🛠️ Deep Dive: Modding JK BMS with Custom ESPHome Firmware

The JK BMS communicates over Bluetooth Low Energy using service 0000ffe0-0000-1000-8000-00805f9b34fb. Our custom ESP32 firmware connects as a BLE GATT client and parses the incoming notify frames. Below is the production ESPHome snippet executing the Bluetooth-to-Wi-Fi gateway:

esp32_ble_tracker:

ble_client:
  - mac_address: C8:47:8C:xx:xx:xx
    id: jk_bms_ble

jk_bms_ble:
  ble_client_id: jk_bms_ble
  update_interval: 15s

sensor:
  - platform: jk_bms_ble
    total_voltage:
      name: "Battery Total Voltage"
      id: pack_voltage
    current:
      name: "Battery Current"
      id: pack_current
    battery_level:
      name: "State of Charge (SOC)"
      id: pack_soc
    delta_cell_voltage:
      name: "Cell Delta V"
      id: cell_delta_v

# Automated Delta-V Cool-Off & 15-Second Cloud Telemetry Push
interval:
  - interval: 15s
    then:
      - http_request.post:
          url: "https://buyindore.com/monitoring/api.php"
          headers:
            Content-Type: "application/json"
            X-Auth-Token: !secret telemetry_api_key
          json: |-
            root["voltage"] = id(pack_voltage).state;
            root["current"] = id(pack_current).state;
            root["soc"] = id(pack_soc).state;
            root["delta_v"] = id(cell_delta_v).state;