The system controls the video output -- the dock can only take what it is sent and distribute it.   As above, you would be better off with a more capable system, but if you must make this one work you will need displaylink adapters to get video; it is not a power issue. It's a limitation of the feature set dictated by the sub-$500 price point of the system.  
Hey, anyone can help me with this?I have a dell inspiron 15 (3525) laptop and I want to connect two external monitors to it. What do I need to do to set up dual external monitor for my laptop?Which adapters or special cables Do I need?  
Dual screen monitor dell inspiron 15 3525