Abstract: A state-of-charge indicator, powered by a battery to be monitored, compares a reference voltage level developed from the battery and a voltage proportional to that of the battery in a differential-type circuit employing a pair of transistors with common emitter load and each having a collector current activated annunciator; with a first annunciator being activated under conditions of battery voltage definitive of a "good" battery, both annunciators being activated for lower battery voltage indicative of a failing trend, only the second annunciator being activated for still lower battery voltage indicative of a "bad" battery, and neither annunciator being activated for still lower battery voltage indicative of a failed condition.