Rechargeable Technology at the Tipping Point — It’s Time to Dispose of Disposable Hearing Aid Batteries

This article is brought to you thanks to the sponsorship of ZPower, a company dedicated to building better rechargeable battery technology for hearing aids.

Anyone who owns a cellphone can’t be faulted for assuming most hearing aids are powered by rechargeable batteries. You don’t have to buy a new disposable battery and throw out the old one every time your cellphone battery dies, do you? Of course not – you plug your phone in at night and simply recharge it for another day of use.

Like your mobile phone, hearing aids are products many people use all day, every day. The majority of people don’t sleep with their hearing aids turned on. Why not simply recharge them at night right next to your phone?

If you assumed most hearing aids use rechargeable batteries, you’d be wrong. In fact, only a small percentage of the hearing aids sold each year use rechargeable batteries. That’s bad news for both your pocket book and the planet.

The good news is that new technology, originally developed by NASA and the Department of Defense, is delivering a solution that finally makes rechargeable hearing aid batteries more practical and cost effective than disposable batteries.

What’s the Problem?

The hearing industry and hearing aid users certainly aren’t in love with disposable batteries.

For one thing, disposables have to be changed frequently. They may last a week or more in low-power hearing aids for mild hearing loss, but for super-power hearing aids for severe hearing loss, they may only last several days. Worse, streaming audio and other advanced hearing aid features drain even more power, shortening battery life further. So at a cost of approximately a dollar a piece, batteries for a pair of hearing aids can set you back $100 a year or quite a bit more.

Further, disposable hearing aid batteries are full of toxins and should be recycled, but often they are not. What’s the result? More than 1.4 billion hearing-aid batteries are dumped into the global waste stream every year.

Space-Age Technology to the Rescue

Why, then, do so many hearing aids use disposable batteries? Because, until recently, rechargeable hearing aid technology couldn’t deliver quite enough power in a small enough package to make it through the day.

A modern high-performance hearing aid packs a lot of performance into a very small package. Powerful digital signal processing chips provide sophisticated feedback canceling, digital noise reduction and multiple programs for a variety of listening environments. Self-adjusting directional microphones seek out the sources of the voices you want to hear. And wireless transceivers stream audio from mobile phones and MP3 players.

All that performance requires a lot of power. So it’s no surprise that one of the industry’s biggest challenges has been to design batteries that are small enough to meet strict size constraints, that delivers enough power to drive multiple digital components, and that can last long enough to avoid the need for constant recharging. In an industry where patients lose their ability to communicate when there is a problem, minimal downtime also has to be a requirement.

Lithium-ion technology is a popular foundation for other rechargeable battery applications – for instance, you’ll find a lithium-ion battery behind the back seat of your Toyota Prius. But the highly flammable electrolyte in lithium-ion batteries requires that they be contained in sealed units, which is problematic for the tiny form factors of hearing aids.

So entrepreneurs in the hearing industry set about finding better ways to deliver rechargeable batteries that could meet the size, power and battery life requirements of hearing aids. They found a solution in a technology that had literally been to the moon and back.

Clearing the “One-Charge-a-Day” Hurdle

Until recently, the standard for rechargeable hearing aid batteries was nickel-metal hydride (NiMH) technology. Unfortunately, NiMH batteries couldn’t last long enough to get over the “one-charge-a-day” hurdle for the new higher performance hearing aids.

When the Department of Defense and NASA discovered that NiMH technology wasn’t useful for certain military and aerospace applications, they searched for another solution. They discovered that using silver oxide as the positive electrode and zinc as the negative electrode in a rechargeable battery solved their power and battery-life problems.

Early implementations of silver-zinc rechargeable batteries were used on the Apollo space missions. In fact, it was newly developed silver-zinc batteries, which held a charge longer and met size constraints more easily, that provided backup power necessary for the damaged Apollo 13 to make it home safely after it circled the moon.

Now, hearing-industry entrepreneurs have managed to develop a more affordable version of silver-zinc technology and design it into rechargeable hearing aid batteries. And it’s proving to be a winning solution: the new silver-zinc rechargeable hearing aid batteries provide nearly twice the energy as NiMH-based rechargeable hearing aid batteries – enough to finally meet the “charge-it-once-a-day” standard.

The ZPower Solution

ZPower is the first to deliver silver-zinc rechargeable batteries for hearing aids. The company has recently integrated its silver-zinc rechargeable batteries with a turnkey recharging system that can be used with many leading manufacturers’ hearing aids.

Finally, many hearing aid users who were getting tired of changing and discarding their old batteries have a solution. Without having to buy new hearing aids, patients can purchase the ZPower Rechargeable System and their hearing care provider can install it for them. Using only one set of rechargeable batteries each year, patients will experience all-day power and simply place their hearing aids in the charger at night. No more opening the battery doors and no more changing batteries.

Patients and providers alike recognize an out-of-this-world technology has arrived.

For more information on ZPower’s new rechargeable hearing aid system, contact us at ZPower (866-364-2909).