WSAL19739 – UPS HAT (C)/en

Documentation notice: This technical documentation was independently rewritten from an archived supplier source. Check technical details and commands against the product version and manufacturer documentation before use.

Summary

The UPS HAT (C) is an uninterruptible power supply for the Raspberry Pi Zero series. It provides stable 5 V output, manages LiPo battery charging via an integrated charge controller, and monitors voltage, current and state of charge over I2C.

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WSAL19739 – Uninterruptible Power Supply UPS HAT For Raspberry Pi Zero, Stable 5V Power Output

Technical overview

Connects to Raspberry Pi Zero / Zero 2W via spring pogo pins on the board.
ETA6003 charge manager with dynamic path management for stable battery charging.
TPS61088 boost regulator provides a regulated 5 V output.
INA219 measures voltage and current in real time over I2C; address per FAQ: 0x43.
S8261/FS8205 protection circuitry offers overcharge, overdischarge, overcurrent and short-circuit protection.
Supported battery: 803040 LiPo, 3.7 V, 1000 mAh (not included).
HAT dimensions: 65 × 30 mm, mounting hole 3.0 mm.
Micro USB port is the 5 V charging input; LED on while charging, off when fully charged.
Set the power switch to OFF before inserting the battery to avoid shorting the board.
After inserting a new or replaced battery, it must be charged first so the protection circuitry activates.

Commands and examples – verify before use:

sudo raspi-config
sudo reboot
sudo apt-get install p7zip
wget https://files.waveshare.com/upload/4/40/UPS_HAT_C.7z
7zr x UPS_HAT_C.7z -r -o./
cd UPS_HAT_C
python3 INA219.py
sudo apt-get install i2c-tools
sudo i2cdetect -y 1
sudo apt-get install python-smbus
sudo apt-get install python3-smbus

Notes and version constraints

The listed I2C address 0x43 comes from the FAQ section of the source; if the device is not detected, check pogo-pin contact and, if needed, solder the pin header.
If the battery does not work after first insertion, it must be charged for a while to activate the protection circuitry.
If the load draws too much current, the Pi may repeatedly reboot because available output current decreases as battery voltage drops (~1.8 A at full charge).
The capacity readout is derived from battery voltage and deviates from actual capacity while charging.
For operation with a larger battery (e.g. 5000 mAh), the voltage must remain 3.7 V; capacity itself is not a restricting factor, but no explicit confirmation exists for form factors other than 803040.
If 'No module named smbus' appears, install python-smbus or python3-smbus.

Source and revision record

UPS HAT (C) - Waveshare Wiki
Source revision: 87392
Captured: 2026-09-02T02:46:59+00:00
SHA-256: 2d6be09dc2f9db0ef374b4f737914df0c6c525e8fc1579bfe6c43fdc9e704a05