21700 UPS HAT (E) for Raspberry Pi 5/4/3

This is the Waveshare UPS (Uninterruptible Power Supply) HAT (E) for Raspberry Pi 5, Pi 4 and Pi 3, offering a stable 5V up to 6A via the high-power buck converter. It's a useful solution for short-term power backup to protect against power cuts, or even for those who wish to move their project between different power supplies.

The design accepts four 21700-size Lithium-ion batteries (not included), providing more potential capacity and run time of the UPS. It features built-in Li-ion battery bi-directional fast charging (charging via USB-C up to 40W PD) with onboard monitoring for voltage, current, and power via I2C. The HAT supports simultaneous charging and discharging, and can display battery levels directly in Raspberry Pi OS via software.

The board connects via high-current pogo pins and includes onboard protection circuits for overcharge, over-discharge, overcurrent, and short circuit events. It also features LED indicators and an onboard MCU to manage power detection and automatic booting. A USB-A output port provides a handy 5V output.

The board ships with an acrylic protection panel and fixings. Raspberry Pi and 21700 batteries not included.

Features

• UPS HAT for Raspberry Pi 5/4/3B+/3
• Provides 5V power output up to 6A
• Connects to the underside of the Raspberry Pi via pogo pins
• Supports 4x 21700 Li-ion batteries (not included)
• Simultaneous charging and discharging supported
• 5V output via onboard boost converter
• USB-C PD 40W fast charging
• Real-time voltage, current, and power monitoring via I2C
• Battery level display supported in Raspberry Pi OS
• Onboard MCU for power detection and auto-boot
• Battery protection: overcharge, over-discharge, overcurrent, short circuit
• LED indicators show battery status
• USB-A output port

Specifications

Output voltage	5V
Output power	5V 6A
Control bus	I2C
Battery support	21700 rechargeable Li-ion battery
Charger support	5V USB-C
Current capacity	5000mAh (Standard)
Dimensions	56 × 88mm
Mounting hole size	3.0mm

Resources

• Product Wiki

Important notes

• Do not charge when the battery is connected reversely. Reversing the battery connection may damage the battery protection chip.
• When assembling the battery, please follow the V1-V2-V3-V4 order to install. Otherwise, the reverse connection may turn on the warning indicator. The disassembled battery needs to be connected to the charger to charge in order to activate the output.
• After replacing the battery, it needs to complete several full charge/discharge cycles, so that the chip automatically calculates the battery parameters, and the capacitance is more accurate.
• The actual output current of the module can be up to 10A, due to heat dissipation reasons, it is recommended that the use of no more than 6A, and the use of larger currents should be added to the active cooling.
• Due to the battery type and temperature effects, the battery capacity may be inaccurate, to determine whether the voltage is charged or not should be based on voltage values.

Safety precautions

• Lithium‑ion and lithium‑polymer batteries can be hazardous if used or charged incorrectly, potentially causing fire, injury, or property damage.
• Always check battery polarity before charging or discharging. Never connect the battery in reverse, and only use suitable, good‑quality chargers or charging panels.
• Do not mix old and new batteries, or batteries from different manufacturers.
• Ensure the battery specifications are compatible with the expansion board.
• Lithium batteries have a limited service life and degrade over time. Replace batteries once they reach their rated cycle life or after two years of use, whichever comes first.
• Store batteries carefully, away from flammable or explosive materials, and keep them out of reach of children.

Package Contents

• 1x Waveshare UPS HAT (E)
• 1x Acrylic protection plate
• 1x Screw pack

Raspberry Pi and 21700 batteries not included