It is quite often that I have patients who come to their hearing aid appointments with a box full of hearing aid batteries that are expired and want to know if they can still use the batteries. Each battery pack has an expiration date or shelf life printed on the back of it.
Do Hearing Aid Batteries Expire? Each zinc air battery manufacturer does print an expiration date on the package of each battery. This date tells you when you should use the hearing aid battery by to expect a full life span it. The
Knowing just a little bit of information about hearing aid batteries can save you a lot of money over the life span of your hearing aid. I have done quite a bit of research on hearing aid batteries which I will share with you.
Can you use a hearing aid battery past its printed expiration date?
You can use a hearing aid battery after it expired however you should not expect to get the length of time out of the battery as one that is freshly made. For example, if you typically get 7 days of use out of each zinc-air battery that you use, after it has expired by 6 months you might get the full life of 7 days or possibly get half (3.5 days).
If it expired a few years ago you may get a full life or it could be completely dead as soon as it is removed from the package. So if you are going to run the risk of using an expired battery, it would be wise to have a spare set of fresh batteries on hand in case your battery unexpectedly dies.
Why do hearing aid batteries expire?
The chemistry that makes up a zinc-air battery is unique, the oxygen in the air is the active ingredient that the battery uses to produce electricity. This is why batteries come packaged with a sticker that covers the air cell ports on top of the battery. To activate a battery, a consumer removes the sticker and the battery comes to life.
The sticker is what prevents a battery from discharging its electrical potential early but it is also the weak point of the system. Over time the adhesive of the sticker can weaken and allow air to enter the battery. As soon as the battery is activated the chemical reaction cannot be stopped or reverted.
Hearing aid batteries expire because the adhesive of the sticker will eventually let air inside the battery cell and drain the battery. Often, with expired batteries, certain cells got air and some cells did not get air to them meaning that some battery cells are still full of energy while others are drained.
The manufacturer puts expiration dates on the batteries because they can only guarantee so much time before air might find a way into a battery cell.
Are Expired Batteries Safe to Use?
Go ahead and used an expired battery and see what happens. You may be lucky and it lasts a long time for you or you may be unlucky and it dies quickly on you.
There is no personal safety risk in using an expired battery.
The risk that you run is that the hearing aids will stop working on you until you insert another fresh battery.
Another risk is that the hearing aid’s advanced functions, such as streaming, may be intermittent. Streaming to the hearing aid via a Bluetooth device takes a lot of power and voltage. If one or more of the hearing aid cells are spent, the battery cannot provide enough current for the feature and it may make the hearing aid intermittent.
Both of those risks are quite low as they will cause no damage to the hearing aids or your ears. The only real potential problem is you being possibly annoyed by having to replace the battery at an inconvenient time.
Should You Buy Expired Batteries or Batteries Close to The Expiration Date?
Often people will sell batteries that have almost passed their expiration date or have already expired on eBay or another discount website for a pretty cheap price. It would be a gamble to buy them. They might work perfectly…or not. The choice is up to you. I personally would buy the newest batteries possible in the store where I can personally check the expiration date.
I am totally for using the expired battery that I found in the drawer in my house that I already own but I do not think it would be worth the risk to buy batteries that were already expired.
Do other types of hearing aid batteries expire?
By far and away the most common type of hearing aid battery is the zinc-air battery but newer rechargeable hearing aids have entered the market. Let’s go ahead and take a closer look at three other types of rechargeable hearing aid batteries.
NiMH or Nickel-metal-hydride batteries were popular rechargeable batteries mainly used in Siemens hearing aids prior to 2018. These batteries do have expiration dates on the back of the packages similar to the zinc-air batteries. However, with these batteries, it isn’t that the air cells are going to die in them but that the length of time that the battery lasts in a day will be shorter. For example, with an expired NiMH battery instead of getting a full day of use out of a full charge, you may only get 6 hours out of a full charge. So, this rechargeable battery is essentially useless if you do plan to use your hearing aid all day as most hearing aid users do.
Silver-Zinc or Z-Power batteries were new to the hearing aid market in 2017 and made a strong run at the beginning of 2018. The advantage of this hearing aid battery is that an audiologist can convert basically any hearing aid into a rechargeable hearing aid. Each battery is designed to last 1 year of use before it is to be replaced. Batteries do not carry expiration dates but their normal shelf life is 5 years. After 5 years the batteries can become hazardous at the onset of leakage.
Lithium-ion Batteries are the newest and most popular of rechargeable hearing aid batteries on the market. Unlike other hearing aid batteries, they cannot be removed from the hearing aid. This is due to their toxic nature. To ensure that no one and no pet swallows one of these batteries (see more info about swallowing any hearing aid battery) they are fully enclosed within the hearing aid. They do not carry an expiration date on them. Hearing aid manufacturers believe that they will last 4-5 years inside of a hearing aid before needing to be replaced.
Related Questions
How often do hearing aid batteries need to be replaced? A size 13 battery should last 7-9 days. A size 312 battery for 5-7 days. A size 10 battery for 3-5 days. However, the length of time a battery lasts depends on how severe the hearing loss is, the length of time used per day, and how much streaming is being done on the hearing aid.\
How can I make my hearing aid batteries last longer? When a battery is first removed from the sticker it takes about 2 minutes for it to fully activate. Wait 2 minutes before putting it into your hearing aid. By doing this you may get an extra day out of the battery. Store batteries at room temperature and not touching another metal object.
Why do hearing aid batteries die so quickly? Hearing aids are like fancy computers processing 100,000 commands a second but run off of only 1.4 volts. As hearing aids get better, they use more electricity which makes the batteries run out even faster. Combine this with the small size, and you get a short usage of a hearing aid battery.