espresso_Charge_status

Python script for getting the state of Espresso Charge power bank

Device: https://us.espres.so/products/espresso-charge

Charge Battery Reader

A Python script to read battery telemetry from a Charge battery device over USB serial on Linux.

The device uses a Silicon Labs CP210x USB-to-UART bridge and communicates via a COBS-encoded binary protocol.

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Prerequisites

Hardware

• Charge battery device connected via USB

OS / Kernel

• Linux with the cp210x kernel module (included in most distributions by default)
• Verify it is loaded:

  lsmod | grep cp210x

• If missing, load it manually:

  sudo modprobe cp210x

Serial port permissions

By default, /dev/ttyUSB* devices require root or membership in the dialout group.

Add your user to the group (recommended):

sudo usermod -aG dialout $USER

Then log out and back in for the change to take effect.

Or for a one-off temporary fix:

sudo chmod 666 /dev/ttyUSB0

Python

• Python 3.7 or later
• pyserial library:

  pip install pyserial --break-system-packages

  Or inside a virtual environment:

  python3 -m venv venv
  source venv/bin/activate
  pip install pyserial

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Finding the device port

After plugging in the device, confirm it is detected:

lsusb | grep "10c4"
# Silicon Laboratories CP210x USB to UART Bridge

ls /dev/ttyUSB*
# e.g. /dev/ttyUSB0

For a stable path that survives reboots:

ls /dev/serial/by-id/
# e.g. usb-Silicon_Labs_CP2102_...-port0

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Usage

python3 readcharge.py

By default the script connects to /dev/ttyUSB0. If your device appears on a different port, edit this line near the top of the script:

with serial.Serial('/dev/ttyUSB0', baudrate=115200, timeout=2) as ser:

Example output

SOC: 97%  SOH: 83%
Voltage: 20.715 V  Current: 58 mA
Temp: 35.95 °C
Remaining: 4928 mAh / 5113 mAh
Time to empty: N/A min
Time to full:  Done
Power direction: SINK (charging)

Field reference

Field	Description
SOC	State of Charge — current charge level (%)
SOH	State of Health — battery condition vs new (%)
Voltage	Pack voltage in volts
Current	Charge/discharge current in mA
Temp	Battery temperature in °C
Remaining	Current usable capacity in mAh
Full capacity	Maximum capacity at current SOH in mAh
Time to empty	Estimated minutes of runtime remaining (N/A when charging)
Time to full	Estimated minutes until fully charged (Done when at 100%)
Power direction	SINK = charging, SOURCE = discharging

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Protocol notes

Parameter	Value
USB Vendor ID	10c4 (Silicon Laboratories)
USB Product ID	ea60 (CP210x)
Baud rate	115200
Framing	COBS-encoded, 0x00-terminated packets
Checksum	XOR of all payload bytes, appended before encoding
Capacity fields	16-bit little-endian
Voltage / current / temp / time fields	16-bit, byte-swapped then big-endian
Temperature conversion	raw × 0.1 − 273.15 (Kelvin → °C)