The capacity of batteries is indicated as XXXX mAh (milliampere/hour). If you insert this battery into an appliance which consumes 100 milliampere current continuously, the operating time of the appliance will be around 20 hours mathematically.
Batteries will become unfit to use after they’ve been in the water. Usually however, a battery won’t leak inside the washing machine thanks to the safety valve - so chances of your textile being affected are minimal.
Avoid contact with the substance at all times. Place the batteries into a plastic bag before recycling them. Clean out the battery holder with a dry cotton swab. In case of contact, wash your hands thoroughly with soap and water.