Your battery wiring is correct.
The battery post labeled "Solenoid" is also called Pack Positive.
The battery post labeled "Controller B-" is also called Pack negative.
When the 48v->12v Converter is installed up front, the 10ga blue wire carries the +48v to the Converter input.
This thread below has more information and wiring diagrams about it:
http://www.buggiesgonewild.com/elect...ml#post1231905