4221 watt hours equals 15.2 megajoules.
Convert 4221 watt hours into joules, kilojoules, calories, newton meters, foot pounds, kilowatt hours, megawatt hours, mega electrons, etc...
Convert 16 megajoules into joules, kilojoules, calories, newton meters, foot pounds, kilowatt hours, megawatt hours, mega electrons, etc...