Off grid AC circuit control dependent on DC voltage

Off-grid Electric System

I want to be able to open/close AC circuits based on the voltage of my DC storage system.

My current system is 12V DC and 120V AC. My future plans will be to have a 48V DC and 120V/240V AC.

Ideas? I am new to off-grid applications but realize that control systems are absolutely necessary to design an optimal system.

My fist application is for a charging station for my cordless tool batteries. I only want them to charge when the voltage is 12.5V or higher…refrigeration is the priority, tool batteries are a lower priority.

to monitor the DC voltage you can use this board

to monitor the AC voltage you can use this

to open/close ac circuits you can use a relay board.


I am very new to this. What hardware/software do I need to program the voltages at which the relay will close and open?

You can use the above mentioned hardware with an arduino

You can find all the code sample over here


What would I need to program via Bluetooth on my iPhone?

You can use a bluz module and build an app using blynk.