First step was to fake the charger commands in order to verify that the communication works as expected. ✅ Next step was figuring out what other commands are supported. ✅

While most of the registers and data are known, there are still some unknown. Contributions are welcome!

Hardware

In order to simulate the charger, the following circuit is proposed:

NOTE When using fake FT232 chips, break condition is not supported. The behaviour can be emulated by using the DTR line to pull the TX line low.

List of working and non-working devices. Please add yours if not already listed.

The voltage of the USB to Serial adapter should be 3.3V

Requirements

To use this software, Python is required. Please read the python and pip documentation.

Install the required packages by running

pip install -r requirements.txt

Usage

Once the required packages are installed, run the following command. If the serial port is known, specify it using --port to speed things up.

python3 m18.py

or on Windows

python.exe m18.py

This opens an interractive shell that can be used to send different commands. Refer to the instructions provided in the shell.

Output

Most users will just want to use m.health() for a simple health report.
To see all registers, use m.read_id()
To output all registers in a format that can be copy/pasted into a spreadsheet, use m.read_id(output="raw")
To help us identify unknown registers, you can submit your diagnostics to us with m.submit_form(). This will prompt you for the 3 parts of the serial number, the type of battery (e.g. 3Ah high output), and other stuff that you can leave blank if you like

A spreadsheet template can be found below. Do NOT request access, go to File -> Make a copy or File -> Download

https://docs.google.com/spreadsheets/d/1rZZ3mtU2uwuo_uMv7O7hi5kyPA9AXUDU5CBsHKWMi-U/

Windows Users

There are 4 .bat files for Windows users that are not familiar with the command line. Double click on them to run them.

m18_idle.bat will prompt you to select a serial device, then bring the TX (J2) pin low. This is recommended before connecting to the battery to avoid increasing the counter for dumb-charges
m18_health.bat will print out a simple health report. The adapter must be conncted to the battery or you will get errors
m18_interactive.bat will put you into the interactive shell where you can call m.health(), m.read_id(), and submit your diagnostics to us with m.submit_form()
m18_clipboard.bat will fetch all diagnostic registers and copy them to the clipboard. You must right-click on this .bat file and select Edit, then change --port COM5 to whatever your port is. Once finished, you can select a cell in a spreadsheet (for example, the template provided above), and ctrl+v to copy all the registers