How to Recharge Rechargeable Hearing Aids

How to Recharge Rechargeable Hearing Aids

Hearing aid batteries are stores of energy, not electricity, and they store this potential in ions in virtual racks. This article is about charging rechargeable hearing aids, but first we have some simple science to share.

Electricity occurs when the battery ions flow along electric wires to suitably-matched hearing aids, and empower them to do their work. When the ions are all used up, the batteries are ‘out of juice’ and the hearing aids stop working.

But that’s not necessarily the end of the road for them. We can pop fresh, single-use batteries into them or we can put the ions back into the batteries if they are the rechargeable type.

How Batteries Work: Your ‘101’ for Today

It’s important to understand how batteries work to use them correctly. Those fires in cellphones and electric cars caused a real stir when their owners pushed them to limits. It’s good to know hearing aid batteries use different chemicals that are safe and can’t catch alight.

None the less, it’s important to allow sufficient charging time for rechargeable hearing aids, for reasons we shall explain. But first, it’s back to the 101 classroom, so please form an orderly line like you did when you were kids. We should mention what follows is a simple allegory, because our lift does not stop on the floor of battery science.

Artist's Impression of a Typical Spent Battery with Ions Almost Use Up

Electrons and ions that makeup a hearing aid battery

Source to Credit


All batteries – well cells if you want to be pedantic – have two electrodes that manage the ions, two terminals that connect these to the energy world, and a chemical between the electrodes that acts as ‘gate keeper’ and keeps things under control.


A charged battery has ions full of energy in the negative electrode (cathode). The ions flow through the electrolyte to the positive electrode (anode) when we connect the terminals to the hearing aid. When all the available ions have flowed across, the battery is flat.


Single use batteries are finished, kaput and good for the recycling bin when they are flat, used up and spent. However, rechargeable batteries have different chemistry that allows us to renew them. But first, we need to take a short detour into battery memory, so we understand how to charge rechargeable hearing aids correctly.


A new hearing aid battery has a finite number of charged ions in it, determined by the manufacturer. In simple terms, this sets the charge-life of the battery, and influences price. Some of those ions have not moved across in our image, and the most likely reason is the battery has ‘forgotten’ about them.

Electrodes in rechargeable batteries have upper and lower limits to ion capacity.  This controls the amount of activity in a battery, which generates warmth when we recharge it.

Manufacturers ‘embed memories’ in rechargeable batteries in hearing aids when they manufacture them. However, we can shorten those memories (life between recharges) if we let the batteries run completely flat, or don’t allow them to recharge fully. This may be also be why some ions did not move across in our drawing.

And now here’s some good news. Science lesson is over, and class is out. We can move on our tips for charging rechargeable hearing aids correctly, which is why we are here in the first place.

How to Recharge Rechargeable Hearing Aids

This part of our article is a walk in the park now we know how the science works. In fact, it’s even easier than we may think, because manufacturers include technology that prevents hearing aid batteries from over-charging.

We just need to make sure they don’t go completely flat and allow sufficient charging time for our rechargeable hearing aids so they renew fully. The method is the same regardless of the battery type.


Inspect your hearing aids, and the batteries (if accessible), when they arrive for any damage before using them. Contact the supplier if in any doubt. Charge the batteries overnight for twelve hours if everything checks out.


Start using the hearing aids the following morning. Experiment with the settings until you can hear clearly again. Rejoice in the moment, live the day.


Recharge the hearing aids again that evening while they still have some charge, and overnight so they are full again. Continue doing so until you stop wanting to hear properly again.

Is This Really Worth the Hassle?

You bet it’s worth it, especially if you purchase Blue Angels Hearing Aids. They give your eighteen hours battery life after a single, two-hour charge. They price from $297.99 to $597.99 a pair including batteries, case and accessories. They are ‘child’s play, plug and play devices.

More Information

Contributors to Noise Induced Hearing Loss

Doorbell for Hard of Hearing People

The Science of Batteries and Recharging Them