B&K Precision 601 Battery Capacity Analyzer, 20V Max Input Voltage, 6V and 12V Testable Voltage Works with 6V and 12V lead acid batteries Settable Ah from 1 to 100 in 1Ah steps (works best on batteries from 5 to 99Ah) Powered by the battery being tested It tests lead acid batteries and displays the battery's stored charge capacity as a percentage 1 Year warranty