I have a deep cycle battery and I'm looking to charge using the MPPT method from my solar panel. Some parts of the day the voltage of the solar panel is lower than the voltage of my battery. So the buck converter wouldn't work, correct?

 

Can you rewire the panel to get twice the voltage and half the current?

 

In regard to @AaronRodgers post: That could damage the solar panel, don't you think?

What if you used a buck-boost?

 

You should use a decent MPPT controller that has built in reverse current protection ... any good unit will have it