General discussion • Power Adaptor for Raspberry Pi 4 Model B and Servo HAT

Hey guys,

I am stumped by my ongoing power management.

So I am using a Levono Adaptor for my Raspberry Pi 4 Model B and servo HAT which is running 2 servo motors and an axial fan.

The Lenovo Adaptor can run in modes, 20 V=3.25 A/ 15 V=3 A/ 12 V=3 A/ 9 V=2 A/ 5 V=2 A. I also use a splitter to split the power between the Raspberry Pi and servo HAT.

The Raspberry requires 5 V 3 A while the servo HAT needs also 5 V 3 A. Total wattage required should be 30 W.

Here is where I am overly confused.

Many in work told me that the adaptor cannot power the setup because the adaptor can only give 2 A when in 5 V, they count with a constant voltage of 5 V.

I told them that I used the ampere 3 A to count and by the logic, it should work.

And it did.

When I asked why it worked, many cited that it is just dumb luck.

So I come to this forum hoping to find a proper explanation instead.

Because for my next phase, I am required to use a servo of 9 V 3 A and I have no idea how to calculate, either using constant V or constant A?

Statistics: Posted by JONLEE — Fri Jun 13, 2025 2:58 am

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