Interrupt Labs and Protectli Partner to Build a Hackable, Open Source UPS

Maker Ryan Walker, of Interrupt Labs, has teamed up with Protectli to design an open source uninterruptible power supply (UPS) — using 12 18560 batteries to keep DC-supplied devices ticking over in the case of a power outage.

"We've designed an open source UPS that redefines the relationship customers have with their electronics," Walker claims of the device, the design and firmware for which is being made available under a permissive open source license. "It uses 12 18650 upgradable batteries, an [Espressif] ESP32 to host a web server, [Raspberry Pi] RP2040 for general control, GPIO [General-Purpose Input/Output] to wire in external components, relays, and more."

While many UPS designs have to handle mains-voltage alternating current, Walker's design opts for something simpler: 12V direct current in, 12V direct current out — using, smartly, two different sizes of barrel-jack connector so you can't mix up which is which. Under normal conditions, the input power flows directly to the output — but if the input power goes missing, the UPS automatically switches to its bank of 18650 batteries until the input power supply comes back online.

The board has a selection of quality-of-life features above and beyond simply ensuring continued power, including an on-board 128×64 OLED display for local status and a web server running on the on-board Espressif ESP32 module with support for Network UPS Tools (NUT) for monitoring and control.

As an open-hardware device the firmware for both the ESP32 and the Raspberry Pi RP2040 microcontrollers are also being made available for users to hack and iterate upon, should a feature be found missing.

More information on the UPS design is available in the video embedded above, while schematics and source code have been published to GitHub under the MIT license; additional details, and a link to be alerted when development is complete and the commercial version is available, can be found on the Protectli website.