Powering your Raspberry Pi with a battery is a popular choice for those who want to make their projects portable. In this tutorial, we’ll explore the process of powering a Raspberry Pi with a battery and provide guidance on how to do it correctly.
Choosing the Right Raspberry Pi
The first thing to consider when powering your Raspberry Pi with a battery is choosing the right model. While the latest Raspberry Pi 4 B is a powerful single-board computer with a quad-core processor, gigabit Ethernet, and support for two 4k displays, it also consumes a substantial 6.25Wh of power. If you want to maximize battery life, a better choice would be the Raspberry Pi Zero, which consumes almost seven times less power than the Raspberry Pi 4 B.
Calculating Battery Life
Once you’ve chosen the right Raspberry Pi, it’s time to calculate how long it can run on a given battery. To do this, you’ll need to know the rated amperage of your Raspberry Pi and the capacity of your battery. For example, if you have a single cylindrical 18650 lithium battery with 2200 mAh capacity, and your Raspberry Pi 4 B has a rated amperage of 1.25A, you would divide 2200mAh by 1.25A to get a battery life of only one hour and forty-five minutes.
Choosing the Right Battery Size
Using the calculations above, you can determine the battery size that you need for your device. For instance, a 1000mAh battery would be able to power a device with a rated current of 1000mA for one hour. Similarly, a 40,000mAh power bank would be able to power a 4A device for one hour, or a 1A device for 40 hours. It’s important to remember that you’ll need to consider your project’s power consumption and how long you need the device to be powered by a single charge.
Also read: The Best 5 Monitors For Raspberry Pi 4 In 2023
Things to Consider
When powering your Raspberry Pi with a battery, you’ll also need to consider the power consumption and efficiency of your DC/DC converter, which converts the 3.7V battery voltage to the 5V DC required by the Raspberry Pi. You’ll need to choose a good DC/DC converter carefully to ensure optimal battery life. Additionally, if you’re using a rechargeable battery, you’ll need a battery charge controller to regulate the incoming current and voltage to your batteries. This will prevent overcharging and prolong the lifespan of your batteries.
Battery Setups
There are three battery setups that you can use to power your Raspberry Pi. The first setup is the minimal setup, which involves connecting a TP4056 charge controller to a 3.7V lithium battery and then connecting the charge controller’s output to the 5V pin and ground of the Raspberry Pi Zero. While this setup is good for testing, it’s not recommended as a permanent solution since it can cause the Raspberry Pi to shut down prematurely when the battery level drops.
To solve this problem, you can use a MT3608 3.7V to 5V DC/DC converter that ups your 3.7V to standard 5V. Take the output from the charge controller, connect it to the converter’s input, and connect the output to the 5V pin of the Raspberry Pi. With this setup, you don’t have to worry about not making the most of your batteries and can avoid the need to disconnect the batteries every time you charge.
Another option is to use a dedicated battery management board, such as the Pi Supply PiJuice HAT. This board provides an integrated power management solution that enables you to power your Raspberry Pi with a battery and includes features such as an integrated real-time clock and on-board charging circuitry.
Frequently Asked Questions (FAQs):
Q: Can a Raspberry Pi be powered with a battery?
A: While USB port powering is the preferred option, it is possible to use batteries to power a Raspberry Pi. However, it is important to note that not all batteries are suitable, as we don’t have 5V batteries. Commonly used supplies are four AA batteries (over 6V fully charged), a 9V battery, or two 3.7 Lithium Ion Batteries (7.4V). It is important to avoid using any of these options, as they will fry your Raspberry Pi.
Q: How do I power a Raspberry Pi 4 with batteries?
A: To power up your Raspberry Pi, insert all but one of the batteries into the box and connect everything. When you’re ready, add the final battery and watch the status lights as the Pi boots.
Q: Can I power a Raspberry Pi with a 9V battery?
A: Yes, you can. While a 9V battery may seem like a good option, it is not recommended to power your Raspberry Pi with a small battery. The high power requirements of the Pi make it unsuitable for powering from a small 9V battery or even a set of AAA batteries. In practice, it is best to use a battery with a higher voltage than 5V, such as a 9V battery, and use a voltage regulator to drop the voltage to 5V.
Q: Can I power a Raspberry Pi from a 12V battery?
A: Yes, you can power a Raspberry Pi directly from a 12 volt battery using a 5V UBEC regulator.
Q: How long can a Raspberry Pi run on batteries?
A: The run time of a Raspberry Pi on batteries depends on the size of the battery pack. A smaller pack can power a Raspberry Pi model B, with an Edimax wifi dongle, idling for about 3.5 hours. On the other hand, a larger pack can last for nearly 9 hours at idle.
Q: Can a Raspberry Pi work with a power bank?
A: Yes, a Raspberry Pi can work with a power bank, as long as the power bank has an output voltage of 5V. While most USB power banks are capable of powering a Raspberry Pi, not all power banks are suitable. It is recommended to use a large power bank, such as a 50 Ah power bank, to ensure a longer run time of at least 24 hours.
