Both of the batteries that came with my CS will not charge anymore.  When I place them in the cradle, the LED lights flash quickly and then just stay in the solid yellow.  To my understanding this means they are ready to charge.  But they don't.  They charged fine a few days ago.  Am I missing something?

Please check to see if this a charger concern or a battery concern. You can test other batteries to see if the charger is working. If the issue is ongoing, send me a personal message and we will see about a solution for you.

Question on the DJI crystalsky charging hub. I see two USB ports and the other for the charging cord. The large USB is for charging other electronics. What is the small USB for?