high voltage

So I'm collecting parts and kit on a new heli. It's going to be a HV setup. 6S. 100A CC ESC. Ikon. My question for the HV gurus here: Do I need to run a BEC (such as CC BEC Pro) or can I run straight off a 2S lipo pack? I believe the answer is that I can run off a dedicated Rx 2S lipo...