Hearing Aid Batteries: A Complete Guide

Why Hearing Aid Batteries Matter

Your hearing aids are only as reliable as the batteries that power them. A hearing aid with a flat or failing battery is, in effect, a small piece of plastic sitting silently in your ear — offering no amplification, no speech clarity, and none of the connection to the world around you that you depend on. Yet despite their importance, hearing aid batteries are one of the most overlooked aspects of hearing aid ownership. Many people are unsure which size they need, how long batteries should last, when to change them, or whether switching to rechargeable technology might simplify their daily routine.

In the UK, an estimated 2 million people wear hearing aids, and the vast majority rely on tiny disposable batteries that need replacing every few days to a couple of weeks. Understanding the types, sizes, and best practices for hearing aid batteries can save you frustration, extend your battery life, and ensure your aids are always ready when you need them.

Zinc-Air Batteries: How They Work

The overwhelming majority of hearing aids use zinc-air disposable batteries. Unlike standard alkaline batteries, zinc-air cells use oxygen from the surrounding air as a reactant, which is what allows them to pack a surprisingly large amount of energy into a very small package.

Each zinc-air battery has a coloured adhesive tab covering tiny air holes on the flat side (positive terminal) of the battery. While this tab is in place, no air enters the cell and the battery remains dormant — effectively in storage mode. Once you peel the tab away, air flows through the holes, activates the zinc paste inside, and the battery begins producing electricity. This is a one-way reaction: once the tab is removed, the battery will steadily discharge whether or not it is inside a hearing aid.

This mechanism has an important practical implication: never peel the tab until you are ready to use the battery. Removing the tab "to have it ready" will waste battery life. It also means you cannot reuse a partially drained battery by replacing the tab — once air has entered the cell, the chemical reaction continues regardless.

A widely recommended tip is to peel the tab and then wait 60 seconds before inserting the battery into your hearing aid. This brief pause allows air to fully saturate the zinc-air cell, optimising the chemical reaction from the start. Studies have shown that this simple step can extend overall battery life by up to 10% — a meaningful difference when multiplied across hundreds of battery changes over the life of your hearing aids.

Battery Sizes and Colour Codes

Hearing aid batteries come in four standard sizes, each universally identified by a colour-coded tab. This international colour coding system means that regardless of the manufacturer — whether Rayovac, Duracell, PowerOne, or any other brand — a brown-tabbed battery is always a size 312. The four sizes are:

• Size 10 (yellow tab): The smallest hearing aid battery, measuring just 5.8 mm in diameter and 3.6 mm high. Used in completely-in-canal (CIC) and invisible-in-canal (IIC) hearing aids — the smallest, most discreet styles. Typical lifespan: 3 to 7 days.
• Size 312 (brown tab): Slightly larger at 7.9 mm diameter and 3.6 mm high. The most commonly used size, powering many receiver-in-canal (RIC) and in-the-canal (ITC) hearing aids. Typical lifespan: 3 to 10 days.
• Size 13 (orange tab): Measuring 7.9 mm in diameter and 5.4 mm high. Used in behind-the-ear (BTE) and some in-the-ear (ITE) hearing aids that require more power. Typical lifespan: 6 to 14 days.
• Size 675 (blue tab): The largest standard hearing aid battery at 11.6 mm diameter and 5.4 mm high. Used in powerful BTE hearing aids for severe-to-profound hearing loss and in cochlear implant processors. Typical lifespan: 9 to 20 days.

Actual battery life varies considerably depending on several factors: the power demands of your hearing aid (more amplification means higher current draw), the number of hours per day you wear your aids, how much you use Bluetooth streaming for phone calls and music, the complexity of your hearing aid`s processing features, and environmental conditions such as temperature and humidity. If you are unsure which size your hearing aid requires, check the user manual, the markings on the battery compartment, or ask your audiologist at your next aftercare appointment.

How to Change Hearing Aid Batteries

Changing a hearing aid battery is straightforward, but the small size of both the battery and the battery door can make it fiddly — especially for people with reduced dexterity, arthritis, or visual impairment. Here is a step-by-step approach:

• Step 1: Work over a soft surface such as a towel or bed, so that if you drop the battery or hearing aid, it does not bounce away or get damaged.
• Step 2: Open the battery door fully. On most hearing aids, the door opens with a small fingernail notch. If you have difficulty, a battery-changing magnet tool (available from most audiologists and hearing aid retailers) can make this much easier — these tools have a magnetic tip that lifts the old battery out and positions the new one.
• Step 3: Remove the old battery and dispose of it safely (see disposal section below).
• Step 4: Peel the tab from the new battery and wait 60 seconds.
• Step 5: Place the new battery into the compartment with the flat, positive (+) side facing up. The battery should sit flush. If it does not fit easily, do not force it — check you have the correct size.
• Step 6: Close the battery door gently. If it does not close smoothly, the battery may be inserted incorrectly or you may have the wrong size.

Most modern hearing aids produce a small jingle or tone when powered on with a fresh battery, confirming that the battery is correctly inserted and working. If you do not hear the start-up tone, open the door and check the battery orientation.

Many hearing aid wearers find it helpful to establish a routine — for example, changing batteries every Sunday morning — rather than waiting for them to die unexpectedly. Some hearing aids provide a low-battery warning tone, typically a series of beeps, giving you several hours` notice before the battery is depleted. Carrying a spare pair of batteries in your wallet, handbag, or car glove box ensures you are never caught without power.

Rechargeable Hearing Aids: A Modern Alternative

Rechargeable hearing aids have grown rapidly in popularity over the past several years and are now offered by every major manufacturer, including Phonak, Oticon, Signia, Starkey, ReSound, and Widex. Instead of disposable zinc-air cells, rechargeable aids use a built-in lithium-ion battery — the same technology that powers smartphones and electric vehicles — charged overnight in a dedicated docking station or case.

The advantages of rechargeable hearing aids are significant:

• Convenience: No more fumbling with tiny batteries. Simply place your hearing aids in the charging case each night and they are ready in the morning.
• Dexterity-friendly: Ideal for people with arthritis, tremor, reduced vision, or any condition that makes handling small objects difficult.
• Cost savings over time: While rechargeable hearing aids may have a higher upfront cost, eliminating the ongoing expense of disposable batteries (which can total £50 to £100 per year for a pair of aids) means they often work out more economical in the long run.
• Environmental benefit: A single rechargeable battery replaces hundreds of disposable zinc-air cells over its lifetime, reducing waste.
• Reliable performance: Lithium-ion batteries deliver consistent voltage throughout their charge cycle, meaning sound quality does not fade as the battery runs down — unlike zinc-air batteries, which can produce slightly weaker output towards the end of their life.

A full charge typically provides 18 to 30 hours of use, depending on the hearing aid model and how much Bluetooth streaming you use. Most charging cases deliver a full charge in 3 to 4 hours, and some offer a quick-charge feature that provides several hours of use from just 30 minutes of charging.

Some NHS audiology departments now offer rechargeable hearing aids, though availability varies by region and waiting lists may apply. If you are considering rechargeable aids, discuss the options with your audiologist at your next hearing aid fitting or review appointment. Providers such as Boots Hearingcare, Specsavers Audiology, and Hidden Hearing all offer rechargeable models across their ranges.

Getting Batteries on the NHS

If you have been fitted with NHS hearing aids, you are entitled to receive replacement batteries free of charge from your local NHS audiology department. This is an ongoing entitlement for as long as you use your NHS aids — there is no limit on the number of batteries you can receive, and no time restriction on how long after fitting you can continue to collect them.

Most NHS audiology departments offer several ways to obtain batteries:

• Postal service: Many departments operate a free postal battery service. You request batteries by phone, online form, or email, and they are posted directly to your home. This is the most convenient option for many people, particularly those with mobility issues or who live far from the hospital.
• Collection in person: You can collect batteries from the audiology department reception, often without needing an appointment. Some departments have a battery collection point at the hospital entrance or pharmacy for added convenience.
• Online ordering: An increasing number of NHS trusts now offer battery ordering through patient portals or dedicated web forms.

When requesting batteries, you will typically need your audiology department reference number or patient ID. It is a good idea to order replacement batteries before you run out completely — most departments aim to dispatch within a few working days, but delays can occur during busy periods.

NHS batteries are high-quality zinc-air cells sourced from reputable manufacturers such as Rayovac, PowerOne, and Duracell. They are the same batteries used by private audiologists and are supplied in the same colour-coded packaging, so there is no difference in quality or lifespan compared to batteries you might purchase privately.

Storing Batteries and Maximising Lifespan

Proper storage and good daily habits can make a meaningful difference to how long your hearing aid batteries last. Follow these guidelines to get the best performance:

• Store at room temperature: Keep unused batteries in a cool, dry place — ideally between 10°C and 25°C. Avoid extremes of heat (such as a car dashboard in summer) or cold. Do not refrigerate hearing aid batteries. Despite the common myth that refrigeration extends battery life, the condensation that forms when cold batteries are brought to room temperature can actually damage the zinc-air cells and reduce performance.
• Keep in original packaging: Leave batteries in their sealed blister pack until you need them. The packaging protects the tab seal and prevents accidental activation.
• Avoid contact with metal objects: Loose batteries stored alongside coins, keys, or other metal items can short-circuit, draining their charge or even generating heat. Always store batteries in their packaging or a dedicated battery caddy.
• Open the battery door at night: When you remove your hearing aids at bedtime, open the battery door fully. This does two things: it breaks the circuit so the battery stops draining, and it allows air to circulate inside the hearing aid, helping moisture to escape. Place your aids in a dehumidifier overnight for maximum benefit.
• Minimise unnecessary streaming: Bluetooth streaming for phone calls, music, and television is one of the biggest drains on hearing aid batteries. If battery life is a concern, consider limiting streaming time or using an intermediary streaming device that takes the Bluetooth processing load off the hearing aid.
• Clean battery contacts: Wipe the battery contacts inside the hearing aid with a dry cotton bud or clean cloth periodically. Dirt, moisture, and corrosion on the contacts can impede the electrical connection and cause batteries to drain faster or produce intermittent power.

Properly stored zinc-air batteries have a shelf life of approximately two to three years from the date of manufacture. Check the expiry date on the packaging and use older stock first.

Safe Disposal and Environmental Considerations

Used hearing aid batteries should never be thrown in general household waste. Although zinc-air batteries do not contain mercury (mercury was phased out of hearing aid batteries in the EU by 2015), they still contain zinc and other materials that should be recycled responsibly.

In the UK, used batteries of all types — including hearing aid batteries — can be disposed of at:

• Battery recycling points: Found in most supermarkets, pharmacies, and high-street shops. Look for the battery recycling bin near the entrance or at the customer service desk.
• Local recycling centres (HWRCs): All local authority recycling centres accept used batteries.
• NHS audiology departments: Many departments accept used batteries for recycling when you collect your replacements.
• Hearing aid retailers: Most high-street audiologists, including Boots Hearingcare and Specsavers, accept used batteries for recycling.

Safety warning: Hearing aid batteries are small enough to be swallowed by young children and pets, and ingestion can cause serious internal injuries. Always store batteries out of reach of children, never leave loose batteries on tables or countertops, and seek immediate medical attention if a battery is swallowed. The UK National Poisons Information Service advises going straight to A&E if battery ingestion is suspected.

When to Speak to Your Audiologist

If you notice a sudden or significant drop in battery life, it may not be the batteries themselves that are the problem. Reduced battery life can indicate:

• A fault in the hearing aid`s electronics or a damaged battery contact
• A change in your hearing that has caused the aid to work harder (drawing more power)
• Moisture damage affecting the battery compartment or circuitry
• Ear wax blocking the receiver, causing the hearing aid to increase output to compensate
• Software settings that need adjusting — for example, unnecessarily high volume or active features you do not use

If your batteries are consistently lasting less than expected, or if you are changing batteries more than twice a week with a size 312, book a check-up with your audiologist. They can test the hearing aid`s current draw, inspect for faults, clean internal components, and reprogramme settings if needed. Regular hearing aid aftercare appointments — typically every 6 to 12 months — are the best way to keep your aids performing at their best and to address battery issues before they become a daily frustration.