Diesel generator start

Product Discussion BLUETTI AC Series
1

Has anyone found a solution that theAC series can send a signal to start a diesel generator when the battery is low?

2

A wired-only solution would be to hook to the rs485 line of the IoT controller (pin 2 and 3) with a microcontroller and read modbus register 94 (40094) with function 03 which is a 0 to 100 char value which represent total battery percentage.
From there, you just need 2 conditions to control a relay with some hysteresis and error checking which is very important.
Keep in mind you’ll be sharing the bus with the IoT controller which likes to keep the line busy even with BT and Wi-Fi off from the LCD display settings. Quickest option will be to disconnect it and use the microcontroller as the only master.
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Another approach would be to use the public MQTT library via Bluetooth, that was kindly shared by another customer on github, I’m not using that approach so I couldn’t help you with that, but I’m sure other people that knows more than me could share their own opinion on the matter.

3

Hi, Thank you for the fast reply. Can you be a little bit more detailed on what you mean with IOT cable?
Thank you.

4

I tried this but had no function using pins 2 and 3. I switched to using pins 1 and 3 and it now works as expected. Thank you for the brief summary.

5

Hi Scott, may I ask on which port you tested this, can you send a picture of your setup?
Thank you

6

I could but I already put the unit away back in a closet I don’t wanna drag it out again

7

@Scott-Benson Right, I forgot to specify I’m referring to the AC300. Not sure and didn’t checked how the pinout could change between other AC models.
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@rolfvanhenden By opening the back panel you can see the IoT controller which is installed on the back face of the upper panel, upside down, just between the two wireless chargers.
From the controller you have a 4 pin screw terminal block:
Pin 1 (white): VIN
Pin 2 (red): RS485 A
Pin 3 (brown): RS485 B
Pin 4 (black): GND
Please note I’m still referring to the AC300, not sure what is the model of your interests.

8

Hi,

I am using a AC500 unit.