Parallel Support

My colleague has asked if he can:

  1. connect in parallel the following to the AC180
    2 x 200W portable folding units.

Specs for 1 unit (folding number:4)
Transformation Efficiency (EFF): >22.5%~23.4%
Voltage(Vmp):18V
Current(Imp):11.1A
Open-Circuit Voltage(Voc):23.4V
short circuit current (ISC): 13.3A

  1. is a fuse required?
  2. if so is that on both?
  3. if 22.2A will that bugger his unit or will the unit only draw 10A through its internal controller.
  4. can it be done in series for 2 portable units that fold out?

He doesn’t have a PC which is why he wanted me to ask?