How to Fix Raspberry Pi "Undervoltage Detected" Warnings

Ben
Ben
@benjislab

Seeing the "Undervoltage detected" warning on your Raspberry Pi can be concerning. This warning indicates that your Raspberry Pi is not receiving enough power, which can lead to instability, crashes, and even potential hardware damage. In this guide, we'll explain what causes undervoltage warnings, how to diagnose the issue, and the steps you can take to fix it.

What Causes Undervoltage Warnings?

Undervoltage warnings occur when the voltage supplied to the Raspberry Pi drops below 4.63V. This can be caused by several factors, including:

  • Using a power supply that does not provide enough current
  • Poor quality USB cables
  • Excessive power consumption from connected peripherals
  • Faulty power supplies

Identifying Undervoltage Warnings

Visual Indicator

If you are using a monitor with your Raspberry Pi, you might see a small lightning bolt symbol in the top-right corner of the screen. This is an indication of an undervoltage condition.

Command Line Check

You can also check for undervoltage warnings using the command line. Open a terminal and use the following command:

vcgencmd get_throttled

The output will be a hexadecimal number. If the output includes 0x50000, it indicates that undervoltage has been detected.

Log File Check

Another way to check for undervoltage warnings is by looking at the system logs. Use the following command to view the logs:

dmesg | grep -i voltage

Look for messages indicating undervoltage conditions.

Fixing Undervoltage Issues

Use a Proper Power Supply

One of the most common causes of undervoltage is using a power supply that does not meet the requirements of the Raspberry Pi. Ensure you are using a 5V power supply that can provide at least 2.5A for Raspberry Pi 3 or earlier models, and 3A for Raspberry Pi 4.

Use High-Quality Cables

Cheap or poor-quality USB cables can cause significant voltage drops. Use a high-quality, thick-gauge USB cable to minimize resistance and ensure your Raspberry Pi receives adequate power.

Reduce Power Consumption

If you have multiple peripherals connected to your Raspberry Pi, they might be drawing more power than the supply can handle. Try disconnecting unnecessary peripherals or using a powered USB hub to offload power requirements from the Raspberry Pi.

Monitor Power Supply Performance

Use a USB power monitor to measure the voltage and current being supplied to your Raspberry Pi. This can help you identify if your power supply or cable is insufficient.

Software Solutions

Sometimes, software settings can help manage power consumption better. Ensure your Raspberry Pi is running the latest firmware and operating system updates, as these can include improvements to power management.

Conclusion

Addressing undervoltage warnings on your Raspberry Pi is essential to maintaining its stability and performance. By ensuring you use a proper power supply, high-quality cables, and managing the power consumption of connected peripherals, you can prevent undervoltage conditions and keep your Raspberry Pi running smoothly. Regularly checking for undervoltage warnings and taking proactive steps can save you from potential headaches and hardware issues in the future.