Skip to main content

ESP32-S3 PowerFeather

Features & Specifications


  • Board Dimensions: 65 mm L x 23 mm W x 7 mm H
  • Feather-compatible format, Feather Wings support
  • Board Features
    • USB-C connector
    • Two 2.5 mm mounting holes
    • Two 1x16 2.54 mm header pin holes
    • Thermistor pin hole
    • 2-pin JST PH Li-ion/LiPo battery connector
    • 4-pin JST SH STEMMA QT connector
    • Green user LED
    • Red charger status LED
    • User button
    • Reset button
    • On-board PCB antenna


Compute Resources

  • 240 Mhz Dual-Core Xtensa LX7 Processor
  • RISC-V / FSM Ultra Low Power Coprocessor
  • 8 MB Quad-SPI Flash
  • 2 MB Quad-SPI PSRAM
  • 512 KB SRAM
  • 16 KB RTC SRAM

Power Management

  • Supply Monitoring
    • Current measurement
    • Voltage measurement
    • Good supply detection
  • Supply Management
    • Set maintained supply voltage (can be used to set MPP voltage)
  • Battery Monitoring
    • Voltage measurement
    • Temperature measurement
    • Current measurement (charge/discharge)
    • Charge estimation
    • Health & cycle count estimation
    • Time-to-empty and time-to-full estimation
    • Low charge, high/low voltage alarm
  • Battery Management
    • Enable/disable charging
    • Set max charging current
  • Others
    • 3V3 enable/disable
    • VSQT enable/disable
    • FeatherWing enable/disable via EN pin
    • Power States
      • Ship mode
      • Shutdown mode
      • Power cycle
    • Battery Protections
      • Undervoltage Detect @2.2 V, Release @2.4 V
      • Overvoltage Detect @4.37 V, Release @4.28 V
      • Overcurrent protection @3A
      • Trickle charging safety timer @1 hr
      • Temperature-based charging current reduction based on JEITA, cutoff at 0 °C and 50 °C.



  • 2.4 GHz Wi-Fi 802.11b/g/n on PCB antenna
  • Bluetooth 5 LE + Mesh on PCB antenna


  • USB 1.1 Full-Speed OTG on USB-C connector
  • I2C on STEMMA QT connector

Pin Holes

  • 23 I/O on the two 1x16 2.54 mm pitch header pin holes
    • All digital input and output capable
    • All UART, I2C, SPI, I2S, SDIO, PWM, CAN, RMT, Camera, LCD capable
    • 6 analog input capable
    • 5 touch input capable
    • 12 RTC capable (deep sleep pin hold, wake-up source)
  • Semitec 103AT input on thermistor pin hole



  • 5 V, 2 A max on VUSB USB-C connector
  • 5 V - 18 V, 2A max on VDC header pin
  • 4.2 V max, 2 A max on BATP and BATN JST PH Li-ion/LiPo battery connector


  • 3.3 V, 1 A max shared between board, 3V3 header pin and VSQT STEMMA QT connector
  • 3.3 V - 4.2 V, 3 A max shared between board and VBAT header pin
  • 5 V - 18 V, 2 A max shared between board and VS header pin

Current Consumption

Power StateBATP Current
Deep-Sleep, Fuel Gauge Enabled (Initial)26 μA
Deep-Sleep, Fuel Gauge Enabled (Settled)18.5 μA
Deep-Sleep, Fuel Gauge Disabled18 μA
Ship Mode, Fuel Gauge Disabled1.5 μA
Shutdown Mode, Fuel Gauge Disabled1.4 μA

Pins & Signals

ESP32-S3 PowerFeather pinout


These are signals routed to the ESP32-S3 GPIO pins.

Free IO

IO signals not connected to anything on-board; user code is free to configure and use these for any purpose within their respective GPIO capabilities. Note that the Description and Name are only for compatibility with the Feather specification, and does not strictly define the functionality of the IO. For example, there are other pins that can be used as analog inputs outside of A0 - A5, such as D8 which is ADC1_5. Another example is that IO other than MOSI, MISO and SCK can also be used for SPI - it's not limited to these ones.

NameDescriptionDigitalAnalog InputRTCTouchJTAG
A0Analog Input 0GPIO10ADC1_9RTCIO10TOUCH10
D5Digital Input/Output 5GPIO15ADC2_4RTCIO15
D6Digital Input/Output 6GPIO16ADC2_5RTCIO16
D7Digital Input/Output 7GPIO37
D8Digital Input/Output 8GPIO6ADC1_5RTCIO6TOUCH6
D9Digital Input/Output 9GPIO17ADC2_6RTCIO17
D10Digital Input/Output 10GPIO18ADC2_7RTCIO18
D11Digital Input/Output 11GPIO45
D12Digital Input/Output 12GPIO12ADC2_1RTCIO12TOUCH12
D13Digital Input/Output 13GPIO11ADC2_0RTCIO11TOUCH11
TX0Serial Log OutputGPIO43
  • Digital - IO that can output or accept input of 3.3 V digital logic; supports UART, I2C, SPI, I2S, SDIO, PWM, CAN, RMT, Camera, and LCD peripheral.
  • RTC - IO that can hold output state during deep-sleep; or be used as a wake-up source from deep-sleep.
  • Touch - IO that can be used as capacitive touch input.
  • Analog Input - IO that can read analog signals; X, Y in ADCX_Y denotes the ADC number and channel respectively.
  • JTAG - IO that can be used for JTAG debugging.

User-Managed Fixed IO

IO signals connected to a component on-board, limiting its use. For example, it does not make sense to use BTN as UART TX due to being connected to a button, even though it is technically capable of doing so. User code is still in control in terms of configuring and using these IO.

ALARMBattery Fuel Gauge Alarm InputGPIO21RTCIO21
INTBattery Charger Interrupt InputGPIO5RTCIO5
BTNUser Button InputGPIO0RTCIO0
LEDGreen User LED OutputGPIO46RTCIO7

SDK-Managed Fixed IO

IO signals connected to a component on-board, whose configuration and use is managed by the SDK. User code should not configure and use these IO, as doing so can cause faulty behavior.

USB_DPUSB Data Positive
USB_DMUSB Data Negative
PGPower Supply Good Indicator Input
3V3_EN3V3 Enable Output
VSQT_ENVSQT Enable Output
EN0Board Enable Output

Special Function

Signals not routed to the ESP32-S3 GPIO pins, or are routed to other integrated circuits on-board such as the battery charger and fuel gauge.

CHGBattery Charger Status LED
RSTESP32-S3 Module Reset
QONShip Mode Exit
TSSemitec 103AT Thermistor Input
ENFeather Wing Enable Output

Power Input

Supplies power to the board.

BATNLi-ion/LiPo Negative Terminal
BATPLi-ion/LiPo Positive Terminal
VUSB5V USB Power Input
VDC3.8 V - 18 V Header Pin Input

Power Output

Powers loads connected to the board. Please don't connect power supplies to these.

VBAT3.7 V - 4.2 V Battery Output
VS3.8 V - 18 V Supply Voltage; Higher of VDC and VUSB
3V3Header Pin 3.3 V Output


0 V reference for the components on-board, input power supplies and connected loads.

GNDGround Pin


Feather Differences

While ESP32-S3 PowerFeather is largely compatible with the Adafruit Feather ecosystem, it has has a few deviations from the Feather specification.

  • EN Behavior

    On standard Feather boards, the EN pin is connected to the enable pin of the on-board 3.3 V regulator. Pulling EN low means disabling the 3.3 V regulator and everything powered from it.

    On PowerFeather, EN is connected to an ESP32-S3 IO pin. User code can read the state of this pin and act accordingly, i.e. it can disable the 3V3 and VSQT load switches and put itself to deep-sleep to emulate behavior on standard boards; or it might do something completely different.

    Furthermore, the ESP32-S3 itself can pull EN low if user code needs to disable connected Feather Wings.

  • QON Pull-Up

    QON replaces AREF on ESP32-S3 PowerFeather, and is normally pulled high up to 5 V. Make sure when connecting Feather Wings that it is able to handle this voltage on its AREF pin, or the Feather Wing does not use AREF at all.

    If this is an issue, QON can be removed by breaking a solder bridge labeled B2.

  • VS Up to 18 V

    On standard Feather boards, the pin at the same position as VS is the 5 V output (there is no on-board 5 V regulator, the 5 V comes from the USB supply). On PowerFeather, VS outputs either VUSB or VDC, whichever has a higher voltage. Since VDC can be up to 18 V, this means that VS can also be up to 18 V.

    Keep this in mind if using a power supply with voltage higher than 5 V on VDC, as it might destroy Feather Wings that only expects 5 V on its VS/5V pin.

Soldering Headers

Due to the ESP32-S3 module's size, some of the header holes are awfully close its pads. This means that in these areas, there is a risk of shorting a hole with a pad when soldering headers.

Header pins close to ESP32-S3 pads

This is especially dangerous with VDC, since it is a high voltage power input (up to 18 V) that would most likely fry the ESP32-S3 if it comes in contact with one of its pads. It would be wise to check for shorts using a multimeter after soldering headers, just to be safe.

Battery Polarity

The wiring polarity for batteries with JST-PH connectors is not standardized. Please make sure the batteries you use are wired with the correct polarity - it is printed on the silkscreen!

Proper battery polarity

Miscelleanous Questions

  • Can VUSB and VDC be plugged in at the same time?

    VUSB and VDC are or'ed with schottky diodes, so it's safe to have them plugged in at the same time. The schottky diodes ensure that current does not flow from VDC to VUSB or vice versa depending on which is higher. The higher voltage of the two supplies PowerFeather; if they are around the same voltage, they share the current load for PowerFeather and all connected devices.

  • Can power be drawn by the board or connected loads while charging?

    PowerFeather uses a charger IC that implements a power path, so it is safe to have PowerFeather and connected devices draw power while charging the battery. Furthermore, the power path allows the battery to supplement VUSB or VDC during load power spikes to prevent brownouts. Also, if there is VDC or VUSB, but there is no battery or the battery is fully depleted, VBAT is still regulated to 3.7 V.

  • Does ESP32-S3 PowerFeather support LiFePO4/LFP?

    The board as a whole does not support LiFePO4 batteries. While the charger IC supports LiFePO4, the fuel gauge IC does not. Furthermore, PowerFeather uses a linear regulator to provide the 3.3 V power rail, which won't function properly under a LiFePO4 battery with nominal voltage of 3.2 V.

  • What do you mean by near/pseudo-MPPT?

    PowerFeather does not support 'true' MPPT in the sense that it does not do full tracking of the panel's I-V curve. However, the panel MPP voltage can be set, and the charger IC will dynamically regulate charging current to prevent the panel voltage from collapsing below it. This provides near/pseudo-MPPT performance, since the MPP voltage for a typical panel remains roughly the same across various illumination levels.

    For more details, please read this Adafruit design note for one of their solar chargers that uses the same dynamic charging current regulation technology. However, the advantage of PowerFeather compared to their solar charger is that their solar charger has a fixed MPP voltage at 4.5 V, while for PowerFeather it can be adjusted in firmware up to 16.8 V.


Current Measurements

These are measurements for the figures in Current Consumption. These were measured using Nordic Power Profiler Kit II (a.k.a PPK2) acting as a battery @3.7 V plugged into BATP and BATN; and with no external supply (VBUS or VDC).

Deep Sleep, Fuel Gauge Enabled (Initial)Deep Sleep, Fuel Gauge Enabled (Settled)
Fuel gauge enabled, initial current measurement trace
The fuel gauge initially samples around every ~1 s, with each sample registering a current spike to up ~5 mA.
Fuel gauge enabled, settled current measurement trace
The fuel gauge samples settles down to around every ~2 s, with each sample registering a current spike up to ~50 μA.
Deep Sleep, Fuel Gauge DisabledShip Mode, Fuel Gauge DisabledShutdown Mode, Fuel Gauge Disabled
No fuel gauge current measurement traceShip mode current measurement traceShutdown mode current measurement trace

You can download the raw traces obtained from PPK2 using the links below, and open them with your nRF Connect Power Profiler Software.

Key Components

Microcontroller & WiFi + Bluetooth LE SoCEspressifESP32-S3-WROOM-1
Battery ChargerTexas InstrumentsBQ25628E
Battery Fuel GaugeOnsemiLC709204F
3.3 V RegulatorTorexXC6220


ESP32-S3 PowerFeather product photo 1ESP32-S3 PowerFeather product photo 4ESP32-S3 PowerFeather product photo 5ESP32-S3 PowerFeather product photo 2ESP32-S3 PowerFeather product photo 3