‘Tis the season for gadgets.

One of the most useful electronics offered this holiday season is the Jackery, an external battery that allows you to charge your smartphone and tablet on the fly. Imagine, up to 220 hours of extra operating time. That’s a little over nine days.

You’ll never get stuck with an dark iPad even on the longest flight — or if you lose power at home after a storm.

Frequent travelers say Jackery is as handy as a pocket on a shirt. And the smallest Jackery, about the size of a tube of lipstick, slides easily into a pocket — or a Christmas stocking.

The folks at Jackery sent me a Jackery Giant to try out, a cool orange model, which accommodates two devices and is still small, lightweight and portable. It measures 4.3 inches by 3.1 inches and weighs a scant 10.4 ounces. Doesn’t take up much room in the glove compartment.

With a full charge, the Jackery has enough power to stand by for six months between uses. No worries about running out of juice between blackouts. You can recharge the battery at least 500 times.

There’s a full line of Jackery products so you can find just the right fit for your needs. Prices on Amazon.com start at $29.95.