I'm a newbie. Got the Phantom for Xmas, charged the batteries, and it flew fine. Batteries died down and I've tried to recharge. ( I have a BC20-4 balance charger). When I plug up to the charger I'm getting alternating red flashing lights - "Charge Status " and "1s". It's set on LiPo and 1A. I don't think I should be seeing those two lights blinking. It's not charging. What am I doing wrong?