Solar controller for 33 volt panel that will bring it down to 12 volts.

[natel]

I'm new to solar and I was given a panel that is 33 volts. I'd like to use a charge controller that will bring it down to 12 volts so that I can charge three deep cycle 12 volt batteries. I'm told the panel is 13 amps at 12 volts. My question is about solar controllers. Do most solar controllers allow you to manually set the voltage to 12 or 24? Or, do most of them automatically choose the higher of the two voltages if you panel produces more than 24 volts? In any case, I would like someone to point me to a good controller that will bring this panel down to 12 volts. Thanks!

[Sunking]

You will have to use a MPPT controller and most automatically sense the battery voltage. But you have raised a RED FLAG: 3 batteries on 1 panel. You rpanel sounds like a 150 watt GTI panel and with a MPT controller can only support a 12 volt battery of 140 AH capacity.

[natel]

class c panel

Thanks for that information. I guess all I need is one large battery. And, yes it is a 150 watt bp solar panel.

Something I just learned is that this panel is a c grade panel. Does this mean that it is unsafe and can start a fire? Maybe I shouldn't use this panel at all? Or, is there a way to make it safe to use. Would it be safe on a metal roof and if it was not connected to any other panels and far from anything flammable?

You will have to use a MPPT controller and most automatically sense the battery voltage. But you have raised a RED FLAG: 3 batteries on 1 panel. You rpanel sounds like a 150 watt GTI panel and with a MPT controller can only support a 12 volt battery of 140 AH capacity.

[Sunking]

C grade cells have flaws that affect output power meaning they have lower outputs than A and B grade cells. C grade cells and panels are what is sold on Flea Bay.

[russ]

Does your C grade panel have UL listing?