The other things is that the weather here is unpredictable so I need to be able to carry a small umbrella outside of the bag (so if it gets wet, i can stick it in an outside pocket) and the bag needs to be able to keep inside items dry when raining). (theverge.com)
The charging function is activated by pressing a power button on the outside of the bag. (canadianbusiness.com)
There are two smaller compartments on the outside of the bag. (businessinsider.com)