Extending the Life of Hearing Aid Batteries
Most hearing aids on the market today are powered by disposable zinc-air batteries. For hearing aids to work properly, wearers need to replace their zinc-air batteries regularly, which can be quite costly over time. In this article, we will discuss how to extend the life and get the best performance from zinc-air hearing aid batteries.
Why do hearing aids use zinc-air batteries?
There are two main reasons why zinc-air batteries are used in hearing aids. Firstly, they have high energy density. As hearing aids are designed to be small and discreet; it is important that they use batteries that are also small, but with enough capacity to run the hearing aid. The energy requirements of a hearing aid far exceed that of other body-worn devices such as watches. The second reason is that zinc-air batteries are relatively inexpensive to produce. Given that zinc-air batteries often need to be replaced weekly, this is an important consideration.
Currently there are four main sizes of zinc-air button-sized batteries on the market. These batteries have a coloured sticker tab which represents the size of the battery. These sizes and colour coding are standard in the industry. The most common size used globally is size 312 (brown).
How do zinc-air batteries work?
Zinc-air batteries work differently from traditional AA or AAA batteries that may be lying around the house. Not only as they much smaller, being “button” sized, they have a different battery chemistry that requires air to operate. They work by oxidizing zinc with oxygen from the air.
You will notice that all zinc-air batteries have four fine holes on their positive side for this purpose. Oxygen slowly passes through these holes once the sticker tab is removed. As air enters the holes on the battery’s surface, the battery generates its power (see picture).
Optimising the performance of zinc-air batteries
There are several things you can do the optimise the lifespan of your zinc-air batteries.
Firstly, only use fresh batteries, i.e. ensure batteries are used within their “use by” date. Fortunately zinc–air batteries have a long shelf life if sealed to keep air out. They can be stored for up to 3 years at room temperature with little capacity loss if their seal is not removed. The performance of zinc-air batteries degrades significantly if past their use-by date.
Secondly, allow enough “air up” time. After the sticker tab is removed, allow the battery to sit for one minute before inserting the battery into the hearing aid. This allows enough time for air to get into the battery. Taking the tab off and immediately putting the battery in the hearing aid, limits the amount of air it is exposed to. The consequence of this is that the battery may not work properly, as the voltage has not reached a level sufficient to power the hearing aid’s digital circuit. If this happens, allow air to enter the battery (increasing its voltage) by opening the battery door. After one minute, close the battery door.
Battery Life Expectancy
The expected life of a hearing aid battery in days, can have high variability depending on how often the hearing aids are used, the wearer’s hearing loss and what hearing aid features are being used (for example, Bluetooth streaming uses a lot of power).
Size 10: 3 – 10 days
Size 312: 3 – 12 days
Size 13: 6 – 14 days
Size 675: 9 – 20 days
For hearing aid wearers that like to test their hearing aid batteries, please be aware that although the package states a specific voltage (e.g. 1.45 volts), the tabbed voltage will be much lower (e.g. 1.1 – 1.3 volts). After un-tabbing, voltage will rise enough to power a hearing aid. The cell may need several hours to rise to maximum voltage.
Best Value Hearing Aid Batteries in Australia
At Sounds of Life we offer the best value hearing aid batteries in Australia.
Check out our great prices on the premium Power One batteries. We offer special bulk pricing of $27.50 for ten cards (sixty batteries).
Batteries can be ordered directly from our website with free postage.
Australia’s top-selling hearing aid battery brand, Power One is manufactured in the world’s largest and most up-to-date hearing aid battery plant in Ellwangen, Germany. Power One batteries offer the highest quality and reliability, with an extremely long lifespan.
If you feel hearing loss is impacting your life contact Sounds of Life.
Contact us today on 1300 744 432 or via our contact form below:
About Sounds of Life
Sounds of Life Audiology is a leading, independent hearing aid specialist. We offer transparent and affordable hearing aid pricing on quality hearing aids (including virtually invisible hearing aid technology) from the world’s leading brands.