Features: Three control buttons, 4 digital tube display, 1 LEDs charge indicator. Reduce the brightness of digital display, save energy and protect eyes. Mode status: standard mode, energy-saving mode, setting mode, voltage calibration, factory setting mode. It can charge 6-60V acid batterys and lithium batterys. The default starting charge voltage is DC12V and the cut off charge voltage is 14.8V. 1% high precisions voltage divider makes the voltage measurement more accurate. The voltage accuracy and resolution are 0.1V and have calibration function.