Q: I was fitted with hearing aids that are rechargeable, but they only last a few hours before they go dead. Why does this happen?
A: The short answer is that rechargeable technology is still somewhat in it’s infancy. There used to be two different manufacturers that offered rechargeable hearing systems, Beltone and Siemens. In the last few years Beltone has opted to drop the rechargeable option, mostly due to complaints like this, and the cost to replace batteries. At the time the only material available was what we call NiCd, nickel cadmium batteries, and as many of you will know they have a “memory” attached to them. What that means is that if you don’t let them run until they are completely dead, they will remember that and treat that level as the level of being dead – the long term result is that they go dead faster than they did the previous time you charged it.
Siemens went on to use development of the NiMH, nickel metal hydride rechargeable battery. This material has no issues with memory, and generally has a very predictable life cycle. Generally a size 312 NiMH battery will last a little over a year, at which point the time between charges will start to diminish quite rapidly, eventually to the point where you would need to recharge it every few hours. However, there have been many cases where the battery doesn’t last over a year, but instead goes dead within a few months, such was the case this week. To prevent this from being a problem, Siemens has a one year warranty on the batteries, so if they are rendered unrechargeable within that time frame, they are replaced usually within a few days.
Rechargeable seems like a good idea, in general, but there are some drawbacks. For example, if you go on a holiday, sticking with rechargeable batteries means carrying the charger with you. Fortunately there is the option to revert back to the zinc-air batteries, which, conveniently, fit the same hearing aids. Actually the #312 rechargeable was made to replace the regular battery, so it’s no real surprise that it fits.
Then there are those times that the charger doesn’t work properly and halfway through the day your hearing aids go dead. This is somewhat more common than the battery itself going dead. There have been a few issues with the chargers, most of which have been corrected, but occasionally the contacts in either the hearing aid or the charger don’t quite make contact, or slip off the contact, and you have a less than fully charged hearing aid the next day. It’s inconvenient, and the best thing to do is find somewhere that sells hearing aid batteries, but again, it’s not always an option.
The best piece of advice I can offer is to keep a pair of zinc-air (standard), batteries of the appropriate size in a case near you at all times. We have little carrier cases that hold two and are very small, that you can easily carry in a pocket or purse. I have a friend who keeps two in his wallet, creating the strangest looking indentations in the leather. This way you’re never stuck, you can always hear when you need to.
As for my opinion on whether rechargeables are worth the trouble, it really depends on your lifestyle. If you someone who travel a lot, or would forget to charge them, or even if you keep irregular hours, I would tend to stay with the standard batteries. If you only venture away from home occasionally, or have two homes, (this would probably require keeping an extra charger), or a cottage, then it certainly is more convenient to simply put them in there overnight and know exactly where they are the next morning, and what to expect as far as daily use.
If you need a key fob to store extra batteries in, come in and see us, we have a few extras lying around.