I rarely travel without an external battery pack and charging cable at hand, just in case my cellphone runs out of juice.

Sometimes, all my phone needs is a little power pick-me-up. That's when I grab my wallet, pull my little LifeCard from its slot, and charge. What you have here is a sleek, brushed-stainless-steel rechargeable power bank the size of a credit card and about three credit cards thick. A built-in micro-USB or lightning cable (the card comes in two models) pulls out from one corner, then slides back into its corner nook.

The LifeCard has an integrated mini-USB port for recharging via an included (not built-in) 7-inch-long flat-ribbon USB cable. Four pinholes in the card display LEDs that signal when the card is fully charged.

LifeCard's size comes with a trade-off. Fully charged, the 5-volt, 1-amp battery can provide a 65 percent to 80 percent recharge for iPhones predating plus sizes and similar Android models. Bigger phones will get 30 percent to 40 percent.

The LifeCard can power up a phone while recharging, but yes, I still tote a bigger powerhouse for big-time needs.

LifeCard Power Bank for Android (micro USB cable) or iOS (Lightning cable) is about $50 at www.amazon.com.