SY6970 Battery Management IC

The sy6970 component allows you to use the SY6970 battery management and charging ICs SY6970 Datasheet with ESPHome.

The SY6970 is a highly integrated battery charger and system power path management device for single-cell lithium-ion and lithium-polymer batteries. It features a wide input voltage range, programmable charge current and voltage, and comprehensive safety features.

This component is found in the LilyGo T-Display S3 Pro.

The I²C Bus is required in your configuration for this sensor to work.

This implementation was inspired by lewisxhe/XPowersLib Arduino Library.

Component/Hub

The SY6970 component must be defined in your configuration to set up the device. All other platforms below refer to this component.

# Example configuration entry
i2c:
  - id: bus_a
    sda: GPIO5
    scl: GPIO6

sy6970:
  id: pmu
  address: 0x6A
  enable_status_led: true
  input_current_limit: 1000
  charge_voltage: 4200
  charge_current: 500
  precharge_current: 128
  charge_enabled: true
  enable_adc: true
  update_interval: 1s

Configuration variables

• id (Optional, ID): Manually specify the ID used for code generation.
• address (Optional, int): The I²C address of the device. Defaults to 0x6A.
• enable_status_led (Optional, boolean): Enable or disable the status LED on the IC. Defaults to true.
• input_current_limit (Optional, int): Input current in milliamps. Accepts values between 100 and 3200. Defaults to 500.
• charge_voltage (Optional, int): Charge voltage in millivolts. Accepts values between 3840 and 4608. Defaults to 4208.
• charge_current (Optional, int): Charge current in milliamps. Accepts values between 0 and 5056. Defaults to 2048.
• precharge_current (Optional, int): Pre-charge current in milliamps. Accepts values between 64 and 1024. Defaults to 128.
• charge_enabled (Optional, boolean): Enable or disable charging. Defaults to true.
• enable_adc (Optional, boolean): Enable or disable the ADC. Defaults to true.
• All other options from I²C Device.
• update_interval (Optional, Time): The interval to check the sensor. Defaults to 5s.

Sensor

The sy6970 sensor platform exposes voltage and current measurements from the SY6970 IC.

# Example configuration entry
sensor:
  - platform: sy6970
    sy6970_id: pmu
    vbus_voltage:
      name: "VBUS Voltage"
    battery_voltage:
      name: "Battery Voltage"
    system_voltage:
      name: "System Voltage"
    charge_current:
      name: "Charge Current"
    precharge_current:
      name: "Precharge Current"

Sensor Configuration variables

• sy6970_id (Optional, ID): The ID of the SY6970 component. Defaults to the only SY6970 component in your configuration.
• vbus_voltage (Optional): The voltage on the VBUS (USB) input in volts.
  • All options from Sensor.
• battery_voltage (Optional): The battery voltage in volts.
  • All options from Sensor.
• system_voltage (Optional): The system voltage in volts.
  • All options from Sensor.
• charge_current (Optional): The charging current in milliamps.
  • All options from Sensor.
• precharge_current (Optional): The precharge current in milliamps.
  • All options from Sensor.
• All other options from Sensor.

Binary Sensor

The sy6970 binary sensor platform exposes charging state information from the SY6970 IC.

# Example configuration entry
binary_sensor:
  - platform: sy6970
    sy6970_id: pmu
    vbus_connected:
      name: "VBUS Connected"
    charging:
      name: "Battery Charging"
    charge_done:
      name: "Charge Done"

Binary Sensor Configuration variables

• sy6970_id (Optional, ID): The ID of the SY6970 component. Defaults to the only SY6970 component in your configuration.
• vbus_connected (Optional): Indicates whether VBUS (USB power) is connected.
  • All options from Binary Sensor.
• charging (Optional): Indicates whether the battery is currently charging.
  • All options from Binary Sensor.
• charge_done (Optional): Indicates whether charging is complete.
  • All options from Binary Sensor.
• All other options from Binary Sensor.

Text Sensor

The sy6970 text sensor platform exposes status information from the SY6970 IC as text.

# Example configuration entry
text_sensor:
  - platform: sy6970
    sy6970_id: pmu
    bus_status:
      name: "Power Source Type"
    charge_status:
      name: "Charging Status"
    ntc_status:
      name: "Battery Temperature"

Text Sensor Configuration variables

• sy6970_id (Optional, ID): The ID of the SY6970 component. Defaults to the only SY6970 component in your configuration.
• bus_status (Optional): The type of power source connected. Possible values are:
  • No Input - No power source connected
  • USB SDP - USB Standard Downstream Port
  • USB CDP - USB Charging Downstream Port
  • USB DCP - USB Dedicated Charging Port
  • HVDCP - High Voltage Dedicated Charging Port
  • Adapter - Dedicated adapter
  • Non-Standard Adapter - Non-standard adapter
  • OTG - OTG mode
  • All options from Text Sensor.
• charge_status (Optional): The current charging status. Possible values are:
  • Not Charging - Battery is not charging
  • Pre-charge - Battery is in pre-charge phase
  • Fast Charge - Battery is in fast charge phase
  • Charge Done - Charging is complete
  • All options from Text Sensor.
• ntc_status (Optional): The battery temperature status based on NTC thermistor. Possible values are:
  • Normal - Temperature is in normal range
  • Warm - Battery is warm
  • Cool - Battery is cool
  • Cold - Battery is cold
  • Hot - Battery is hot
  • All options from Text Sensor.
• All other options from Text Sensor.

Complete Example

Below is a complete example configuration for the LilyGo T-Display S3 Pro v1:

# Complete configuration example for LilyGo T-Display S3 Pro
i2c:
  - id: bus_a
    scan: true
    sda: GPIO5
    scl: GPIO6

sy6970:
  id: pmu
  address: 0x6A
  update_interval: 1s
  enable_status_led: true
  input_current_limit: 1000
  charge_voltage: 4200
  charge_current: 500
  precharge_current: 128
  charge_enabled: true
  enable_adc: true

sensor:
  - platform: sy6970
    sy6970_id: pmu
    vbus_voltage:
      name: "VBUS Voltage"
    battery_voltage:
      name: "Battery Voltage"
    system_voltage:
      name: "System Voltage"
    charge_current:
      name: "Charge Current"
    precharge_current:
      name: "Precharge Current"

text_sensor:
  - platform: sy6970
    sy6970_id: pmu
    bus_status:
      name: "Power Source Type"
    charge_status:
      name: "Charging Status"
    ntc_status:
      name: "Battery Temperature"

binary_sensor:
  - platform: sy6970
    sy6970_id: pmu
    charging:
      name: "Battery Charging"
    vbus_connected:
      name: "VBUS Connected"
    charge_done:
      name: "Charge Done"

Advanced Configuration

The SY6970 provides several configuration methods that can be called from automations or scripts:

# Example automation to adjust charging parameters
automation:
  - trigger:
      - platform: homeassistant
        event: start
    then:
      - lambda: |-
          // Set input current limit to 1500mA
          id(pmu).set_input_current_limit(1500);
          // Set charge target voltage to 4200mV
          id(pmu).set_charge_target_voltage(4200);
          // Set charge current to 1000mA
          id(pmu).set_charge_current(1000);
          // Enable charging
          id(pmu).set_charge_enabled(true);

Available Methods

• set_input_current_limit(uint16_t milliamps) - Set the input current limit (100-3200mA in 50mA steps)
• set_charge_target_voltage(uint16_t millivolts) - Set the target charging voltage (3840-4608mV in 16mV steps)
• set_charge_current(uint16_t milliamps) - Set the fast charge current (0-5056mA in 64mA steps)
• set_precharge_current(uint16_t milliamps) - Set the precharge current (64-1024mA in 64mA steps)
• set_charge_enabled(bool enabled) - Set battery charging enabled/disabled
• set_led_enabled(bool enabled) - Set status LED to enabled/disabled
• set_enable_adc_measure(bool enabled) - Enable ADC measurements

Technical Details

The SY6970 is an I²C controlled battery management IC with the following features:

• Single-cell Li-Ion/Li-Polymer battery charger
• Wide input voltage range: 4.5V to 14V
• Programmable charge current up to 5A
• Programmable charge voltage up to 4.608V
• Battery over-temperature protection via NTC thermistor
• Automatic power path management
• Built-in ADC for voltage and current monitoring
• Status LED output

Register Implementation

The component directly implements the SY6970 register protocol:

• REG_0B: Bus and charge status (bits 7:5 for bus type, bits 4:3 for charge state)
• REG_0E: Battery voltage (base 2304mV, 20mV steps)
• REG_11: VBUS voltage (base 2600mV, 100mV steps)
• REG_12: Charge current (50mA steps)
• REG_00-07: Configuration registers for current limits, charge parameters, and safety timers

See Also

• SY6970 Datasheet
• Sensor Component
• Binary Sensor Component
• Text Sensor Component
• I²C Bus