Had a brief flight today in my normal location which is open meadows. After just a few brief moments I saw a 'critical voltage error' message and the phantom immediately started to land. Having rebooted and trying again, the same message was displayed. The battery was around 54% and has only had 40 flights or so. I noted a few days ago that my battery live indicator, had dropped from 100% to 93%. Today that has dropped now to 89%. Having discharged the battery to 10% and recharging the battery fully, the battery report screen in DJI GO, it indicates the following for the cells: 4.25v, 4.31v, 4.28v, 4.31v. Any thoughts on what the issue might be great fully received. The battery has been discharged several times and the auto discharge is set for three days.