Some good powerpack batteries include the Amazon Basics Portable Power Bank, the EasyAcc Ultra Slim Power Bank, the Anker PowerCore 15600 and the RAVPower Xtreme Portable Charger, according to TheWireCutter.com. These battery packs range from small devices for emergencies to large devices that can charge multiple devices.
The Amazon Basics Portable Power Bank offers 2,000 milliamp hours, or mAh. The device comes with a micro USB cable. It is about the size of a credit card and around four times the width. The device offers more power than most of its similar competitors for a lower price as of 2015.
The RAVPower Xtreme Portable Charger offers 26,800 mAh of power, enough to charge a cellphone several times. The devices has three ports to charge multiple devices simultaneously. This device weighs 21 ounces, and is 6.8 inches long, 3.2 inches wide and about 1 inch thick. If this powerpack is taken on a flight, then it must be left in carry-on luggage and not stored in checked luggage.