Say you have three AA batteries each 2.5 amp hours. In the first configuration, all the batteries are in series. The voltage is 4.5V and the current capacity is 2.5 amp hours. (4.5*2.5=11.25) In the second configuration, all the batteries are in parallel. The voltage is 1.5V and the current capacity is 7.5 amp hours. (1.5*7.5=11.25) In the third configuration, two of the batteries are in parallel, with one battery behind them. The voltage is 3V and the current capacity is 5.0 amp hours. (3*5=15) So how is energy conserved here?