Abstract: A device for monitoring the environment of a battery. The device takes the form of a generally flat wafer-like substrate having openings therein for receiving the posts of the battery. The device is arranged so that it is sandwiched between the battery and its connector when the female receptacles of the connector are mated with the posts. Circuitry on the wafer contains a memory for recording information about the battery characteristics. This information can be read from the memory to provide knowledge about battery operating time, number of charge/discharge cycles, number and severity of deep-discharge cycles, total time spent in deep discharge, temperature fluctuations and G-loads applied to the battery. By taking advantage of the existing space between mated battery connectors, no additional mounting hardware or battery modifications are required.