Non-USB Power for FRDM-K64F

We have the FRDM-K64F boards and want to run them off battery power. As near as we can determine, this just requires populating the J24 barrel connector and applying 5-9 volts to that connector. [It looks like Digikey parts CP1-022 and CP-012 are what we need for the board connector (J24) and the plug.] The on-board 3.3v regulator (U17) will take care of the rest, right?

The 5v regulator (J27), which is not populated normally, is not needed for battery power, correct? If so, what is it for?