Project Feasibility Controlling Inverters through RJ9 Cable in my Van

Hi all and thanks for your time! I am new to Arduino but a computer nerd in my normal life.

I have a battery management system that I would like to be able to turn off/on my inverter in my Van. The battery management system is designed to switch an inverter that has a single pole single throw ON/OFF switch. My inverter has a momentary switch both on the device and on a remote that plugs in through an RJ9 cable. This remote shows ON /OFF state by switching on a LED. It seems to me that one could use an Arduino board to hijack the signal from the battery management system and then check the LED state and then send the on/off signal to the inverter. Is this doable? Can someone point me to some resources that might help? There are many other folks building systems similar to mine and I would love tofigure this out and give back to the community.

Thanks again!

Make some kind of drawing to give us some overwiew and attach it. Voltage levels are valuable.

Thanks Railroader! The battery management system is in the mail and I a have not taken the controller for my inverter apart but can do that and report back.

Here is the documentation for the BMS

That should be doable! I don't completely understand the function of both switches, but switches can be replaced by relays. (A relay is an electrically-controlled, electrically-isolated switch.)

You can't directly drive a relay coil with the Arduino but there are relay boards with built-in driver circuits so you don't have to build your own circuit.

The LED should have a resistor in series and it's best to tap-in before the resistor so you get the full 5V (or 12V or whatever it is). If it's 12V you can use an [u]over-voltage protection circuit[/u] on an Arduino input pin.

...I did something similar a long time ago - Putting a relay in parallel with an existing momentary switch while monitoring the state of an LED. (It didn't have a microprocessor. It used a flip-flop but I don't remember the exact circuit and I'm not sure if it would work in your application.)

Thanks DVDdoug! I am taking the remote apart to test the signals it is sending.

Here is the controller.

The designer of the BMS stated the this regarding the switching signal "a toggle switch is needed as that way inverter is ON when close circuit and OFF when open circuit and that is the type of signal SBMS0 provides"

The button completes the circuit and need to be held for around 500 milliseconds.

Again this is my first dive into Arduino but this seems fairly doable I would think.