@AnnieCActually I have no own experience, but I already tried to find the right numbers. To use USB, HDMI on a Raspberry Pi 4 you 2.5A minimum. For powering the original Pi LCD you can connect it to on off the Pis USB Ports, but that will reduce the brightness to 60%. To get full brightness you to connect it to a separate source. So the best solution will be something that has 2 USB connectors with min 2.5A output and 10000mAh capacityI found this board but I'm sure there are other USB packs available https://www.makerfocus.com/products/raspberry-pi-expansion-board-ups-pack-standard-power-supply?variant=32881868570701Maybe this helps you with your decision@rpimag