I am using a P20L in my solar system. I have 1 200watt and 1 100watt panels, connected in parallel to the P20L and a 2 GC-2 batteries in series to make a 12v battery bank. The float voltage is set to 13.7 After charging for 4 hrs, i notice the P20L arrow begins to flash. Does this mean it has reached the float voltage? Are the batteries 100% charged or to do need to continue to charge them? What happens if I continue to keep charging after the arrow starts to flash? Is 13.7 the proper charge voltage setting?