12v is just the familiar name for a lead acid battery system. A fully charged 12v battery is actually 13.2v and most charging systems run around 14.5v. The panel will put out more voltage when not being loaded. Just get a regulator designed for solar charging. A vendor of such chargers can help you pick the right one for your needs. I did this with a solar system for my cabin. We used a golf cart battery.
My six 12v deep cycle bank charges to 12.7 typically.