qUPS-P-SC: UPS HAT for Raspberry Pi with Ultra Durable Supercapacitor

Power outages are no longer a threat. The qUPS-P-SC can handle short interruptions without an unexpected stop. For extended outages, it provides the critical time your Raspberry Pi needs for a graceful shutdown. Long-lasting, maintenance-free, environmentally friendly. Operates reliably across a wide temperature range.

Learn About Our Approach

Create a UPS solution for Raspberry Pi or compatible product, which is durable, has low carbon footprint, and can be used in harsch environment.
As the battery is the bottleneck of the tradional UPS solutions for these requirements, we have chosen SuperCapacitor for energy storage. It has extra high charge cycle rate, and wide operational temperature range. It is much greener product.

Why does backup time decrease disproportionately under high loads (e.g., Pi 5)?

Under heavy loads, a "double-bind" effect occurs. To maintain a stable 5.2V output, the qUPS must draw increasingly more current from the capacitor as its voltage drops. This process has its limits: due to the rising current demand, the system's critical voltage threshold "deteriorates," meaning the shutdown occurs at a higher voltage level. Consequently, under high loads, a significant portion of the energy stored in the capacitor remains inaccessible, drastically shortening the backup time. This physical constraint can be countered using the qUPS Extender module, which slows down the voltage drop by multiplying the total capacity.

What is the critical voltage level and the hardware current limit?

The critical voltage level is the threshold down to which the internal DC-DC converter can still extract energy from the capacitor. This boundary is defined by the module's hardware current limit of maximum 7.5A (typically 6.5A). As the Raspberry Pi’s power consumption increases, this limit "consumes" the available headroom much sooner:

Low load (e.g., Pi 2): The converter requires very little current, allowing the critical level to improve down to 1.2V – meaning the capacitor can be almost completely discharged. Consequently, the Pi 2 achieves a backup time of 168 seconds under no load, and 80 seconds under maximum load.

High load (e.g., Pi 5): The system hits the 7.5A limit much earlier, at a critical voltage of 2.0V – 2.2V. Because this "worsening" threshold makes the lower voltage ranges of the capacitor inaccessible, the backup time drops to 8 seconds under the Pi 5's maximum load, however it is still 74 seconds, if there is no load on Pi5.