They repaired the battery contact. The damage was likely caused when the battery became dislodged in the grip's carriage unit while inside the grip after hours of use.
Interestingly, the exact same dislodging recently occurred in my Nikon grip, though fortunately no damage was done. Yes, I make sure the carriage unit clicks when I insert the battery in it. So, I am absolutely positive that this is a design or manufacturing flaw.