About

To fully utilize the Seplos BMS, one has to use a closed-source, windows-only, GUI software (Battery Manager).

I didn't really like that, so I wrote a python script that can load/store settings, and also supports the main status query (code 42).

Usage

# prep env
python3 -m venv .venv
. .venv/bin/activate
pip install -r requirements.txt # only pydantic ATM

# assuming the BMS is at /dev/ttyUSB0 (check sudo "python seplos.py -h" for help)
# show current stats
sudo python seplos.py metrics

# get bms settings, and store them in XML file
sudo python seplos.py --protocol protocol/protocol.xml \
    download-settings --file settings.xml

# change settings in xml file, then upload new settings
sudo python seplos.py --protocol protocol/protocol.xml \
    upload-settings --file settings.xml

Protocol XML

At least in my case the Battery Management software also came with a folder called Agreement (protocol is probably a better name), that has detailed description of all the message fields (most notably, the settings, but also the telemetry).

The idea is that the software can support multiple different versions/variants of the more-or-less same protocol with just an XML file load (before first use).

Luckily, I can also use the same file to write a simple script to communicate with any supported BMS, as long as the protocol XML file is present.

Roadmap

• add support for more commands
  • signal (warnings etc)
  • control (charging on/off)
  • history
• add a web interface, so it can be used with an SBC
• test on other versions/variants, collect more XML files