Relay for battery: allows Arduino to turn power to itself off when no power comes from solar panel, at night, to save power. When the sun comes up, the voltage from the solar channel will turn the Arduino back on.
Button to connect battery: When the Pi is off and the battery is connected, the relay to the battery is still off.The button allows the user to connect the battery temporarily so that the Arduino recognizes the high enough battery voltage and turns the relay on.
