500 Amp adjustable load carbon pile . Tests batteries rated as high as 1000 CCA or 160 Amp hour. Test alternators, regulators and starters . Meters are color coded for simple pass or fail diagnostics. Includes temperature compensation chart This load tester will perform variable load testing on 12 volt batteries rated as high as 1000 cold cranking amps. Use this battery tester to simulate actual cranking loads. Also tests alternator charging voltage and relative starter current draw. This features large dual meters to display the battery voltage and load current simultaneously, during the test.