Question: what is a size 10 battery?
Answer: The sizes from smallest to largest are: 5, 10, 312, 13 and 675. Size 5 hearing aid batteries are rarely used. The four most common hearing aid battery sizes are all smaller than the diameter of a dime: Size 10 - 5.8 mm wide by 3.6 mm high. Size 312 - 7.9 mm wide by 3.6 mm high.