INPUT VOLTAGE (RECOMMENDED) is 7-12V for Arduino Mega 2560, It will be better you use a 12V DC-DC converter to connect your board to the battery.
Arduino boards will only draw the amount of currect they need to function from a supply unit.
INPUT VOLTAGE (RECOMMENDED) is 7-12V for Arduino Mega 2560, It will be better you use a 12V DC-DC converter to connect your board to the battery.
Arduino boards will only draw the amount of currect they need to function from a supply unit.