The Gys 024199 digital battery tester with printer, suitable for 12v wet and gel batteries. Tests batteries 30-220Ah with a minimum voltage of 6v. Unit will also test the charging and starting system of a 12v vehicle. Advanced dynamic resistance measurement technology minimises battery discharge and displays an accurate result which is unaffected by: the surface charge, parasitic load (lights, various indicators, etc), contact defaults (worn out terminals/ lugs, unfastened lugs, etc). HIGHLY ACCURATE Automatic compensation for external temperature. Advanced dynamic resistance measurement technology minimises battery discharge and displays an accurate result which is unaffected by : the surface charge parasitic load (lights, various indicators, etc) contact defaults (worn out terminals/ lugs, unfastened lugs, etc) PRACTICAL Large LCD backlit display Multilingual interface Protected against polarity reversal ABS case (acid resistant) Power supply : no internal battery, will power up using the vehicle battery INSTANT ANALYSIS Battery voltage (6 V to 20 V) Available starting power Charge state and battery health (%) FEATURES Battery 12 V : test of the voltage level and state of charge. Starter 12 V : test the start voltage. Alternator 12 V : tests the no load voltage and charging voltage as well as current undulation during the charge. Special feature to test the internal resistance of the battery. Print-out of the results using integrated thermal printer (no ink required).