Power Limitations of the Geekworm UPS HAT

Power Consumption of the Raspberry

The different versions of the Raspberry have different power requirements (see link). If we look at the typical power consumption of a RPi4 we see that it needs around 600mA. If we add a safety margin to that, let's say 400mA, and add a USB SSD drive with 500mA peak consumption, we get something around 1.2A with peak 1.5A.

Compare this to the recommended power supplies, then you see that the safety margin is pretty high. One of the motivations for this comes from the RPi being very sensitive about voltage drops.

The Geekworm UPS HAT

And this is where the Geekworm UPS HAT shines. It keeps the output voltage at 5.0V even with high loads, so you most probably won't ever see the rainbow square, or get into other voltage-related problems.

If we now look at technical details of the Geekworm UPS HAT, then we see it is rated for 2.0A. The chip used (ETA1096) is rated even higher if cooled properly (3.0A), but since it doesn't have any cooling and we can't get rid of the heat (the mounting position is towards the RPi), I would say even the 2A are very optimistic.

Patrick Van Oosterwijck, who has created a UPS of his own, tested the chip and found that the chip heated up very much even at 1.5A.

Does this mean that the Geekworm UPS HAT is unusable?

As always, it depends.

• If you have a system with a large number of peripherals that does number crunching the whole time, then I would not suggest to use this UPS.
• But if you have a system that has e.g., one SSD and one other peripheral, runs as an MQTT server with an influxdb, with Bluetooth and WIFI turned off, then in my opinion you have a very good use case for this UPS.