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Views: 0 Author: Site Editor Publish Time: 2026-11-07 Origin: Site
Silver oxide coin cells, also widely known as watch batteries, are disposable primary batteries with zinc anode and silver oxide cathode. The standout feature is its steady 1.55V output, which makes it the preferred power source for precision devices. Compared with alkaline coin cells of the same size, silver oxide versions deliver higher capacity and a much smoother discharge curve. It belongs to the SR family and is not interchangeable with CR lithium, LR alkaline or LIR rechargeable coin cells without circuit verification.
When discharging, zinc at the anode releases electrons and is oxidized. Electrons flow through the external circuit to power your device. Inside the sealed cell, silver oxide at the cathode receives electrons and reacts with zinc ions. This reaction cannot be reversed. Silver oxide coin cells cannot be charged. Attempting charging will generate internal gas, trigger leakage and create safety hazards.
Silver oxide coin cells run at a fixed nominal voltage of 1.55V. This is the easiest way to tell it apart from 1.5V alkaline LR batteries.
SR cells hold more energy than equivalently sized alkaline cells. Capacities are small by design, built for low-drain continuous loads rather than high-power output.
Its greatest strength is an extremely flat discharge profile. Voltage stays nearly unchanged until most energy is consumed, which is critical for precision electronics.
Quality silver oxide cells maintain stable performance for 3–7 years under proper storage, with lower self-discharge than standard alkaline batteries.
The standard end-of-discharge cut-off voltage is 1.2V. Once the voltage drops below this point, precision equipment will lose accuracy or stop functioning.
SR is the IEC designated prefix for silver oxide round coin cells. The numbers after SR indicate dimensions, and suffix letters define drain type:
SW: Low drain, optimized for quartz watches
PW: High drain, for devices with periodic pulse current
Example: SR626SW
626 = 6.8 mm diameter, 2.6 mm thickness
SW = low drain watch grade
Model | Diameter | Thickness | Nominal Voltage | Typical Capacity | Drain Grade |
|---|---|---|---|---|---|
SR44 | 11.6 mm | 5.4 mm | 1.55V | 160–180 mAh | Medium drain |
SR626SW | 6.8 mm | 2.6 mm | 1.55V | 26–30 mAh | Low drain |
SR621SW | 6.8 mm | 2.1 mm | 1.55V | 18–22 mAh | Low drain |
SR920SW | 9.5 mm | 2.0 mm | 1.55V | 30–34 mAh | Low drain |
SR927SW | 9.5 mm | 2.7 mm | 1.55V | 38–42 mAh | Low drain |
Battery Type | Nominal Voltage | Rechargeable | Core Advantages | Typical Model |
|---|---|---|---|---|
SR Silver Oxide | 1.55V | No | Ultra-stable voltage, flat discharge curve for precision devices | SR626SW, SR44 |
LR Alkaline | 1.5V | No | Low cost, obvious voltage drop during use | LR44, LR626 |
CR LiMnO₂ Lithium | 3.0V | No | Extra-long shelf life, good low-temperature performance | CR2032, CR2025 |
LIR Lithium-ion | 3.7V | Yes | Rechargeable, higher self-discharge rate | LIR2032 |
Suggested image: Comparison infographic with simple icons, highlight voltage difference between SR and LR
Silver oxide batteries deliver the flattest voltage curve among all 1.5V-class coin cells. The voltage barely declines until the battery is nearly exhausted. Recommended operating temperature: -10℃ ~ +50℃. It works reliably for indoor wearable precision products, but cold resistance is inferior to CR lithium coin cells. ⚠️ Note: Not suitable for continuous high-current or heavy pulse load.
Analog quartz watches and luxury watch movements
Digital calipers, micrometers and precision measuring tools
Portable medical measuring instruments
Mini calculators, small timers
Tiny decorative LED ornaments and compact electronic toys
Precision sensor modules requiring stable 1.55V power supply
Silver oxide coin cells are non-rechargeable. Never charge them.
Avoid short circuit, piercing, squeezing, disassembling or burning.
Keep away from children. Swallowing coin cells can cause fatal internal injury.
Do not mix silver oxide, alkaline or lithium batteries in one device.
Stop using immediately if leakage, strange smell or swelling appears.
Store in cool, dry, dark conditions, away from high heat and humidity.
Export shipments must satisfy CE, RoHS, UN38.3 and MSDS requirements.
Check the original model printed on the old battery first.
Confirm voltage: SR outputs 1.55V, cannot replace 3.0V CR or 3.7V LIR cells.
Verify diameter and thickness to fit the battery holder.
Match drain grade: SW low drain for watches; PW medium/high drain for measuring tools.
Check the operating temperature range of your end product.
Prepare required certificates for your target market.
They share identical dimensions. SR44 is 1.55V and LR44 is 1.5V. It may temporarily power the device, but LR44 cannot maintain stable voltage for precision watches.
SW = low drain for watches; PW = high drain version for products with higher pulse current demand.
Generally 2–4 years. Watches with backlight or extra functions consume power faster.
No. The voltage gap is too large. It will not work and may damage your circuit board.
High-quality silver oxide cells adopt reliable sealing structures. Leakage rarely occurs under normal usage conditions.
NACCON supplies standard silver oxide coin cells and custom SR battery packs for global buyers. We offer solder tabs, wire leads, connector soldering, PCB assembly and customized packaging. Complete certification documents including UN38.3, MSDS, CE and RoHS are available. If you need custom silver oxide battery solutions, send us your requirements: battery model, capacity, drain demand, tab/wire request, dimension limit, working temperature and certification standard.
