Abstract: A battery charge/discharge monitor circuit (10) is operable to be disposed in a battery pack (12) which can be connected to a battery (13). The monitor circuit (10) is operable to be connected to an external CPU (24) or similar system through a single wire communication port (22) for transferring information back and forth. There is also provided an external signal on a line (30) for indicating charge or discharge activity in the monitor circuit (10). The monitor circuit (10) is operable to collect information regarding the amount of charge input to the battery and the length of time that the charge is input to the battery and also the amount of charge that is removed from the battery and the length of time that the charge is removed. This information is stored in a memory block (62) for later access by the external CPU (24). This system also provides offset information to provide some type of compensation for non-linearities of the part.