esphome-wattcycle-ble

WattCycle BLE BMS implementation for ESPHome.
Tested with: ESPHome 2026.4.3, ESP32 WT32-ETH01, WattCycle 12V 100Ah Deep Cycle Trolling Motor Battery.
Should work with all WattCycle Bluetooth series batteries.

Features

• Supports multiple batteries
• battery_voltage Total battery voltage, in V
• battery_current Battery current, in A
• battery_power Calculated power, in W
• soc State of charge, in %
• remaining_ah Remaining capacity, in Ah
• total_ah Total/full charge capacity, in Ah
• design_ah Nominal design capacity, in Ah
• cycles Number of battery cycles
• mos_temperature MOS/BMS temperature
• pcb_temperature PCB/BMS temperature
• cell_spread_mv Max-min difference between cells, in mV
• cells_v List of individual cell voltages, in V
• cell_temps List of cell/probe temperatures, in °C
• model_or_fw Model or firmware reported by the BMS
• manufacturer Manufacturer field, if provided by the BMS
• serial Serial or identification field of the BMS

How to use

1. Enable external component

external_components:
  - source: github://frabnet/esphome-wattcycle-ble

2. Setup BLE connection

# BLE tracker
esp32_ble_tracker:

# BLE client
ble_client:
  - mac_address: "C0:D6:XX:XX:XX:XX"
    id: wattcycle_ble_client_batt1

# Optional: switch to enable/disable connection
switch:
  - platform: ble_client
    ble_client_id: wattcycle_ble_client_batt1
    name: "BATT1 BLE Connection"
    restore_mode: RESTORE_DEFAULT_ON

3. Expose desired entities

wattcycle_ble:
  - ble_client_id: wattcycle_ble_client_batt1
    update_interval: 10s
    battery_voltage:
      name: "BATT1 Voltage"
    battery_current:
      name: "BATT1 Current"
    battery_power:
      name: "BATT1 Power"

Please refer to demo.yaml to see all possible configurations.