What does mAh mean in batteries?
mAh is a measure of the amount of charge stored in a cell or
battery (set of cells). One (1) Ah is the equivalent of 1000mAh,
and so the statement can be made that a cell with 2000mAh of stored
charge can supply a device drawing one (1) mA for 2000 hours --
before needing replacement or recharge.
It also means 1/1000*C/s*3600s.(1 milli= 1/1000, C=Unit for
charge, s=seconds) which finally means that a battery rated 1mAh
can hold a charge equal to 3.6 coulombs of charge.