Wa alaikum salam wa rehmat ULLAH ,
Dear Akhter , VM II requires minimum 120 volts from solar panels to start working (charging the battery) i dont know how many panels you have , but make sure their WORKING VOLTAGE (VMP or VMPP) is atleast 120 volts DC , u can get that much high DC voltage by connecting your all panels in SERIES (not in parallel) you will get very less AMPS but higher voltage . and thats the requirement of VM 2 .
connecting in series Means , plus of one panel will go into the MINUS of other panel and this chain continues .
u can ask anything about this , would like to help you in this matter .