how many panels will 7 be ok? for Growatt 3000lvm-es 250v max, Newpowa 240W Mono


New Member
Feb 16, 2021
After lots of research looks like these will be a great fit for my 5th wheel roof for layout as there small I can fit them on each side easy.

I am looking at these but would use any that fit good on the roof.
under 36 inches wide is best to fit each side of the AC units, length is not so much the issue. smaller and higher power is always good on a RV.

Newpowa 240W Monocrystalline 240 Watts​

Specifications Dimension: 54.72*34.45*1.38 inches​

  • Weight: 29.12 lbs
  • Max Power Output(W): 240W
  • Voltage MPP Vmp(V): 23.32V
  • Current MPP Imp(A): 10.16A
  • Voltage Open Circuit Voc(V): 27.08V
  • Short Circuit Current Isc(A): 10.71A
for the Growatt 48v 3k unit 250v is max input & says 120v but needs at least 140v to make it work minimum even will prouse had issues with low dcv on it.

might have to just get a lower DCV 145v Growatt 3k system.
looking at the older tl lvm 3k unit it's pv input operates at 60v - 115v with 145-VOC giving me more options for wiring panels together. 3 strings of 4 panels = 93.28 VMP ,108 voc 12 panels total if lucky then 2880 watts.
any suggestions for this would be great.

I am trying to get as much wattage on roof of the 5th wheel as possible for running AC in summer and boondocking.

my concern would be low lite power output not making to 120v to run the unit. 7 x 23.32 =163.24v plenty above 140v to get the unit running.
but clouds effect the output tremendously.

as well that's only 1680 watts total I'm looking for over 2k watts I think I can get 12 or more on the roof.
I am doing a layout today with a carboard cutout to see(y). if can get 14 on roof I will run 2 strings into combiner cable so voltage stays same, or go old unit with 3 strings of 4.

if can only get 10 or 12 how do I combine the panels together to get the watts needed and still have the voltage needed for the Growatt???
while typing this I am really thinking the older LVM unit is the way to go due to lower DCV mppt input to work vs the newer lvm-es unit 120-250v dcv.

thank you everyone for the help/suggestions.
have a wonderful day.