Running a step down transformer off of an off grid 120v inverter?

it can not be programmed unless plugged in, I don't think the 9volt is what makes it keep time, the program is permanent once you set it, and then the timing is done like a global watch....  How it was explained to me...  I was going to put the kill a watt on a system in service today but the groundskeeper wasnt available to open the mechanical room, as soon as I can get in there, I am going to measure 1-when the system is idle, 2 when the system pulls in 1 valve, and 3 when it holds that valve open..  That will give me a good idea of what it will use, then the only thing I have to put the puzzle together is inverters losses...   I was really hoping to be able to do it with 2 panels and 2 100ah batteries, that is what another gentleman is using but he has a different brand clock and a 24vac inverter...  he said his works flawless and never dies...

Yes but this unit has 24vac and 7vac I spoke with matt at powerstream and he said they dont make a 7vac inverter, an option would have been finding a 24vac step down transformer/converter...  but I think the 120v is an easier route...

how I under stand it they are running 24 and 7 for the 30v the field runs on..