Decided to book power bank along with a couple other items on my way to airport as I forgot to bring my own. They allow you to book just 6 hours before you arrival is a major lifesaver.
Used it a couple time for my trip to Asia and now I cannot travel without using them. It allows me to travel with the minimal of packing.
I love how I can now rent many of the heavy, bulky items that I only use a couple times during my trip, its just plain easier than bringing your own.