The dynabook satellite pro current battery capacity changes erratically from 79% to 19% on different days and so off power lasts between 3 hours to 20 minutes. Original Capacity in 2020 was 45600 and today it is 8800 mWh. Last week it read 51%. I have tried resetting it and am thinking a new generic battery is proper or else a new laptop. It is the inconsistent reading that confuses me. Had it been constantly at 19% day in day out then that tells me it is finished.