In most of the cases, the reasons for a short running time are not necessarily production faults, but rather:
Environmental influences (e.g. humidity, temperature).
Personal hearing habits have changed (longer period of use per day, higher noise level, new features of the hearing aid are being used).
The hearing aid was in use longer than usual (e.g. night at the theater).
The hearing aid is new, or the type or brand of the hearing aid has changed.
The new hearing aid has additional features that require more energy.
Improper handling can also reduce the running time of the hearing aid battery, e.g.:
The battery tab is removed and activation period as too short. It has to be 2 minutes or more before it is inserted into the hearing aid.
The hearing aid is not switched off over night or after a long period of non-use.
The battery loses capacity due to a short circuit when mishandled (e.g. through contact with metal objects).
The battery is stored in a warm environment (e.g. in parked car in the sun).