Hearing Aid Batteries

Today's Batteries

Nothing is more critical to the success of using a hearing aid than the battery. As you'll see in the section under troubleshooting, many of the difficulties encountered with hearing aids can be directly attributed to batteries. Good battery care is vital with today's electronics that need a constant and dependable source of power.

The quality, life, and size of batteries have changed significantly over the years. In the past mercury and silver were commonly used in hearing aid batteries, today silver is seldom found because of cost and mercury has been dropped due to it's toxicity to the environment.

Today, most batteries are zinc-air. The battery itself contains zinc, which interacts through access holes in the battery with air. These batteries have a long shelf life and are 'activated' by removing the tape seal from the cathode side of the battery. With the zinc-air batteries available today you'll receive clearer tones with fewer volume adjustments.

The Zinc-Air Battery

One of the most significant changes in batteries has been their size, which has allowed the development of smaller hearing aids. A size 675 battery in the past is now replaced with a 312 (1/5th the size), a 10A (1/10th the size) or even the smaller ones like a 5A (1/20th the size). Battery life has increased while battery size has decreased. Another feature of hearing aid batteries is their relatively flat discharge rate measured in milliampere hours (mAh). If you want an approximate life of your battery in hours, take the batteries capacity (mAh) and divide it by the current drain of the hearing aid which is given in milliamperes (mA).

Color Coding System

	Size 5	5	10	312	13	675
	Size 10 (or 230)
	Size 312
	Size 13
	Size 675

The battery life of a hearing aid may be several weeks while your watch is several years. Why? A hearing aid has a number of electrical circuits and even a computer program to run. The power demand on these batteries is 50 to 100 times that of a digital wristwatch. A longer battery life for a hearing aid is possible but it would require a larger battery and therefore a bigger hearing aid.

There's a wide range of hearing aid battery manufacturers in the market, the larger companies being: Rayovac, Energizer, Toshiba, ZeniPower, Duracell, Power One, Renata, and Sony.