WITH people juggling multiple digital devices that constantly need charging, backpack manufacturers have sensed a market opportunity. Some new backpacks are specifically designed not only to protect our smartphones, tablets, laptops, headphones and game players, but also to recharge them and track their whereabouts.

For those who need power as well as protection, Tylt’s $170 Energi Plus Backpack includes a 10,400 mAh battery, which can charge three devices simultaneously. Though it can hold up to a 15.5-inch laptop, it can’t charge one. The battery is intended for smartphones and tablets only.

The battery takes about seven hours to charge; once it’s 50 percent done it can begin to charge devices. There’s enough power to fully charge an iPhone 6 more than five times. If not used, the battery will retain its charge for around one year. Pass-throughs embedded in the bag allow charging cables to be secured and then routed through to most pockets.

Image Tylt’s Energi Plus Backpack includes a battery that can charge three devices simultaneously.

The bag is attractively designed, constructed of heavy artificial material, including an exterior pocket for a water bottle, a hardened one for glasses, and others for small business items. Numerous USB cables are included, as well as an older-style Apple 30-pin connector. The company says it’s working through its inventory before it will switch to a Lightning connector, like those used for the newest Apple mobile devices.