12v is the most common solar panel wiring connection with batteries.
Hooking batteries to a solar panels.
However keep in mind that it s safest if you have a way to tell the positive and negative wires apart.
First of all it is essential that all batteries involved are identical and have the same state of charge.
How to connect solar panel to a battery connecting charge controller to battery connecting solar panels to charge controller connecting the ac power inverter.
Parallel connection of solar panels and batteries with automatic ups system 12v installation.
Secondly it is important to use short electrical cables of the same length and with suitable cross section for the connection of the batteries.
Connecting solar panels in series.
Generally to achieve the 12vdc to 120 230vac system both pv panels and batteries are connected in parallel.