Hearing aid batteries come in four standard sizes: 10, 312, 13, and 675. Each size is identified by a universal color-coded tab, so you never have to squint at tiny printed numbers to figure out which one you need. The size your hearing aid requires depends on the style and power demands of your device.
The Four Standard Sizes at a Glance
Every major battery brand uses the same numbering system and the same color coding. Here’s how the four sizes break down:
- Size 10 (yellow tab): 5.8 mm diameter, 3.6 mm height. The smallest standard hearing aid battery, lasting roughly 3 to 7 days.
- Size 312 (brown tab): 7.9 mm diameter, 3.6 mm height. A mid-range option that typically runs for 7 to 10 days.
- Size 13 (orange tab): 7.9 mm diameter, 5.4 mm height. Same width as the 312 but taller, providing 10 to 14 days of use.
- Size 675 (blue tab): 11.6 mm diameter, 5.4 mm height. The largest battery, lasting 14 to 20 days.
All four are tiny by any standard. Even the largest, the 675, is only about the width of a dime and roughly as tall as a pencil eraser. The smallest, the size 10, is closer to the size of a pea. If you ever lose track of which size you need, the color of the tab is the quickest way to confirm: yellow, brown, orange, or blue.
Which Size Fits Which Hearing Aid
The battery size is determined by your hearing aid’s style. Smaller, more discreet devices use smaller batteries, while larger, more powerful models use bigger ones.
Size 10 batteries power the tiniest devices, including completely-in-canal (CIC) and receiver-in-the-ear (RITE) hearing aids. Size 312 covers a broader range: behind-the-ear (BTE), RITE, and in-the-canal (ITC) models all use it. Size 13 is common in BTE and in-the-ear (ITE) hearing aids that need more juice. Size 675 is reserved almost exclusively for high-power BTE devices, the kind often used for severe or profound hearing loss.
Your audiologist or the hearing aid manual will specify exactly which size to buy. You can’t swap one size for another since the battery compartment is molded to fit only the correct dimensions.
How Zinc-Air Batteries Work
Nearly all disposable hearing aid batteries use zinc-air chemistry. They sit dormant on the shelf until you peel off the colored sticker tab on the back. That sticker seals tiny air holes in the battery casing. Once removed, oxygen enters and reacts with the zinc inside, generating power.
This means the clock starts ticking the moment you pull the tab. A practical tip: after removing the tab, wait about five minutes before inserting the battery into your hearing aid. This gives the zinc enough time to fully activate, which can improve overall battery life. Once the tab is off, you can’t deactivate the battery by sticking it back on. The chemical reaction has already begun.
Getting the Most From Each Battery
How long a battery lasts depends on more than just its size. Streaming audio from a phone, using advanced noise-processing features, and wearing your hearing aids for long hours all drain power faster. Someone who wears their size 312 hearing aids 16 hours a day with frequent Bluetooth streaming will burn through batteries faster than someone who wears theirs 8 hours with no streaming.
For storage, keep unused batteries at room temperature, ideally between 50°F and 77°F. Don’t store them in the refrigerator, as condensation can damage the seal. Sealed batteries have a shelf life of at least two years, so buying in bulk is perfectly reasonable as long as you check the expiration date on the package.
When you’re not wearing your hearing aids, open the battery door. This cuts the circuit and stops the drain, and it also lets moisture escape from inside the device.
Rechargeable Hearing Aids vs. Disposable Batteries
Many newer hearing aids, particularly BTE and RITE styles, now come with built-in rechargeable lithium-ion batteries instead of disposable zinc-air cells. You place the hearing aid in a charging dock overnight, and it’s ready the next morning. There’s no tiny battery to fumble with, which is a real advantage for anyone with limited dexterity or poor vision.
The trade-off is flexibility. Rechargeable batteries can’t be swapped out on the go, so if your charge dies mid-day and you’re away from the dock, you’re out of luck until you can recharge. Disposable batteries, on the other hand, let you pop in a fresh one anywhere. Some very small hearing aid styles, like invisible-in-the-ear models, can only run on disposable batteries because there isn’t room for a rechargeable cell and its circuitry.
Safe Disposal
Hearing aid batteries fall under the EPA’s button-cell battery category. Don’t toss them in the regular trash or your curbside recycling bin. Instead, bring spent batteries to a participating retailer with a battery take-back program, a specialized battery recycler, or your local household hazardous waste collection site.
Before disposing of them, place each battery in its own small plastic bag or cover the terminals with a strip of electrical tape. This prevents short circuits that could generate heat. And because these batteries are tiny enough for a small child to swallow, store both fresh and spent batteries well out of reach of kids.