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.
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.
There can be several reasons why the appliance doesn't work. The battery can be wrongly inserted in the battery compartment, there can be a bad connection between the battery and the compartment connection terminal or it is possible the appliance does not work properly.