Choosing the correct power supply for our Raspberry Pi devices seems simple, but we must also pay attention to it. Making the wrong choice could lead to reduced device functionality and may also result in severe hardware damage. Here, we will advise you on how to power your Raspberry Pi devices correctly.
The Power Requirements of Raspberry Pi
The output voltage and current are the most important aspects we must consider for any power supply selection. A Raspberry Pi generally operates at a 5V voltage. However, the current requirements can vary from 2.0A (2000mA) for older models to a minimum of 3.0A (3000mA) for the Raspberry Pi 4. More information is listed below for the voltage and current requirements for the power supply.
Voltage Requirements For The Power Supply
Raspberry Pi 1 and 2: 5 Volt
Raspberry Pi 3: 5 Volt
Raspberry Pi 4 and latest version: 5.1 Volt
Current Requirements For The Power Supply
Raspberry Pi 1 and 2: more than 1.8 Ampere
Raspberry Pi 3: more than 2.5 Ampere
Raspberry Pi 4 and latest version: more than 3 Ampere;
| Raspberry Pi Model | Voltage | Recommended Power Supply Current Capacity |
|---|---|---|
| Raspberry Pi 4B, 400 | 5V | 3A |
| Raspberry Pi 3B+/3B/3A+ | 5V | 2.5A |
| Raspberry Pi 2B/1B+ | 5V | 1.8A |
| Raspberry Pi 1B | 5V | 1.2A |
| Raspberry Pi 1A A+ | 5V | 700mA |
| Raspberry Pi Zero / Zero W | 5V | 1.2A |
| Raspberry Pi Zero 2W | 5V | 2A |
Suppose we adopt a power adapter that cannot provide sufficient current or does not satisfy the quality standards to charge the Raspberry Pi. In that case, a low-voltage warning will likely appear at the top of the Raspberry Pi’s screen. Moreover, you may also see a rainbow-colored square or a flashing lightning bolt icon on some older Raspberry Pi models.
Undervoltage can also bring various issues to the Raspberry Pi, such as SD card corruption, CPU throttling on the Raspberry Pi, problems with connected peripherals, and random system crashes. However, generally speaking, input undervoltage is unlikely to cause permanent damage to the Raspberry Pi.
Once the device is shut down and restarted, the Raspberry Pi should be able to resume regular operation.
Raspberry Pi low voltage warning
The Raspberry Pi displays a low-voltage warning when the voltage falls below a certain threshold. This is usually indicated by a yellow lightning bolt symbol at the display screen’s top-right corner. When you see this symbol, it generally means that the Raspberry Pi is not receiving sufficient voltage to operate reliably.
In extreme cases, this could lead to erratic behavior, data corruption, or even hardware damage.
Here are some common reasons for the low-voltage warning and potential solutions:
- Insufficient Power Supply: The power adapter might need to provide more power. Ensure you use an appropriate power supply for your Raspberry Pi model. For example, a Raspberry Pi 4 typically needs a 5.1V/3A USB-C power supply.
- Low-Quality Cable: The micro USB or USB-C cable may need to be of better quality or shorter, causing a voltage drop.
- Too Many Peripherals: If you have connected too many USB peripherals that draw power, the total power consumption may exceed what the power supply can deliver.
- Poor Quality Power Source: If you are using a battery pack or an alternative power source, it might need more voltage consistently.
Potential Solutions:
- Check the Power Supply: Use a power supply that meets the specifications of your Raspberry Pi model.
- Check the Cable: Try a different, preferably shorter, and high-quality, USB cable to connect the power supply to the Raspberry Pi.
- Reduce Load: Disconnect USB peripherals and see if the warning goes away. You can then add them back individually to identify the one causing the issue.
- Powered USB Hub: If you need to connect multiple power-hungry peripherals, consider using a powered USB hub with its power supply.
- Voltage and Current Monitor: Tools are available to monitor the voltage and current supplied to the Raspberry Pi. This can help you diagnose if the power supply or cable is the issue.
- Check Connections: Ensure all connections are secure, as loose connections can cause voltage drops.
- Check for Software Issues: Rarely, software configurations or active processes might be demanding too much from the CPU, causing the power supply to struggle. Make sure there are no such software issues.
- Check Power Source Quality: If you’re using a non-standard power source, like a battery pack, ensure it can deliver the required voltage and current for extended periods.
- Update Firmware: Sometimes, firmware updates fix power management issues, though this is less likely the cause.
Connector Types: Micro USB or USB-C
The type of connector your Raspberry Pi uses depends on the model you have. Some older models typically use the Micro USB connector. For example, the recommended method to charge Raspberry Pi Zero 2/Pi 3 is via the Micro-USB port, while for Raspberry Pi 4, the recommended and easiest way to power the devices is via the USB-C port on the side of the unit.
Raspberry Pi 1 and 2: Micro USB
Raspberry Pi 3: Micro USB
Raspberry Pi 4 and Latest version: USB-C
Impact of Connected Cable
The length of the cable can significantly affect the power supply quality. Shorter cables usually result in the issues of less voltage drop, ensuring consistent power delivery to our device and providing the best protection. Additionally, when choosing the cables, it’s best to opt for products from reputable companies, as their products are more resistant to bending, compression, or mechanical damage.
We should also note that the power cable for the Raspberry Pi 4 should be compatible with a power adapter that can supply more than 3A current; otherwise, the cable might get damaged due to excessive current, or the board’s performance could decline due to insufficient power.
Official or Third-Party Power Supply
The Raspberry Pi Foundation offers an official power supply designed for different kinds of Raspberry Pi’s specific requirements. However, High quality is not solely the domain of original manufacturer accessories.
Some third-party suppliers can also provide your Raspberry Pi with high-quality and highly compatible power adapter accessories if we choose them carefully. At StablePSU, We have consistently supplied third-party Raspberry Pi power adapters designed through ODM for distributors worldwide.
Conclusion
Through our regular study of Raspberry Pi knowledge, from understanding the voltage and current specifications to the cables’ length and awareness of safety features, these factors are crucial in choosing the correct power adapter for the Raspberry Pi.
