AA batteries are cylindrical cells with physical dimensions (diameter x length) of 14.5 x 50.5 mm (0.57 x 1.99 inches). Its standard label is "AA", but other labels are also used, usually depending on the country, chemistry, standard, etc., including U12, HP7, Penlight, Mignon, MV1500, MN1500, MX1500, Type 316, LR6, 15A, R6, 15D, FR6, 15LF, etc. As you can see from the table, AA batteries vary...