How to Update JKBMS PB V19 BMS Firmware: Step-by-Step Guide

This illustrated tutorial demonstrates upgrading a JKBMS PB V19 BMS from V19.31 to V19.34 using JK-BMS-MONITOR 3.4.0. It also introduces the PC interface and its main functions. Battery parameter values shown in screenshots are outside the scope of this guide and should not be copied.

Scope of this tutorial: V19.31 to V19.34 is only the example shown in the screenshots. PB Series BMS boards with V19 hardware can use the same method to upgrade from any earlier V19 firmware release to the latest compatible V19 release. The installed version does not have to be V19.31, and the target version is not limited to V19.34. Always select the firmware confirmed for your exact PB model and V19 hardware revision. This does not permit upgrading V15 hardware with V19 firmware.

For PB V15 users: the PC connection and firmware upgrade workflow are similar, so you can follow the same operating steps using firmware confirmed for your exact V15 board. The latest V15 version confirmed for this guide is V15.41. Use V15 firmware on V15 hardware only. Never use the V19 firmware shown in this tutorial on a V15 board, or V15 firmware on a V19 board.

Download the PC software, manual and firmware

Download JKBMS PC Monitor for Windows

Download the PC Monitor User Manual, Version 2.0

Firmware is available in the JKBMS Download Center. Expand Firmware and choose the package confirmed for your exact model and hardware revision.

• Download JKBMS-PBXX-V19.34 — target version used in this tutorial
• Download JKBMS-PBXX-V19.31 — starting version shown in this tutorial
• Download JKBMS-PBXX-V19.27 — other available version

For this tutorial, extract the V19.34 archive and select the file confirmed for your board. For later updates, select the latest compatible V19 package for your exact model. A higher version number alone does not establish compatibility. Never install firmware intended for another hardware revision.

Before updating: prepare a reliable PC connection

Back up your existing configuration. Arrange a safe maintenance period with a qualified installer, following the installation's shutdown and isolation procedures while maintaining the BMS supply required for flashing. Keep PC and BMS power stable, prevent the PC from sleeping, and do not disconnect the communication cable during updating.

APP address, UART1 protocol and DIP switches

The device address range is 0–15, providing 16 distinct addresses for up to 16 devices in parallel. Assign a different address to each device in a parallel system and keep its APP address consistent with its DIP-switch configuration.

The actual single-device connection demonstrated in this tutorial uses:

• DIP switches: 00000, with all five switches OFF.
• APP Device Address: 0.
• UART1 Protocol No.: 001-JKBMS-RS485 Modbus V1.0.

These are the confirmed settings for the illustrated installation. The Version 2.0 PC manual describes a different address arrangement; use the actual interface-board markings and the confirmed setup described here rather than combining the two arrangements. Record any previous protocol setting for restoring the installation's required configuration afterward.

Connect a USB-to-RS485 adapter to RS485-1 on the PB interface board, then connect USB to the computer. Verify the RJ45 pinout before wiring. Do not use the B/BD USB-to-TTL/GPS-port method or the PB TTL display connector. P-LINK is not suitable for PB.

Buy the JKBMS USB-RS485-RJ45 converter cable (JK-RS485-USB-2M).

CH340 driver and COM port selection in Windows

If the computer does not have the required CH340 driver installed, download it from the Download Center or use this direct link: Download CH340 Driver for Windows (CH341SER.EXE). Install the driver required for your adapter, then check the adapter in Windows Device Manager.

Expand Ports (COM & LPT) and locate USB-SERIAL CH340 (COMx). The screenshot below shows COM7 as an example only. Windows assigns the COM port, so it can differ between computers or connections. Always select the actual COM number shown for your adapter, not a fixed number copied from this guide.

In the PC software's lower-right connection area, select device address 0 for this demonstration and the actual COM port identified in Device Manager, then click Connect. Verify that live readings appear before attempting an update.

PC interface and function overview

Realtime

The Realtime page provides an overview of battery status, charge/discharge state, balancing status and warnings. This section introduces the display only; it does not explain or recommend battery parameter values.

Settings

The Settings page provides configuration tools, including Export, Import and Send Batch in the illustrated toolbar. Verify PWD authorizes changes. Battery parameter setup is not covered here; do not copy the displayed values or import another battery's configuration.

Control

The Control page provides operating controls such as Charge, Discharge and Balance, plus model-dependent options. Changes require authorization. Do not change operating controls, emergency functions or sensor settings just to follow this firmware guide.

Verify or modify the settings password

After authorization, the screenshots show Modify PWD. The password-change dialog contains Old password, New password and Confirm password fields. Changing the password is optional, not a required firmware-update step. Use your current authorized password and keep a secure record if you change it.

Logging

The Logging page displays recorded events. Update refreshes the BMS logs; Export saves logs for review. Relevant logs can help support investigate a problem. Detail Logs is a separate navigation tab and is not illustrated here.

About: confirm the starting version V19.31

Use About to identify the model, hardware and installed software. Before updating, the example shows JK-PB2A16S10P, hardware V19A, software V19.31. This is one example board, not proof that one firmware file fits every PB model.

Firmware upgrade: V19.31 to V19.34 example

Step 1: open the update window

With the intended BMS connected, click the firmware icon in the upper-right corner highlighted below. The illustrated software opens Upload Firmware.

Step 2: select the matching V19.34 firmware

Use the file-selection button beside Firmware to choose the extracted file confirmed for your board. Verify the displayed Device ID and Version. This tutorial selects JK-PB2A16S10P, V19.34. Do not use it for another model simply because it is in the V19 family.

Step 3: start the normal update

Click Start Updating, not Force Updating, for a normal upgrade. Let the progress bar advance without interrupting power, the PC or the USB/RS485 connection. The 17% shown is an intermediate stage, not completion.

Step 4: confirm success

Wait for the completion indication. The example displays Upload firmware successfully! Click OK to acknowledge it. Follow any additional instructions supplied with the confirmed firmware package; do not guess a restart sequence.

Step 5: confirm the installed version V19.34

Read About again. Software Ver changes from V19.31 to V19.34, while Hardware Ver remains V19A.

After updating

Check your saved configuration before returning the system to service. Recheck CAN and RS485 communication settings, which may reset during updating. Restore the confirmed installation settings where required, including any protocol changed for the PC connection. Verify inverter communication and complete the system checks before resuming charging or discharging. Detailed battery parameter adjustment is outside this guide.

Force Updating: contact support first

The manual's forced-upgrade procedure requires an upgrade authorization code supplied by the BMS manufacturer. Its documented sequence is to select the confirmed firmware, choose forced upgrade, enter the manufacturer-provided code, confirm, then press the system's RST reset button and wait.

This is not the normal update route. Contact support first to confirm the recovery file, authorization code and suitability for your board. Do not guess codes or repeatedly try different firmware. Recovery is not guaranteed for every failed flash.

Shop PB V19 BMS by model

Choose the required model using its product specifications. These purchase links do not mean the example firmware file is interchangeable across models.

• JK-PB1A16S10P V19 — 100A, 1A active balance
• JK-PB1A16S15P V19 — 150A, 1A active balance
• JK-PB2A16S15P V19 — 150A, 2A active balance
• JK-PB2A16S20P V19 — 200A, 2A active balance
• JK-PB2A16S30P V19 — 300A, 2A active balance

Troubleshooting and support

No PC connection: check wiring, adapter driver, actual COM port, matching DIP/APP/PC device addresses, and UART1 protocol 001-JKBMS-RS485 Modbus V1.0. Do not start flashing without working communication.

BMS starts but inverter communication is missing: compare CAN/RS485 settings with your backup and restore the confirmed configuration.

Update fails or the BMS does not start: stop further attempts and contact support before trying forced updating.

Provide your order number, complete PB model, hardware/software versions, selected filename, error screenshots, relevant logs and connection photos.

Support: https://jkbms-ess.com/pages/support
Email: service@jkbms-ess.com
WhatsApp: https://wa.me/18189383175

Reference: Energy Storage System Upper Computer User Manual, Version 2.0, for general PC software functions; actual address and protocol settings follow the illustrated installation confirmed by JKBMS-ESS.