That power source is not switched like it is on the CG version controller, it's on all the time and it is whatever the battery voltage is.
It depends on the exact specs of the LED in question as to what value Resistor should be used, but a 'typical' Red LED will be around 2v or so.
You'll need to use a Transistor or OC and make a switched power source on the CG2 for your LEDs. Once that's done, you'll be using anywhere from a 2.2v to 3.2v source, depending on which battery pack is used and what level of charge it has, so a 100ohm Resistor should be used on the LEDs, and they will dim some with the battery charge because that's not a regulated source like the CG controller has at that same spot.