Size 312 hearing aid battery
The most widely used hearing aid battery worldwide. Brown tab, 7.9 mm diameter, 3.6 mm height, ~175 mAh capacity. IEC code: PR41.
Specifications
| Property | Value |
|---|---|
| IEC designation | PR41 |
| Tab color | Brown |
| Chemistry | Zinc-air |
| Nominal voltage | 1.45 V |
| Diameter | 7.9 mm |
| Height | 3.6 mm |
| Typical capacity | ~175 mAh |
| Typical runtime | 3–10 days depending on aid style and usage |
| Shelf life (with tab) | 3–4 years |
Compatible devices
- Receiver-in-canal (RIC/RITE) hearing aids — the most common modern style
- Mini behind-the-ear (mini BTE) aids
- Some in-the-canal (ITC) aids
How to identify it
Look for the brown plastic tab covering air holes on the flat face. The size "312" or "PR41" may be printed on the battery face. It is the same diameter as the Size 13 but noticeably thinner (3.6 mm vs 5.4 mm).
Activation
Peel the brown tab fully and wait 60–120 seconds before inserting into the hearing aid. The rest period allows oxygen to saturate the zinc electrode, which measurably improves initial performance and total runtime.
Common mistakes
- Inserting immediately after removing the tab — skipping the rest period reduces run time by up to 20%.
- Confusing 312 with Size 13 — both are 7.9 mm wide. Check the height: 312 is thinner. See the 312 vs 13 comparison.
- Storing with tab removed — once exposed to air, the battery is live and will drain within days.
Buy Size 312 batteries
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