What is the maximum amperage of a mobile battery for charging or powering the camera?
The maximum amperage of a mobile battery for charging or powering the camera is 1.5A (0.5-1.5A).
Fast charging is possible when a USB PD (USB Power Delivery) device is connected. For more details, refer to Which Sony cameras support USB PD (USB Power Delivery)? article.
Note: If you are using a USB PD (USB Power Delivery) device, make sure it supports an output of at least 18W (9V/2A).