Chad, that diode looks like an excellent choice if you decide to add it as a fail safe. You would need to bump the voltage regulator setting up a little to compensate for the drop across the diode. A fully-charged 12V battery (specific gravity of 1.265) needs 14.5-14.7 volts at the battery + terminal to maintain a good charge, but the charging current needs to be <5A when that adjustment is made. Be sure to mount it on some kind of finned aluminum heat sink in a location where it will get plenty of airflow. Even low-drop diodes develop some heat as current flows through them, and flowing tens of amps instead of the milliamp or microamp current flows that most solid state circuits use needs some serious cooling! Good luck!
Jerry
