Anker PowerCore 10,000 mAh Quick Charger
Perhaps the best all around price/size portable charger is the Anker 10,000 mAh QC 3.0 battery for only $29.99. It offers nearly double that of the TYLT for half the cost. There are hundreds of cheap brands all over Amazon, so it's essential to get a portable charger from a reputable company that actually lives up to the battery rating. Many claim to be 10,000 mAh, but barely charge my device twice.
Anker is one of the best, and have high quality battery cells that will last, and actually hold a steady charge. The 10,000 mAh works as advertized and this pack features Quick Charge 3.0 technology, and works with older 2.0 devices too. It's basically one of the smallest, fastest, best chargers on the market. And my go-to charger. It only has one port, but that's fine. It also comes with a case.