Power Bank
A great pocketable pack TravelCard Charger With integrated cables to charge itself and a device, the TravelCard is the most convenient pack we tested—but it has a low capacity considering its high price. $30 from TravelCard If all you need is to get a few extra hours out of your phone in a pinch, the TravelCard Charger is the credit-card-sized choice to keep with you all the time. The TravelCard has a built-in Micro-USB or Lightning-connector plug to charge your phone, plus a built-in USB cable with a full-size USB Type-A plug to recharge the TravelCard itself. The combination gives you power wherever you are without your having to carry any cables. It packs only enough power to add 30 to 50 percent of a charge to the battery of a large smartphone, but even that can feel life-saving when you’re faced with low-battery warnings. Unfortunately, you’ll pay a big premium for the convenience and small size: Though this model is often on sale, it’s the most expen...