Latest Firmware Update for the 4.3″ LCD Display – What’s New and How to Update

Latest Firmware Update for the 4.3″ LCD Display – What’s New and How to Update

If you’re running a JK BMS with the 4.3-inch LCD display, you’ve probably noticed that keeping the firmware up to date can make a real difference in performance, stability, and features. The latest firmware releases — particularly the V19.18 and V19.24 builds — bring several important fixes and improvements to the table.

Here’s everything you need to know about the latest firmware, what it fixes, and how to update your display.

What’s New in the Latest Firmware

The JK BMS 4.3-inch LCD display firmware has seen active development, with recent updates addressing a range of issues reported by users across various setups.

V19.24 (Latest Release)

The V19.24 firmware is currently one of the most recent official builds. Key improvements include:

  • Fixed missing minimum voltage reading — This information was previously not displaying on the LCD after V19.21, and has now been restored.

  • Fixed missing data in Victron VRM reporting — The same missing voltage information that affected the LCD also impacted VRM reporting; this has been resolved.

V19.18

The V19.18 firmware is considered a stable official release that many users have successfully adopted. It provides a solid foundation with improved reliability over earlier versions.

Earlier Fixes (V19.11+)

For users running firmware older than V19.11, updating brings critical fixes including:

  • SOC reset issues resolved — The problem where SOC would not properly reset to 100% on all batteries has been fixed.

  • Improved communication protocols — Enhanced CAN communication with inverters.

How to Update Your 4.3″ LCD Display Firmware

The update process depends on which hardware version of the display you have.

For Displays with a MicroSD Slot (Newer Versions)

Newer 4.3″ LCD displays (like the V15 and later models) can be updated directly by inserting an SD card.

Update steps:

  1. Prepare an SD card — Format it as FAT32 with a maximum size of 2GB.

  2. Copy the firmware file — Place the .bin firmware file (e.g., VTc_Project.bin) onto the SD card.

  3. Insert the SD card into the display’s card slot.

  4. Power on the BMS/display — The display should automatically detect the firmware and enter programming mode.

  5. Wait for the update to complete — Do not power off during the process.

For Displays Without a MicroSD Slot (Older Versions)

Older versions of the 4.3″ display (particularly those manufactured before 2024) may not have a built-in SD card slot. These require a different approach:

  • The display may need to be updated through the RS485 or UART connection using PC software.

  • Some users have reported that direct SD card updates are not possible on these older units.

  • Contact the manufacturer or your supplier for the specific update procedure for your hardware revision.

Common Issues and Troubleshooting

“Display won’t enter programming mode”

Some users have reported that the display does not enter programming mode even when following the instructions correctly. If this happens:

  • Double-check that your SD card is FAT32 formatted and 2GB or smaller.

  • Ensure the firmware file is the correct one for your display model.

  • Try a different SD card — some cards are not recognized by the display.

“Black screen after update”

If the display lights up but shows no information, this could indicate a firmware mismatch or a failed update. In some cases, the display may need to be re-flashed with the correct firmware version.

“Different firmware versions across multiple displays”

If you have multiple displays running different firmware versions, you may notice inconsistent features (e.g., one has multiple languages while another does not). Updating all displays to the same firmware version will standardize the feature set.

Why Update?



Issue Fixed In
Missing minimum voltage on LCD V19.24
Missing data in Victron VRM V19.24
SOC not resetting to 100% V19.11+
Faulty temperature readings (-40°C errors) V19+
Complex update fears (bricking) Resolved in V19
Parallel BMS display connection issues V19.24+

Final Thoughts

The 4.3-inch LCD display is a powerful monitoring tool for any JK BMS setup — especially for 16S LiFePO4 packs, where it can show all cell voltages simultaneously on a single screen. Keeping the firmware updated ensures you get the most reliable performance, accurate data, and the latest features.

If you’re experiencing any of the issues mentioned above, or simply want to ensure your display is running the latest software, now is a great time to check your firmware version and update if needed.

Looking for the 4.3″ LCD Display or need more information?

👉 Check out the JK BMS 4.3″ RS485 LCD Display here

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