags where they might come into contact with other metal objects. This can short-circuit them.
- Open the battery door when aids are not in use so battery life is preserved and feedback cannot be picked up. This will also help to ventilate the aid and allow it to dry.
- Do not place your hearing aids or the batteries on, or too close to, a heat source and do not leave them in direct sunlight.
- Heat exposure and humid environments such as a bathroom will shorten battery life.
- Keep track of how long the batteries are powering your device. If you find that this has shortened recently, there may be an issue with the hearing device and it may need to be repaired. Contact your hearing health care professional to check everything is working as it should.
Where to purchase hearing aid batteries:
- Online retailers
- Electronic stores
- From your audiologist or hearing specialist
How do I know when I should change my hearing aid battery?
- If sound becomes distorted or you find yourself increasing the volume on your device more than usual.
- Some devices have an alarm to signal that the battery needs to be changed. This is usually a beeping sound.
- Hearing aid batteries can lose power suddenly which can significantly interrupt your day, it is recommended to carry an extra set of batteries with you in a secure place.
- Leaving dead batteries in the device for too long can cause them to swell and become difficult to remove.
Rechargeable hearing aid batteries
Zinc-air batteries are usually the first choice for hearing aids as they are cheaper to produce than lithium-ion batteries, store more energy, are safer and more environmentally friendly in the elements that are used.
However, one big negative is the fact that they are complicated to recharge. Researchers at the University of Sydney have recently discovered a solution and are working towards this becoming a mainstream option, so there may be many more rechargeable batteries available for your hearing aid in the near future.
The advantages of rechargeable hearing aid batteries are the benefit to the environment, the ease of use and the fact you don’t need to remember to purchase batteries continually.
Starkey has released a Silver-Zinc battery that gives you 24 hours of power on a 4-hour charge and will last about one year. One benefit of this battery is that you can easily swap it out with a regular disposable zinc-air battery if you forget to charge it.
The cost of purchasing a rechargeable battery set up is comparable to buying around 100 traditional hearing aid batteries, but remember you will have to replace the battery every 1-3 years.
However, rechargeable batteries are not suitable for all types of hearing aids. If you have an older model or are unsure, contact your hearing healthcare provider to check if you can purchase a rechargeable battery pack for your specific aids.
There are also rechargeable hearing aids on the market today which have the batteries built into them.
If you suspect you have a hearing loss, or are considering changing your current hearing aids and need an updated audiogram, click here to book a free hearing test now.