A condition indicator assembly (tester) for determining the condition of a main cell, e.g. a battery, is disclosed. The condition indicator assembly may comprise an electrochemical indicator cell connected in series to an auxiliary cell. The indicator cell and auxiliary cell each have an anode, cathode and electromotive force (e.m.f.) of its own. The condition indicator assembly may be permanently connected in parallel to the terminals of a main cell being tested. The condition indicator assembly is thin enough that it may be integrated into a label for the main cell. As the main cell discharges, the indicator cell anode clears proportionally to the discharge of one of the electrodes of the main cell to provide a continuous visually discernible indication of the state of charge of the main cell. 00000