1 Piece of SR44 Battery Replacement battery for calipers, indicators and micrometers. SR44 battery is a small, cylindrical, silver oxide button cell battery. These high energy density batteries are also used to power hearing aids, wristwatches, key fobs, other test instruments, and small flashlights. Commonly called coin cell, button batteries or watch batteries, they have a low self-discharge to hold their charge for a long shelf and service life and are thin, circular batteries. These batteries can be discarded when their charge runs out. Keep a few on hand so you have a battery when you need it.