What colour is a size 312 hearing aid battery?

Brown. The colour coding is a universal standard rather than a brand choice, so a brown tab means size 312 whoever made the battery. The four are yellow for size 10, brown for 312, orange for 13 and blue for 675, and checking the colour on the packet is the fastest way to reorder correctly.

How long does a size 312 battery last?

Typically 3 to 10 days, which is a trade rule of thumb rather than a published specification. The range is wide because it depends on how many hours a day the device is worn, how much amplification it is delivering, and whether audio is being streamed from a phone. Streaming is by far the largest single factor and can more than halve the figure.

Why does my battery die faster than it should?

The commonest causes are streaming audio from a phone, which draws roughly twice the current of amplification alone, and removing the tab well before the cell goes into the device. Zinc-air cells begin discharging as soon as air reaches them and replacing the tab does not stop it. A device set to more amplification than it needs also draws more.

Can I use a different size in my hearing aid?

No. The battery compartment is sized for one cell and a different size will not seat correctly, if it fits at all. Sizes 312 and 13 share a diameter and differ only in height, which is the one pair that occasionally gets confused, but a 13 will not close into a 312 compartment. Check the colour on your current packet before reordering.

Should I switch to a rechargeable hearing aid instead?

That depends on dexterity more than on cost. Handling a cell the size of a shirt button every few days is the part people find difficult, and a rechargeable device removes it entirely by replacing it with dropping the aids into a charger each night. The trade-off is that a rechargeable device cannot be revived late in the evening with a spare cell from a drawer.

Size 312 hearing aid batteries

Quick answer

A size 312 hearing aid battery has a brown tab, is designated IEC PR41, measures 7.9 by 3.6 millimetres, runs at 1.45 volts nominal, and typically lasts 3 to 10 days. The colour coding is universal: every manufacturer uses the same colour for the same size.

What is a size 312 hearing aid battery?

Hearing aid batteries come in four sizes, and the number, the tab colour and the IEC designation are a universal published standard. That is genuinely useful: the fastest way to identify which battery a device takes is the colour of the tab on the packet, and it means the same thing whoever made it.

Published figure From a named standards body, regulator or professional classification. Reproduced here, not derived by us.

Size 312 is the brown one, IEC PR41, 7.9 by 3.6 mm.

The four hearing aid battery sizes
Size	Tab colour	IEC	Diameter (mm)	Height (mm)	Typical life (days)
Size 10	Yellow	PR70	5.8	3.6	3 to 7
Size 312	Brown	PR41	7.9	3.6	3 to 10
Size 13	Orange	PR48	7.9	5.4	6 to 14
Size 675	Blue	PR44	11.6	5.4	9 to 20

Size number, tab colour and IEC designation are a universal standard: every maker uses the same colour for the same size, which is why the colour is the fastest way to identify a battery. Zinc-air cells are activated by air, so the tab should be left on until the battery is needed and then given about a minute before the door is closed.

Which devices take this size

The most common size by a wide margin. Most receiver in canal and many in the ear devices.

The relationship is simple: a bigger cell holds more and lasts longer, and a smaller device has room only for a smaller cell. That is the whole trade-off behind the four sizes, and it is why the smallest and least visible devices need their batteries changed most often.

Getting the most out of a zinc-air cell

Zinc-air cells are activated by air reaching them through holes under the tab, which has two practical consequences that account for most of the complaints about battery life.

Leave the tab on until you actually need the cell. Once it comes off, the cell starts discharging whether or not it is in a device, and putting the tab back on does not stop it. Then wait about a minute after removing it before closing the battery door. A cell that has not fully activated reads as weak or dead, and a great many perfectly good batteries are thrown away for exactly this reason.

Storing cells at room temperature rather than in a refrigerator is also worth knowing: the old advice to refrigerate them does not help zinc-air chemistry, and condensation can hurt.

Common questions

What colour is a size 312 hearing aid battery?: Brown. The colour coding is a universal standard rather than a brand choice, so a brown tab means size 312 whoever made the battery. The four are yellow for size 10, brown for 312, orange for 13 and blue for 675, and checking the colour on the packet is the fastest way to reorder correctly.
How long does a size 312 battery last?: Typically 3 to 10 days, which is a trade rule of thumb rather than a published specification. The range is wide because it depends on how many hours a day the device is worn, how much amplification it is delivering, and whether audio is being streamed from a phone. Streaming is by far the largest single factor and can more than halve the figure.
Why does my battery die faster than it should?: The commonest causes are streaming audio from a phone, which draws roughly twice the current of amplification alone, and removing the tab well before the cell goes into the device. Zinc-air cells begin discharging as soon as air reaches them and replacing the tab does not stop it. A device set to more amplification than it needs also draws more.
Can I use a different size in my hearing aid?: No. The battery compartment is sized for one cell and a different size will not seat correctly, if it fits at all. Sizes 312 and 13 share a diameter and differ only in height, which is the one pair that occasionally gets confused, but a 13 will not close into a 312 compartment. Check the colour on your current packet before reordering.
Should I switch to a rechargeable hearing aid instead?: That depends on dexterity more than on cost. Handling a cell the size of a shirt button every few days is the part people find difficult, and a rechargeable device removes it entirely by replacing it with dropping the aids into a charger each night. The trade-off is that a rechargeable device cannot be revived late in the evening with a spare cell from a drawer.

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Last updated 2026-09-17.