Hearing Aid Battery Size 675, Power One, 60 Pcs Hearing aid batteries are an important consideration for anyone looking to purchase a new pair of hearing aids. If you are new to the world of hearing aids, you’re probably asking yourself the following questions: How long can you expect hearing aid batteries to last? How much will hearing aid batteries cost? Are some hearing aids better than others when it comes to battery life? Does wireless audio streaming impact battery life? Background: Hearing Aid Battery Current Drain. Hearing aid manufacturers have long provided information about their products’ battery usage in the “datasheets” that cover the technical specifications of each hearing aid. As an example, Resounds datasheet for the Resound LiNX2 LS61 shows that the hearing aid (which uses a size 312 battery) drains 1.3 mili-Amps (mA) from the battery when tested in “test mode” via the ANSI S3.22 standard. In theory, it should be easy to estimate the expected battery life of the hearing aid. Given that a size 312 battery has a capacity of 145 mili-Amp-hours (mAh), one merely divides 145 mAh by 1.3 mA to arrive at an estimated battery life of 111.5 hours. Zinc–air batteries, and zinc–air fuel cells are metal-air batteries powered by oxidizing zinc with oxygen from the air. These batteries have high energy densities and are relatively inexpensive to produce.