I have inverex aerox 1.2kw inverter i have 445w * 2 =890watt of solar input 
My solar panels are Of good quality the temprature of inverter is about 40C. I get about 400watt max input on the inverter as i increase my load more than 500watt the the solar input decreases to 350watt I don’t understand the problem ,I think its the problem with software . Please help

I don't know the Inverex models well, or the lower power models. What it sounds like to me is you may have a PWM model, which effectively connect the panels directly across the battery unless that would result in too much charge current. 445 W panels are almost certainly 72 cell panels, with Vmp at about 36 V or more. Connecting them to a 28 V or even 14 V battery could explain the 45% of rated power.

As the load increases, especially past the point where the panels can keep up, the battery voltage reduces from over 28/14 V to perhaps a little over 24/12 V, which is even further from the ~36+ V Vmp, so the panel efficiency goes down even further, resulting in even less power from the panels.

If I'm right, you could improve performance by swapping to a model with an MPPT solar charge controller, or to panels better matched to your battery.

It really helps to give more details about your setup: exact inverter model, whether the panels are in series or parallel, etc.

Edited July 10, 20215 yr by Coulomb