Yesterday, after 1 minute of flight I ´v got the Battery error message. I looked at the battery info and the first cell pictute was empty and 0 Volts. I pushed RTH and phantom reacts normally and turned home. On the second look on screen all four cells were empty with no voltage readings. Phantom came back to me and I howered for a minute, tryied to go full up and everything looked normal. The battery reading was back again on all 4 cells.. Later I looked at the log, the battery showed 100% all the time till the error message. The indicators on the batt changed between normal reading and all 4 leds blinking. In the CSV the first cell dropped to 3, 02 Volts, but then gone to normal level.