Buying the best smartphone power pack - MrMobile explains

[WindowsCentral.com]

Proclaiming one external battery charger to be the "best power pack" for all people is a daunting challenge ? and it misses the point.
The reality is that, as with smartphones, different power banks work well for different users. But I've collected between twenty and thirty external battery pack accessories in my time reviewing technology, and I've found that the secret to making the search a little less daunting is to focus on three key areas: safety, capacity, and speed.

Full story from the WindowsCentral blog...