I have 2 separate batteries that I connect together to make my power system pack. Off of each of these, I run a BEC. So I have a redundant BEC system. It's light, it's redundant and I never worry about RX battery charging. I know, lots of people will tell me that their separate RX batteries are better but I disagree. I've been running BECs for over 10 years without a single failure. To each his own.