OptiMate TEST Cranking & AlternatorOptiMate TEST – Cranking & Alternator: 12V tester for battery state of charge, cranking performance and vehicle charging system.The ultimate pocket tester for on-vehicle battery performance & alternator voltage testing with either 12V lead-acid or 12.8V LiFePO4 starter battery. Easy troubleshooting from cranking to charging!For vehicles fitted with 12V AGM, GEL and STD lead-acid or 12.8V LFP / LiFePO4 starter battery.As easy as 1-2-3, connect to battery, check state of charge, start engine tester displays cranking voltage and vehicle charge voltage simultaneously, 15 sec is all you need!Display cranking volts down to 6V and charge voltage range up to 15V. Check weak battery or overcharging!Easy to use! Connect with the included clips to the battery or connect to an installed SAE battery lead.