As you can probably guess just from its small size and light weight, the Raspberry Pi does not use a lot of power. While it is nice to know that your Raspberry Pi will not be adding much onto your electric bill, exactly how much power does it actually consume? This can be tricky to answer and we need to rely on external devices, since power consumption can’t be accurately measured from software alone.
In this tutorial, we will go over the methods for measuring power consumption on the Raspberry Pi. This will cover a method for measuring CPU voltage, in case that is what you are after, as well as the total wattage that is being consumed to run the Raspberry Pi. We will also discuss why measuring power consumption for the Raspberry Pi is not as practical as it might be on laptops or battery powered devices.
In this tutorial you will learn:
- How to check wattage drawn by the Raspberry Pi
- How to check CPU voltage
- How to check circuit board voltage
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# – requires given linux commands to be executed with root privileges either directly as a root user or by use of
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How to Measure Power Consumption on Raspberry Pi
Unfortunately, it is not possible to get any meaningful measurement of power consumption via software on the Raspberry Pi. This is mostly because it does not use a battery like a laptop does. Laptops can use a utility such as powertop to tap into the information provided by the system battery in order to make assessments about the device’s power consumption. Our tutorial on measuring power consumption with PowerTop covers this in detail.
We can check the voltage of the CPU on Raspberry Pi by executing this command:
$ vcgencmd measure_volts
But this is probably not relevant for most users, since voltage does not really equate to power consumption, and it this output just tells us the voltage of the CPU. See also: How to check CPU frequency on Raspberry Pi
Let’s look at some other methods. One reliable way to accurately measure the wattage being drawn by the Raspberry Pi would be with a USB multimeter (sometimes called USB voltmeter or USB ammeter). This is a device that sits between the wall outlet and your Raspberry Pi, which means the power must pass through the USB multimeter in order to reach your Raspberry Pi. As the current passes through the device, it can measure the wattage and therefore give you information about the power consumption of your Raspberry Pi.
Such devices are readily available on Amazon and other online vendors by simply searching for “USB multimeter.”
Test Raspberry Pi Voltage
Another option we have is to measure the voltage of the Raspberry Pi circuit board. This does not really yield us power consumption, but can clue us into power supply problems by revealing the total voltage of the board. To perform the measurement, we can use a multimeter and place the pins on TP1 and TP2 (test point 1 and 2).
You will need to set the multimeter to 20 volts DC. Since the voltage range for these test points is 0.5 volts, the multimeter should reveal voltage in the range of 4.75 and 5.25 volts. If so, then your Raspberry Pi is properly powered.
In this tutorial, we saw how to check the power consumption on a Raspberry Pi system. Since the Raspberry Pi does not use a battery, we must rely on hardware methods to check its power consumption. We learned how to measure total wattage with a USB multimeter, and also check the voltage of the Raspberry Pi circuit board with an ordinary multimeter. This should give you all the information you need with regards to power consumption of your Raspberry Pi.