Megaboost Pro Series 4000 Charger And Maintainer The Megaboost Pro Series 4000 has the ability to charge and maintain both 6v and 12v lead acid batteries. Features include battery testing, float charging, recovery mode, overcharge and short circuit protection. Features Checks for proper battery polarity connection and for internal battery damage Automatically detects 6v or 12v battery Switches from charge mode to maintenance mode when a battery is fully charged Easy to read LED lights indicate power on, 6v or 12v mode, 2 amp or 4 amp charge rate, and battery charge status 2 amp charge rate for 6v battery Select between 2 amp or 4 amp charge rate for 12v battery Overcharge and short circuit protection Includes quick disconnect SAE battery terminal and alligator clip leads Safe for use on all 12v Lead Acid type batteries including, conventional flooded (wet), factory activated maintenance free (Mf/Fa), absorbed glass mat maintenance free (Agm), and gel (Gel Electrolyte) type batteries