Recently we've been asked again if you can run a Macbook Pro from a USB-A battery. The kind that powers Phones.
Here's what we said:
You can only use batteries that have high power output, like 16-20vdc and about 4amps.
It is impossible to Power the Magsafe Macbooks from USB.
It's like asking a motorcycle engine to pull a Semi-truck.
In technical terms, USB is only 5v, and max at 3a. That's only about 15w. Your Macbook starts at 60w (Macbook Pro 85w). There is no way to up-convert 15w to 60w. It's like asking for magic.