My smartphone (Nexus 6) has a large battery (3220 mAh) and some days when I’m using phone for calling, video, and research I’m out of juice about dinner time. Fortunately for me I always carry a quick charger. I can get 50% of my charge back in less than 30 minutes. I highly recommend one for you.
Today, Amazon is offering a great coupon on the Kmashi 20000 mAh Quick charger. You can pick it up for $20 with this coupon.