Whether you're using your Raspberry Pi in the home or in a remote location, such as for a weather station or wildlife camera, it will need a reliable electricity supply to work.

If you have a Raspberry Pi model and you're not quite sure how to power it for your project, read on to find out about the different ways you can supply electricity to these credit-card-sized computers.

Raspberry Pi Power Options

All Raspberry Pi computers since inception require 5V power, but the recommended amperage varies between models. Older (and also the smaller Zero) models require 2.5A or less while newer full-size models such as the Raspberry Pi 4 and Pi 400 need as much as 3A, especially if you're attaching extra peripherals or performing heavy tasks.

The table below shows the power requirements for each Raspberry Pi model.

Raspberry Pi Model

Voltage

Recommended PSU 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 1 A / A+

5V

700A

Raspberry Pi Zero / Zero W

5V

1.2A

Raspberry Pi Zero 2W

5V

2A

Raspberry Pi Pico (microcontroller)

1.8A–5.5V

1.2A

Using a power supply that doesn’t deliver enough current or meet the requirements otherwise will cause a low voltage warning to show at the top of the screen. Older models may show rainbow-colored squares or a flashing lightning icon instead.

Undervoltage can lead to issues such as SD card corruption, CPU throttling, problems with connected peripherals, and random crashes. Generally, undervoltage will not cause permanent damage to the Raspberry Pi.

1. Power Supply

The official Raspberry Power Supply
Image Credit: raspberrypi.com

The most common way to power a Raspberry Pi is by using a compatible USB mains power supply. The type of USB connector differs from model to model. Recent Raspberry Pi models have seen a shift from micro-USB to the USB Type-C connector.

If you already have a USB mains power supply that meets the recommended requirements, you can use it to power your Raspberry Pi without any hassle. Otherwise, you may be better off getting the official USB power supply from an approved retailer, just to save time and avoid any hitches.

The Raspberry Pi official power supply provides higher than normal USB voltage at 5.1 volts to prevent the issues caused by voltage drops in cables.

2. Power Bank

laptop charging from a laptop power bank

If you can’t or prefer not to power your Raspberry Pi from the mains, a compatible power bank will be the next best option. A power bank will especially come in handy for portable or always-on projects.

The power back doesn't have to supply exactly 3A. Amperage as low as 2.4A has been proven to be quite enough for the Raspberry Pi 4B in a lot of situations. But, if you are connecting keyboards, mice, and SSDs, you need a 3A power supply. You need to account for voltage drops, especially if you’re using generic cables. The Raspberry Pi usually triggers a low voltage warning at around 4.7V.

According to power measurements from Raspi.tv, the Raspberry Pi 4B uses about 640mA when watching 1080p video. That yields about 3.2W of electrical power when multiplied by the 5V input voltage.

The typical lithium-ion power bank has a nominal cell voltage of 3.7V. For a 20Ah power bank, this works out to a capacity of 74Wh. To calculate the hours this power bank will last, we divide this capacity (74Wh) by the power demand of the Raspberry Pi (3.2W, when watching a 1080p video).

Therefore, a 20,000mAh power bank should power the Raspberry Pi 4 for about 23 hours, when watching videos and under a low intensive load overall. This will be either less or more, depending on the CPU load and connected devices.

3. Uninterruptible Power Supply (UPS)

APC UPS on a desk
Image Credit: APC

An uninterruptible power supply (UPS) is a device that provides emergency backup power for computers and other devices.

Unlike a portable power bank, a UPS automatically powers on in the event of a mains power failure and typically has a smaller battery capacity. It is also usually more expensive than a power bank, but it can be helpful in the event of a power outage, in particular for projects that need to be always-on.

To use a UPS with a Raspberry Pi, you'll need to purchase a UPS HAT (Hardware Attached on Top) such as the PiJuice or Waveshare model. You will need to set the HAT up to kick in during an outage. Power from a UPS may last for anything from two to five hours, depending on the capacity.

4. General Purpose Input Output (GPIO)

raspberry-pi-gpio

The General Purpose Input Output (GPIO) header on the Raspberry Pi is a row of pins, either 26 or 40 in total, which can be used to interface between the Raspberry Pi and other electronic components. It can also be used to power the Pi.

You should note, however, that powering a Raspberry Pi via the 5V power pins on the GPIO can be tricky as it can lead to serious problems if done incorrectly. It may cause permanent harm to your Raspberry Pi. This method of powering the Raspberry Pi may be suited for more experienced users.

You will need to connect physical pin 2 or 4 to a 5V supply and pin 6 to ground (GND). You also need to make that your power supply is regulated and has overcurrent protection before hooking it up to the Raspberry Pi.

5. Power over Ethernet (PoE)

best cat 8 cables
Image Credit: Inara Prusakova/Shutterstock

Power over Ethernet, or PoE, is an increasingly popular method of supplying power to devices. It uses the spare pair in an Ethernet cable to carry both data and electrical current. This can be used as a convenient way to supply power to Raspberry Pis or other devices that require their own dedicated power source. Currently, the Raspberry Pi 3B+ and 4B are the only models that officially support Power over Ethernet (although others may work using a third-party PoE adapter).

To power a Raspberry Pi over Ethernet, you need a PoE HAT. You can use either the original Raspberry Pi PoE HAT (discontinued, but still available for purchase on Amazon) or the Raspberry Pi PoE+ HAT. The PoE+ HAT can deliver more power, and it’s the same price as the older version. The original PoE HAT however uses less power while idling and fits inside the official case, if those are important considerations for you.

Conclusion

There are many ways to power a Raspberry Pi. The most common way is by using a USB mains PSU, but there are other options such as PoE and portable power banks. Each method has its own pros and cons, so it's up to you to choose the best method applicable to your situation and your project demands.