Set up the JKBMS WiFi module, then find the connection fault

Check the module and the BMS port first

The JKBMS WiFi remote monitoring module communicates with a compatible BMS over either TTL serial or RS485. Its V1.0 specification lists a 2.4 GHz WiFi band and states that the RS485 and UART1-TTL interfaces cannot be used at the same time. Confirm the exact BMS model, port, protocol, harness, and supply arrangement before connecting or powering the module. A matching plug alone does not confirm compatibility.

Choose LAN or WAN on the side switch

The switch changes the network mode. It does not change the BMS connector, serial interface, or compatibility requirement.

First-time LAN setup from the V1.0 manual

1. Connect and power the documented hardware. Use the matching TTL or RS485 harness for the confirmed BMS port. In the initial AP state, the manual shows L2 and L3 flashing. If previously saved WiFi settings prevent this state, holding the module button for more than three seconds clears the saved WiFi configuration; it will have to be entered again.
2. Join the module hotspot. On a phone or computer, connect to JK_BMS_WIFI using the initial hotspot password 66666666 printed in the V1.0 manual. The device may say that this hotspot has no Internet; the manual says that warning is normal during setup.
3. Open the configuration page. While connected to the hotspot, open http://192.168.4.1/ or http://jkbms.local/ in a browser. Enter the target 2.4 GHz router SSID and password, and choose a local device name that is unique on that router network. Apply the configuration; the module restarts and attempts to join the router.
4. Check the LEDs and reconnect your browser. The manual identifies steady L2 with L3 off as a successful router connection. Join the same router network with your phone or computer, then open http://<your-name>.local/, replacing <your-name> with the local name you set. This is a local address, not a public Internet URL.

Do not enter or share your router password in a support request. Parameter changes in the BMS browser interface require separate authorization and should only be made for the verified battery and BMS configuration.

Read L1, L2 and L3 before resetting anything

Match the symptom to the next check

The hotspot says “No Internet” or disconnects

The no-Internet warning is expected while connected directly to the module hotspot. If the phone or computer switches away, disable automatic network switching for this setup session and reconnect. The V1.0 manual says both AP and STA modes support only one client connection at a time.

L2 is steady but L3 slowly flashes

The manual identifies this as failure to connect to the target router. Confirm the router is offering a 2.4 GHz network and recheck the entered SSID and password. If needed, hold the module button for more than three seconds to clear the saved WiFi credentials, then repeat the initial setup.

The router is connected, but the .local page will not open

Put the browser device on the same local router network as the module and use the unique local name entered during setup. The V1.0 manual requires Bonjour on Windows for .local access. It also lists duplicate local names, automatic network switching, and proxy, firewall, or VPN software as things to check when local access fails. Its suggested isolation check is another router or a phone hotspot.

L3 is steady in STA mode

The V1.0 LED table labels this as a server connection failure. It is different from the slow-flashing router failure. Record the mode, LED pattern and network state, then use the support channel if the connection does not recover; do not change BMS protection settings as a network troubleshooting step.

Source documents and help

The setup addresses, initial hotspot credentials, reset behavior, LED meanings, LAN/WAN distinction and troubleshooting checks above come from the JKBMS JIKONG WiFi Module User Manual V1.0. The 2.4 GHz radio band and TTL/RS485 interface restriction come from the WiFi Module Specification V1.0. Both are listed in the JKBMS download library.

For an unresolved case, send support the WiFi module and BMS label photos, hardware revisions, chosen LAN/WAN mode, L1/L2/L3 pattern, and phone or computer operating system. Keep router credentials and BMS authorization passwords private.