They're entirely different battery sizes.
AA = 14500
18650 = 18650 (so 4mm thicker, and 15mm longer)
Also, 18650 generally implies lithium-ion 3.6V chemistry or LiFePo4 3.0/3.2V chemistry. AA doesn't really imply a chemistry at all (though generally it would be nimh, alkaline, etc - really anything producing 1.2 or 1.5V)
I've only seen 18650 batteries in pictures and they looked pretty much the same in the pictures so I didn't know the difference. but thanks for answering my question!:thanks:
I've only seen 18650 batteries in pictures and they looked pretty much the same in the pictures so I didn't know the difference. but thanks for answering my question!:thanks:
18650 < most common Li-Ion cell size
14500 < AA-sized Li-Ion cell
10440 < AAA-sized Li-Ion cell
RHD implied this, but it wasn't explicitly stated in this thread, so here you go:
XXYYZ - Li-Ion cell naming convention
-XX = diameter of the cell in mm
-YY = length of the cell in mm
-Z = almost always 0, which designates a cylindrical cell. Dunno what other values for Z might show up.
Often the Z value is treated as a third digit of the Y designation. Why fractional millimeters are necessary, I have no idea. Look at 15266 batteries (CR2)
The first two are width in mm, the rest are length in mm with one decimal place. The one decimal place helps for naming button cells.
Ex.
Cr2032= 20mm wide, 3.2mm tall