Dynamic bike dynamo charging system
I'm not sure if this really counts as an answer, but I don't mind doing some maths for you:
On a 10 mile journey, assume that you're cycling at 150W output, at about 10mph, and half of that power goes into your power system (the other half is fighting against friction etc, but not sure about the percentage for that). Assume you have a 70% efficient alternator, you'll get 0.7*75=52.5W. Your journey is 10 miles, so that rounds out nicely to 52.5WH. Phone batteries are at ~3.7V, so 52.5WH=14Ah, which is equivalent to about 7 iphone 8 batteries. That will probably be ok for your phone charging needs. 

Your relaxation needs are a bit more tricky. This website says a typical motor will be around 10WH/mile at minimum, which means if you pedal 10 miles to the place, and charge 3 phones, you're only getting about 3 miles back before you have to pedal again. Of course, you could pedal at the start and use the motor later.

This isn't too bad, but none of this takes into account the fact that you're dragging a big trailer with heavy lead acid batteries behind you. I'm imagining that these calculations are sort of a best case scenario.

Also, the connections and stuff are a bit complicated. To do it properly requires control systems and power conversion. If you just want to wing it and hack it all together, you probably could, but your efficiency would probably suffer a large amount.