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Copy of Firmware Updates

Firmware Update Guide - Pace BMS & Seplos V4

Firmware Update Guide

  • Pace BMS (PBMS)
  • Seplos V4 BMS

Updating Pace BMS (PBMS)

Warning: Please read carefully. Incorrect updates may brick the BMS.

  1. Open the downloaded firmware file.
  2. Extract the contents of the firmware file.
  3. Open the BMS Upgrade V1.03 Program. Ensure PBMS tools is not running during this process.
  4. Connect the RS232 cable to the battery and USB port on your computer.
  5. Select the correct serial port. You can check this by going to Device Manager > Ports (COM & LPT).
  6. Enter the password: 541800.
  7. Click "Browse" and locate the firmware .bin file.
  8. Click "Upgrade" to begin the process.
  9. Confirm when prompted.
  10. The program will show progress like this:
    Pace BMS Upgrade Progress Screenshot
  11. Once complete, you should see this message:
    Pace BMS Upgrade Success Screenshot
  12. After successful flashing, unplug the battery and reconnect it to restart.
  13. Verify the firmware version in the PBMS Tools software under the "About" section.

Tip: Keep a copy of the previous firmware version in case you ever need to roll back.

Updating Seplos V4 BMS

Warning: Flashing incorrect firmware or interrupting the process may permanently damage the BMS.

  1. Ensure the battery is powered and at a stable voltage. Disconnect any loads and chargers during the update.
  2. Install necessary USB-to-Serial adapter drivers (e.g., FTDI or CP2102) on your Windows PC.
  3. Connect your PC to the BMS communication port:
    • RS485: Use a USB-to-RS485 adapter (connect A and B lines).
    • UART: Use a USB-to-UART adapter (TX, RX, GND lines).
  4. Open the Seplos BMS Update Tool (usually included with the firmware package from Seplos).
  5. Select the correct COM port in the Update Tool (confirm in Device Manager).
  6. Set the baud rate to 115200bps (unless specified otherwise in the release notes).
  7. Click "Browse" or "Load" to select the correct firmware .bin file for your Seplos V4 BMS.
  8. If required, put the BMS into Bootloader Mode:
    • Power off the BMS.
    • Short the Boot pins (refer to the Seplos V4 hardware manual for pin location).
    • Power the BMS back on while keeping the pins shorted, then release after a few seconds.
    • Note: Some Seplos V4 units enter bootloader mode automatically when commanded by the update tool.
  9. Click "Start" or "Program" to begin firmware upload.
  10. Wait for a success message such as "Download OK" or "Programming Successful".
  11. After flashing, power cycle the battery.
  12. After reboot, use the Seplos Monitor Tool to confirm firmware version and check for correct operation (cell voltages, SOC, MOSFET states, etc).

Important: Only use Seplos-approved firmware for your exact BMS model and hardware revision.