It really depends on how much current the lights draw. If they're just some 10mm LEDs or something, then you might be able to get away with powering them from the vesc, but if they draw more power, then the only options you have are either power it from the main battery, or add a little extra battery just to run the lights.
Those look like commercial lights, so they should have a rating on them, e.g. 12v 300ma or 12v 5w. If not, you can use a multimeter to check the voltage and current.