Staff Answer
Sep 03, 2026 - 05:22 PM
The original Olympus OM-1 film camera uses one 1.35-volt PX625 mercury battery for its light meter. Since mercury batteries are no longer manufactured, a WeinCell MRB625 1.35V replacement is recommended for accurate meter readings.
The camera’s shutter operates mechanically without a battery; the battery is only required for the built-in light meter.
