Warning: Do not change the system password on the BMS. This may result in loss of access and, in some cases, could even render the device completely inoperable.
If your BMS has been locked or disabled after a password change or a failed firmware update, follow these steps to recover:
1. Connect the BMS to the battery — only the main negative and positive terminals. Balance leads are not required.
2. Connect the communication cable to the “-” terminal of the RS485 port.
3. Set DIP Switch #1 to ON (all other switches should be OFF).
4. In the PC software, open the “Firmware Upload” tool and select the correct firmware file (e.g., version 14.19).
5. Click Force updating and enter the unlock code.
Get your unlock code by entering your serial number from the app.
6. Press and hold the BMS power button, then briefly press the reset button. Continue holding the power button until the update completes and a confirmation beep is heard.
7. The BMS will power off. Turn it back on — a beep will confirm success. All settings will be restored to factory defaults, so you may see some initial errors before connecting the balance leads.
Note: This unlock code also allows firmware downgrading — a feature not supported by the original JK method.
