How do you do this? I can get a solar panel with negative and positve lead wires... I'm new to electronics, wishing to learn.
Thnx.
/ / /
/ Solar panel +12V usually
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+__-
/''''|____| 12 v battery
_/
|MEGA| arduino
Umm like this 
jokes aside, you have your solarpanel charging a battery and the arduino connected to the battery, Arduino usually can take 12V (if not using the 3V version) but it will run hotter than one using 6-8 volt. It is preferable to run the Arduino on more than 5V, but not very much over. The solarpanel usually has some Driver-thingy to control the charging of the battery. + of solar panel to + of battery and - of solarpanel to - of battery, might be wise to have some current limiter between the battery and Arduino cause it draws current in the mA range and the battery can give current in tens of Ampers, Its a nobrainer