Running a rv a.c. with relay

So I had a 2019 Mercedes sprinter and had a 12.5k btu Domestic air conditioner in the back. I have the 170 extended cargo van. Anyway I have a 500 watt solar panel with 3 aucially batteries running about 260AH. I have 2 3000w inverters. That's constant 3000 and peak 6000. But I couldn't start the AC. It would trip the safety feature in the inverter. So I got a 5000 gas generator. But that things takes up a lot of space and noisy. I got rid of the 2019 and got a 2020 note I want to do this van right the first time and I dint want a gas generator with me all the time. I got another solar panel so I'll have around 900w and I got 2 li FE po4 100ah batteries. Im about to buy a soft start but that's 300 so I rant to see if they're is anther way I could power my AC without spending another 300.I read somewhere that I might be able to control the compressor and get it to start by using this little soft start with a relay. Any ideas how.

What is the A/C compressor's starting and running current? Surely you did not try to parallel the output of 2 inverters. Single phase motors can take 7 to 10 times the running current to start.

First check what sort of compressor motor your AC has in it.
Some are now inverter types, which means they are already electronically speed controlled.

Check with the AC manufacturer and ask if the AC is suitable to run from a power inverter supply.
I gather most aren't due to their high starting loads and non mains supply type characteristics of a power inverter.

What is the kW rating of your AC?

Tom... :slight_smile:

And are the inverters you are using full sine wave inverters of do they output a stepped square wave?


The reason I asked is because every step up in voltage causes the stall current to be drawn by the motor. A sine wave spreads that current over a longer period of time, so it goes from max in the beginning of a cycle to lower and lower as the voltage increases for that part of a cycle.

Scroll compressors don't have the same high current spike as piston compressors.