This manual charger includes a tester and is a heavy-duty model for big fleet operations and industrial use. It is ideal for repair shops that need a lot of power and it has the ability to test batteries and alternators. This charger has a very high-output engine start which assists batteries in cranking most engines under severe weather conditions. It accommodates 6 and 12-volt batteries. Its 300 amps help engines for emergency starting. The 30 amp charge charges a 6V or 12V battery in 1-2 hours. The 60 amp rapid charge works even faster. The battery load tester tests 50-amps on a 6-volt system and 100-amps on a 12-volt system.