I have built a battery level indicator and have tested with a 12V battery Would it harm my arduino board if I connect a 48V battery? - Arduino Stack Exchange
Powering Stepper Motor + L298N + Arduino w/ 12V Battery - Motors, Mechanics, Power and CNC - Arduino Forum
Trying to connect 12V DC irrigation pump using Relay and power supply - Motors, Mechanics, Power and CNC - Arduino Forum
12V Battery Backup Power Supply
12V Battery Level Monitor
Powering Arduino With a Battery (with Pictures) - Instructables
How to connect a 12V battery pack to an Arduino Mega 2560 - Quora
Arduino Nano failed after supplying by 12v - Project Guidance - Arduino Forum
One 12V battery and two DC-DC step down modules? - Project Guidance - Arduino Forum
Amazon.com: SDTC Tech 4-Pack 2/4/6/8 x AA Battery Holder with Wire Leads 3/6/9/12 Volt Battery Case Box Kit for Arduino Project Led Circuit Experiment : Electronics
12V battery meter with Arduino MEGA - Sensors - Arduino Forum