We would expect the battery to have a serial number, whether this is stamped elsewhere on the battery or within the data taken from the QR code. Typically the two characters in a battery serial number refer to the year of manufacture from 0 to 9 and is a letter referring to the month of manufacture from A to L corresponding to January through December.

If you car was manufactured in 2015 we would not expect it to be on its original battery, as they typically are past their best by the time they are five years old.