a unit for describing the life of a battery which depends on how much current it can produce for how long. Symbol A.h. A battery with a life of 1 A.h is nominally capable of producing a current of 1 A for 1 h, or 0.5 A for 2 h, etc, before it goes flat. Since the product of current and time has the dimensions of charge, it follows that if you run a battery with 1.00 A.h capacity until it is flat, then 1 A.h or 3.6 ¥ 10 C of mobile charge will have passed through the battery. You can estimate the energy that can be delivered from a battery by taking the product of its life and its emf. For example a 2 V battery with a life of 5 A.h should be able to deliver about (2 V) x (5 A.h) which equals 2 x 5 x 60 x 60 J or 7 kJ.