Powering a Raspberry Pi 4 reliably
Why the wrong charger causes crashes, and which one to use.
Start with the recommended supply
Raspberry Pi recommends a suitable USB-C supply for the Pi 4. Its documentation lists 5V at 3A. Use the correct voltage and a quality lead, and allow for connected accessories rather than relying on an arbitrary phone charger.
Check portable power carefully
A power bank’s headline wattage does not guarantee the required output at 5V. Read the rating for the actual port and test the Pi under load with its accessories connected. Some power banks turn off when demand is low.
Keep the installation cool
Use a case suited to the board and leave ventilation clear. Check the instructions for fitting heatsinks and connecting any fan. Additional cooling and accessories change the overall power budget.
Shut down cleanly
Save work and shut down the operating system before removing power. For a portable project, make shutdown part of the routine. Keep a spare system image so a damaged card does not leave the whole setup unusable.
Further reading: Raspberry Pi getting started.