The battery testing circuit of the present invention preferably includes a substrate, a display printed on the substrate for displaying a level of discharge of a battery, a display driver circuit coupled to the display and to the battery for receiving power from the battery to drive the display, and a battery discharge level sensing circuit coupled to the display and to the battery for sensing a discharge level of the battery and for supplying a display signal representing the sensed discharge level to the display. At least one of the circuits is printed on the substrate using processable conductive polymer materials as ink layers. Preferably, the battery discharge level sensing circuit component continuously senses the discharge level and the display continuously displays the discharge level. The display is preferably a field-responsive liquid crystal display made of either polymer liquid crystal or polymer dispersed liquid crystal material. The display may be formed of one or more layers of active liquid crystal material. The display driver circuit is preferably an oscillator that may also be printed on the substrate.