Low voltage warning. Please check your power supply
I’m getting this warning message on my Raspberry Pi 3b+.
I checked the voltage on the 5V header pin with a multimeter, and it was 4.83V, Raspberry Pi should be able to work on 4.75V. So I checked the online forums, apart from the voltage actually being low, some suggested that the warning could be triggered by an older micro SD card, and some suggested to upgrade/update the OS. So I first tried to update the system, and used the following command:
sudo apt-get update && sudo apt-get dist-upgrade -y
However, this did not solve the problem. I’m using an I.T.E Power Supply (5V, 3.0A), and before this I tried another one also rated 5V, 3.0A. Apart from this warning, the Pi seems to work fine.
Then I noticed that the little yellow lightening bolt sign isn’t on all the time, it showed up during power-up, and when I open an application. After this, the lightening bold is gone, but the warning message remains. So I again checked the voltage, and it did drop to 4.77V. As this was measured with a multimeter, and the drop is transient, it may have dropped below 4.75V, so the warning is legitimate. What is causing such a power drain is not clear. Even though it says it’s an I.T.E (Information Technology Equipment) Power Supply, perhaps it’s not as good, and isn’t regulated.