DIYBMS Announcements

Hello, I’ll use this thread to provide announcements of new features that are released or currently in progress.


A frequently asked feature for diyBMS is to add in ranges for the monitoring rules, this helps to avoid relays and devices from “clattering” on and off near the rules setpoint.

Today I’ve introduced this feature, which should be considered experimental. The code is below on GITHUB. You can download and program this to the controller (no need to reprogram modules) using PlatformIO and VSCode.

Source code: []

Please report any issues you have on GITHUB - the issue page is here [Add hysteresis to relay rules · Issue #34 · stuartpittaway/diyBMSv4Code · GitHub]

The rules have now been moved to their own page, and a new “reset” value is now available.

The timer feature has also been changed, you now get 2 daily timers with a start and end time for each.

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Just a quick update on progress that I’m making behind the scenes. The below board is a prototype design for a new controller module using the ESP32.

The board has hardware for:

  1. Two mechanical relays (5A, 60V)
  2. One 0.5A, 60V SSR relay (on board)
  3. An ATTINY/Arduino ISP programming header (so the controller can program the modules without needing PlatformIO or a computer/USBASP interface)
  4. RS485
  6. Four additional I/O pins
  7. Two connectors for connecting the existing modules to
  8. A colour TFT screen supporting SD CARD and Touch - although this is optional as most people won’t need it.
  9. An RGB LED for status

The board is physically larger 122mm x 87mm but is designed to fit inside a DIN rail enclosure, like this one.


There are no release dates or files available for this at the moment, and no code has been written to support the new features - but I’ve ordered some prototype PCBs to begin all that.