read external 6V power source via 5V driven arduino - Motors, Mechanics, Power and CNC - Arduino Forum
Amazon.com: SDTC Tech 4-Pack 1/2/3/4 x AA Battery Holder with Wire Leads 1.5/3/4.5/6 Volt Battery Case Box Kit for Arduino Project Led Circuit Experiment : Electronics
Battery controller Motor and power supply - MIT App Inventor Help - MIT App Inventor Community
Connect a 6V battery to the VIN port - Project Guidance - Arduino Forum