DC UPS (Lithium)

Li-Ion-powered DC-output uninterruptible power supply

What is it?

DC UPS is a lithium battery-powered uninterruptible power supply, which can provide backup power to devices like routers, switches, modems, single board computers, etc.

In contrast to commercially available UPSes, it uses off-the-shelf 18650 Li-Ion cells and outputs DC voltage directly.
This is significantly more efficient than providing AC power through an inverter.

The DC UPS provides backup power in a power outage without any interruption.
So called “Offline UPS” will have a short switching delay/interruption in power delivery, which can influence sensitive devices. Traditional “Online UPS” are expensive and waste a lot of power internally.

DC UPS size in comparison to a commercially available lead-acid UPS


  • 3 DC outputs
  • Selectable output voltage (9V/12V/12.5V/15V)
  • USB-C power output (5V only, 3A)
  • Builtin, easy to replace batteries (2x Li-Ion 18650)
  • Builtin Prometheus-exporter with comprehensive metrics
  • Open Source firmware (ESP32-based, esp-idf framework)
  • Easy software updates via rear USB port

Prometheus exporter

Integrated prometheus exporter provides a modern API to monitor temperatures, voltages, etc. via tools like Grafana:

Grafana dashboard, showing DC UPS graphs