Generally, most modern Gruen watches use standard watch batteries. These batteries are small and circular in shape, and are commonly referred to as "button batteries" or "coin cells". The size and type of battery required for your watch will be specified in the watch's user manual or on the battery compartment itself.
Some common watch battery sizes that may be used in Gruen watches include:
* SR626SW: This is a silver-oxide button battery with a diameter of 6.8mm and a thickness of 2.6mm. It provides 1.55 volts of power.
* LR41: This is an alkaline button battery with a diameter of 7.9mm and a thickness of 4.1mm. It provides 1.5 volts of power.
* 377: This is a mercury-oxide button battery with a diameter of 9.5mm and a thickness of 3.6mm. It provides 1.35 volts of power.
To replace the battery in your Gruen watch, it's recommended to consult the watch's user manual or seek professional assistance from a watch repair service. Improper handling or installation can damage the watch movement, so it's best to leave battery replacement to someone experienced in watch repair.
