1.Check if the metal connector is dirty, try to wipe it softly with dry cloth, paperclip or paper towels. (sweat or humidity may also lead to disconnection )2.Please have the battery case fully charged at the beginning without putting the earbuds in.·Swap the left and right earbuds to charge for a try.·Put the left one in the right side of the case, so does the right earphone, which is put in the left side of the case.·Confirm whether it’s the issue of battery case after operating steps above.   3.Reset could solve many problems occurred.