yes heardlight can be powered directly from battery like GS series. but you need to have a heavier battery. Second i am not sure LEDs will work properly in headlight, but u can check that also from the person i told you about. (he is basically a heavy bike electrician) but also do these alterations. He wont disappoint you in any regard, Neither in his fee
He switched some wires clips of my bike and now it doesnt need to go to higher RPMs to generate good headlight. it gains a good beam at 2 - 3 RPM and then remains constant after that, it also prevents bulb failure. i got that alteration some six months ago. He installed a Halogen Lamp commonly known as (tube) and its working fine ever since. no change of bulb after that.
Han LEDs in back(tail) light is a good idea i am also looking for time to change tail light bulb of my CD 100 into LEDs will show you guys results when i do that.
(if you visit him give him my salam and tell him that its from the guys who got his CD 100's light altered from you, and he is very satisfied with the results. I moved to gujranwala after that and had no chance to inform him about the results. This way he will be attentative to you also