Being faced with a near-dead phone and no way to recharge can be a little panic-inducing. A portable power bank can help keep that feeling at bay, giving your devices a quick charge no matter how far you stray from an outlet. Toss a small one in your pack for a partial refill on a smartphone, or grab a higher-capacity battery to take to the diner where you’ll park it for the day to work on your laptop. We’ve tested dozens of battery packs for this guide over the past year to come up with our top... Read this story