As clearly visible in the picture it will be enough to wire the positive pole of one panel to the positive pole of the other one and then wire the negative pole of one panel to the negative pole of the other one.
How to hook up multiple solar panels together.
If you however need to get higher current you should connect your panels in parallel.
You connect solar panels in series when you want to get a higher voltage.
There will now be 12 volts coming out of this second panel.
With this being a 6 volt panel and we need 24 volts we need to increase the voltage.
If we have two solar panels with same voltage and power the connection will be very simple.
Parallel connection of two identical solar panels.
To wire two or more solar panels and batteries in parallel simply connect the positive terminal of solar panel or battery to the positive terminal of solar panel or battery and vise versa respectively as shown in the fig below.
Considering the example in the figure two 5a 12v panels wired in series produce a voltage of 24v and a current of 5a.
To do this we connect the positive side of the first panel to the negative side of the second panel.