A $35 UPS board adds a single 18650 battery to a Raspberry Pi Zero, providing automatic backup power when the main supply is interrupted.
ACE Design Studio, a Shenzhen-based hardware maker, has introduced the Pi-Ener-lite, a UPS board designed specifically for the Raspberry Pi Zero family. The board combines a Pi Zero with a single 18650 battery to provide backup power during mains interruptions without requiring a separate battery pack or additional cabling. Listed on Tindie, it provides a compact, Pi Zero-specific alternative to general-purpose UPS boards designed for larger Raspberry Pi 4 and Pi 5 systems.
The Pi-Ener-lite attaches to the underside of a Raspberry Pi Zero using seven spring-loaded pogo pins that carry both power and I²C data. This leaves the Pi’s 40-pin GPIO header available for additional hardware mounted above it. A single flat-top 18650 lithium-ion cell provides the backup supply and is charged through the board’s USB Type-C port, which also supplies power to the Pi. During normal operation, the board powers the Pi from the external supply while charging the battery. If the main supply is interrupted, it switches to battery power without restarting the Pi or interrupting its operation. A DS1307 real-time clock keeps track of time independently, with a CR1220 coin cell providing backup power even when both the external supply and 18650 battery are disconnected.
The board charges the 18650 cell at up to 1A from a 5V input and can deliver as much as 2.5A at 5.1V to the Raspberry Pi Zero. A CW2015 fuel-gauge IC monitors the battery, with specified accuracy of ±2% for remaining charge and ±3mV for battery voltage. This allows software on the Pi to track the battery level and provide warnings before the backup supply is depleted. Protection circuitry covers overcharging, excessive discharge, overcurrent and short circuits. A dedicated detection switch monitors the external power input and automatically triggers the changeover between external and battery power when the supply is connected or removed.
Most Raspberry Pi UPS boards are designed around the higher power requirements of larger models such as the Pi 4 and Pi 5, often using the 40-pin GPIO header for power and connectivity. This can occupy the header and make it difficult to use another HAT that requires access to those pins. The Pi-Ener-lite instead targets the lower-power Pi Zero family, using a single 18650 cell and pogo pins beneath the board. This leaves the GPIO header free for a sensor HAT, display or other GPIO-based expansion hardware.
ACE Design Studio lists the Pi-Ener-lite on Tindie for $35, with shipping starting at $9. The board does not include the Raspberry Pi Zero, 18650 battery or CR1220 cell required for the RTC. The manufacturer had not specified the board’s final dimensions at the time of writing, so users designing a custom enclosure may need to wait for confirmed measurements. The developer, using the handle linshuqin329, has published Python software, setup information and STL files for a 3D-printed enclosure on GitHub. As an independently developed maker product, buyers should also consider the level of support available compared with accessories from larger Raspberry Pi hardware vendors.
For Raspberry Pi Zero projects that need to remain operational during power interruptions, the Pi-Ener-lite offers a compact backup-power option without occupying the GPIO header. Its underside-mounted design keeps the top of the board available for HATs and other peripherals, while buyers outside the manufacturer’s market will need to account for shipping, taxes and import costs in addition to the $35 board price.
For more information, click here.
