You wont have any problems with that power supply, 13.8 regulated is just fine, never had any problems using mine.
Most of the dramas with the motors came about when people were just using a straight 12 Volt battery to power the mount in the field, motors got hot and burned out because not enough volts were supplied for a slew, the Lacy 18 volt converter fixed that problem, and has already been mentioned, balance is critical.
Cheers
JohnG
