SR41 Batteries (392/384): How to Choose the Right Button Cell

SR41 batteries are 7.9 × 3.6 mm silver‑oxide button cells that supply a steady 1.55 V for precision devices. This category page explains how to pick the correct SR41 type, what it fits, and when to choose silver oxide over alkaline LR41.

Quick facts

• Size: 7.9 mm diameter × 3.6 mm height (IEC code: SR736)
• Chemistry: Silver oxide (Zn/Ag2O)
• Nominal voltage: 1.55 V (stable output over most of the discharge)
• Typical capacity: ~38–45 mAh (varies by brand and drain type)
• Operating range: about −10 °C to +60 °C
• Common codes: SR41, SR736, 392 (SR41W, high drain), 384 (SR41SW, low drain)
• Alkaline look‑alike: LR41/AG3/192 (same size, lower capacity, less stable voltage)

How to choose within the SR41 category

1) Match the drain type to your device

• Analog watches (steady, low current): choose SR41SW / 384 (low drain).
• Digital watches, alarms, LEDs, or devices with variable loads: choose SR41W / 392 (high drain).
• If your device lists only “SR41” or “392/384,” a high‑drain 392 generally works in place of 384, but not always the other way around in high‑load devices.

2) Prefer silver oxide over alkaline when accuracy matters

Silver oxide (SR41) maintains a flatter 1.55 V curve and typically runs longer than alkaline LR41. Use SR41 for watches, measuring tools, and any device that specifies 392/384 for reliable readings and timekeeping.

3) Check labeling and packaging

• Look for mercury‑free silver‑oxide cells (common from major brands).
• Buy recent stock and avoid damaged packaging; check use‑by or date code.
• Order single packs for a one‑off replacement or multi‑packs for routine maintenance.

SR41 vs LR41 (alkaline) at a glance

Feature	SR41 (Silver Oxide)	LR41 (Alkaline)
Nominal voltage	1.55 V (stable)	1.5 V (drops steadily)
Typical capacity	~38–45 mAh	~25–32 mAh
Best for	Watches, precision instruments, variable loads	Toys, small gadgets with low precision needs
Temperature performance	Better	Fair
Cost	Higher	Lower

Cross‑reference and compatibility

• Silver‑oxide equivalents: SR41, SR736, 392 (SR41W), 384 (SR41SW)
• Brand codes often seen: E392/384 (Energizer), SR41W/SW (Maxell), V392/V384 (Varta), Renata 392/384
• Alkaline equivalents (same size, different chemistry): LR41, AG3, 192
• Only use the size your device specifies (7.9 × 3.6 mm). Do not stack cells or mix chemistries in multi‑cell devices.

Expected runtime

• Analog quartz watch: typically 2–3 years (low‑drain 384)
• Digital watch with alarms/LED: about 1–2 years (high‑drain 392)
• Small instruments labeled for 392/384: months to years depending on use and load

Simple estimate: runtime (hours) ≈ capacity (mAh) ÷ device current (mA). Example: a 0.2 mA load with a 40 mAh cell ≈ 200 hours of continuous operation.

Storage and handling

• Store unopened cells in a cool, dry place (about 50–77 °F / 10–25 °C).
• Keep in original packaging to prevent shorting; avoid heat and humidity.
• Do not mix old and new batteries or different chemistries in the same device.

Safety and disposal

• Button cells are a choking and ingestion hazard. Keep away from children and pets.
• If swallowed, seek immediate medical attention or contact Poison Control.
• Recycle depleted silver‑oxide cells at battery collection points; do not throw in household trash.

FAQ

Are SR41 and 392 the same?

Yes. 392 is a common high‑drain code for SR41; 384 is the low‑drain variant. All are 7.9 × 3.6 mm silver‑oxide cells.

Can I replace LR41 with SR41?

Yes, if the device fits SR41/392/384. SR41 usually lasts longer and holds voltage steadier. Always match the size and observe polarity.

Are SR41 batteries rechargeable?

No. SR41 cells are single‑use silver‑oxide batteries. Do not attempt to recharge them.

Which side faces up when installing?

Most devices place the flat + side facing up, but always follow the polarity markings inside your device.

What if my device lists both 392 and 384?

Use the type recommended by the manufacturer. If unspecified, a high‑drain 392 typically works across a wider range of loads.