AnswerSR1120W, 391, V391 are the supported exact aliases for one 11.6 × 2.05 mm silver-oxide watch cell. No other family is treated as an automatic replacement.
Supported application context
- Watches specifying this exact code and drain class
Application context is limited to the scope stated in Murata Watch Battery Selection Guide; it is not a device compatibility claim.
This record belongs to the watch-cell system. Maker numbers are useful aliases, while the W higher-drain designation remains part of device selection.
SR1120W/391 is the higher-drain 11.6 × 2.05 mm record. The nearby 365/366 pair is 0.4 mm thinner and the 389/390 pair is 1.0 mm taller.
Commonly confused
What the code means
SR1120W identifies a silver-oxide watch cell. The W or SW suffix is part of the supported identity and records the manufacturer drain class.
Discharge and drain behaviour
Silver-oxide cells are selected for a comparatively stable working voltage. W: higher-drain profile remains material in watch applications, so a shared diameter and height do not erase the W/SW distinction.
Capacity context: Manufacturer- and test-condition-specific; no universal capacity is asserted from the selection guide.
Substitution guidance
Treat only the aliases on this page as exact equivalents. Another cell with the same dimensions is conditional at best unless its chemistry, nominal voltage and higher-drain requirement also agree with the device specification.