The answer will depend on what batteries and converter you have. If I remember correctly, Group 24s are about 70 Ah and Group 27s are about 100 Ah. If you have 2 Group 27s you will need something over 100 Ah to go from half to full charge (since the process isn't 100% efficient). If you have a 50 amp converter (I don't know what is standard on the new trailers) it will take 2 to 2-1/2 hours, or maybe more.
"You cannot reason someone out of a position they have not been reasoned into"
Al, K5TAN and Missy, N4RGO
2002 Classic 30 Slideout
2001 Safari 25 RB Twin (Gone, but not forgotten)
2013 Dodge 2500 Laramie 4x4 Megacab Cummins
WBCCI 1322, TAC FL-39, AIR 82265