We recommended a factor of safety of at least 1 25 meaning you would multiply the current from your panels by 1 25 and then compare that to the 30 amps.
How to match solar panel with battery.
Solar panel output is measured in watts.
Match the solar panel to the battery.
Then the moment the cloud dims in which the solar panel can t produce enough voltage the relay will change the inverter s source which is from solar panel to battery.
The vmpp of your array or single panel should be 1 15 to 1 3 times the nominal battery voltage.
Add a solar panel to keep your backup battery topped up step 1.
All panels at the low end of wattage output.
The inverter will get the source from the solar panel while the battery is being charged.
Portability and cost are the two major factors.