AA

The AA battery (or double-A battery) is the North American name for a single cell cylindrical battery that measures 49.2–50.5 mm (1.94–1.99 in) in length, including the button terminal—and 13.5–14.5 mm (0.53–0.57 in) in diameter. The IEC 60086 system calls the size "R6", ANSI C18 calls it "15", and it is named "UM-3" by JIS of Japan. Several different battery technologies are available in this form factor, including: Zinc–carbon, Alkaline, Li-FeS2, Li-ion, LiFePO4, NiCd, NiMH, and NiZn.

Can you go to the grocery store and pick up some AA batteries?