SR (Silver Oxide Battery)/LR (LR Button Battery)
Features (SR: Silver Oxide Battery)
Stable discharge characteristics
A discharge curve during discharge supplies a stable voltage until the end of the discharge life.
High-energy density
A silver oxide battery’s high-energy density per unit volume provides approx. twice the amount of energy capacity as button-type alkaline batteries.
Excellent discharge load characteristics
Alkaline electrolyte is used to provide excellent discharge load characteristics. Depending on the composition of the electrolyte, two models are available; a low-drain type (SW type) for analog watches and a high-drain type (W type) for multi-function watches (which incorporate an alarm and a light), medical equipment, etc.
Superior leakage* resistance
Featuring Maxell's original leak-resistant processing, the SR battery has excellent leakage resistance, which suppresses the electrolyte from rising up and seeping out — a basic phenomenon of alkaline electrolytes.
(* Leakage is defined as an unintended escape of liquid from a battery.)
Taking environment in consideration
As one of its measures to reduce the environmental impact, Maxell draws upon its original technology to realize longer-lasting, superior leakage-resistant characteristics without using mercury and lead.
Applications
SR: Silver Oxide Battery
- -Analog watches
- -Digital watches
- -Measuring instruments
- -Calculators
- -Medical instruments
- -BLE devices
LR: LR Button Battery
- -Toys
- -LED lights
- -Crime prevention buzzers
- -Medical thermometers
Specifications
* Nominal capacity indicates the duration until the voltage drops to 1.2V when discharged at a nominal discharge current at 20 deg. C.
・This product conforms to EU Battery Directive. Mercury is not intentionally added to materials during manufacture.
- Data and dimensions are not guaranteed. For further details, please contact us at your nearest Maxell office.
- Contents on this website are subject to change without notice.
Construction (SR: Silver Oxide Battery)

Principle and reaction
The button-type silver oxide battery uses silver oxide (Ag2O) as its positive active material and zinc (Zn) as its negative active material. Potassium hydroxide (KOH) (W-type) or sodium hydroxide (NaOH) (SW-type) is used as an electrolyte.
Positive reaction : | Ag2O+H2O+2e- → 2Ag+2OH- |
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Negative reaction : | Zn+2OH- → ZnO+H2O+2e- |
Total reaction : | Ag2O+Zn → 2Ag+ZnO |
Total reaction : | 2MnO2+Zn+H2O → 2MnOOH+ZnO |
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Safety precautions
If misused, this battery may deform, leak (the liquid inside the battery may leak to the outside), generate heat, explode, or ignite.
Since such misuse may cause injury or equipment failure, please be sure to read and observe [Warnings and Cautions].