Abstract: A built-in battery integrated circuit (50) in the form of a flexible circuit board (70) of a consumer battery (10) senses a voltaic cell electrode (32″, 34″) voltage, and when the voltage is indicative of a low state of charge, activates an indicating system (11), alerting a user to the impending battery failure. In addition, a tester actuator button (15) is placed exteriorly on the battery container (12) to manually activate the indicating system (11) to verify that the battery has not become so low of charge as to prevent the indicating system from functioning. Advantageously, the tester actuator button (15) may further enable the built-in battery integrated circuit, thus having all internal electronics unpowered until a user decides to use the battery (10). The indicating system (11) includes an analog indicator such as a bargraph and/or a pulse indicator (64) such as an LED or LCD.