Renata Batteries

Renata Batteries: precise coin and button cells for watches, medical, and compact electronics

Renata, part of The Swatch Group, manufactures micro batteries designed for predictable voltage and long shelf life. The lineup includes mercury-free silver oxide SR watch cells, 3 V lithium coin CR cells, zinc-air hearing-aid cells, and select custom lithium-polymer packs for OEM applications.

Use Renata if

• You need tight voltage tolerance for quartz movements, medical sensors, or meters.
• Your device specifies SR or CR cells and benefits from leak-resistant construction and low self-discharge.
• You want widely cross-referenced sizes that match IEC and watchmaker codes.

Choose something else if

• You require rechargeable coin cells or multi-cell battery packs with built-in charging protection.
• The device draws high pulsed current beyond what button cells can supply, such as cameras with flash or high-power radios.

Battery types at a glance

Chemistry	Nominal voltage	Common sizes	Best for	Notes
Silver oxide mercury-free	1.55 V	377 SR626SW 6.8 by 2.6 mm, SR44 303 357 11.6 by 5.4 mm, 364 SR621SW	Watches and precision instruments	Flat discharge, low self-discharge. Choose W high-drain vs SW low-drain per device.
Lithium coin MnO2	3.0 V	CR2032 about 220 to 240 mAh, CR2025, CR2016, CR1632	Key fobs, remotes, bike sensors, IoT	Long shelf life, wide temperature range, good leak resistance.
Zinc-air	1.4 to 1.45 V	Hearing-aid sizes 10, 312, 13, 675	Hearing aids and audio devices	Air activated. Remove tab only when ready, then wait 1 to 2 minutes.
Rechargeable lithium-polymer	About 3.7 V	Custom thin packs	Wearables and compact sensors	Requires compatible charging and protection circuitry.

How to pick the right cell

• Match size first. The code encodes dimensions, for example CR2032 is 20 mm by 3.2 mm.
• Match chemistry and voltage. Do not replace SR silver oxide with LR alkaline unless your manual permits it. Keep CR to CR for lithium coin cells.
• For watches, select SW low-drain for simple analog models and W high-drain for chronographs, alarms, or LED features.
• Use cross references to confirm. Examples 377 equals SR626SW, SR44 equals 303 and 357, 364 equals SR621SW.
• Check freshness. Prefer recent date codes and sealed packaging for best shelf life.

Typical runtime and shelf life

• Watches silver oxide about 12 to 36 months depending on movement and complications.
• Hearing aids zinc-air size 10 about 3 to 7 days, 312 about 3 to 10 days, 13 about 6 to 14 days, 675 about 9 to 20 days.
• CR2032 in remotes and key fobs roughly 1 to 3 years, in sensors about 6 to 24 months depending on transmit interval and temperature.
• Sealed shelf life typical silver oxide about 3 to 5 plus years, lithium coin about 5 to 10 years, zinc-air about 2 to 3 years sealed.

Pros and limitations

• Pros stable voltage for precision devices, mercury-free silver oxide, leak-resistant designs, broad size coverage, low self-discharge.
• Limitations zinc-air must be used soon after activation, non-rechargeable cells must not be recharged, high-drain electronics may require rechargeable packs.

Storage, handling, and safety

• Store cool and dry, ideally 10 to 25 degrees C. Keep cells in original packaging until use.
• For zinc-air, do not remove the tab until installation. After removing, wait 1 to 2 minutes before closing the battery door.
• Do not mix old and new cells or different chemistries in the same device.
• Carry spares in a case, not loose in a pocket, to prevent short circuits.
• Button cells are an ingestion hazard. Keep away from children and pets. If swallowed, seek immediate medical help.
• Tape terminals before disposal and follow local recycling guidance.

Alternatives and compatibility notes

• Alkaline button cells LR AG are cheaper but have lower capacity and less stable voltage than silver oxide. Adequate for some remotes or toys, not ideal for precise watches.
• Rechargeable coin cells such as LIR2032 have different voltage and discharge behavior. Use only if the device explicitly supports them.
• Cross-brand replacements are common. Always match size, chemistry, and drain type regardless of brand.

FAQ

Are Renata silver oxide watch cells mercury-free

Yes. Renata silver oxide watch batteries are mercury-free while maintaining a stable 1.55 V output.

Can I replace an LR44 with an SR44 303 357

Often yes. SR44 silver oxide typically offers higher capacity and a flatter discharge than LR44 alkaline. Confirm your device requirements first.

What is the difference between W and SW watch cells

W high-drain supports features like chronographs and alarms. SW low-drain suits simple analog watches. Using the wrong type can reduce runtime.

How do I read CR2032, CR2025, and similar codes

The first two digits are diameter in millimeters and the last two are thickness in tenths of a millimeter. For example, CR2032 is 20 mm by 3.2 mm.

Why did my zinc-air hearing-aid battery drain quickly

Once the tab is removed, air activates the cell and it self-discharges even when not in use. Open only when needed, let it breathe for 1 to 2 minutes before sealing the door, and keep the compartment closed when not in use.