"Don't leave home without it" is a credit card advertising slogan that might as well apply to your laptop charger.

But come next year, you won't think twice about heading out for several hours with laptop in tow but without the computer's charger.

That’s because major manufacturers, including Asus, HP, and Lenovo, are about to roll out always-connected PCs that promise to deliver 20 hours or more of battery life. These always-connected laptops will all use an efficient Qualcomm Snapdragon processor similar to the kind used in Android smartphones.

More on Computers

“The main trend for 2018 is going to be these Qualcomm always-on, always-connected PCs,” says Jackson Somes, a market analyst at the Gap Intelligence research firm. “The real proposition for these devices is going to be battery life,” Somes says. “HP is saying 20 hours with their detachable model. That’s going to be their huge selling point.”

Asus claims even better performance, saying its new laptop will run for 22 hours between charges. 

If these always-connected laptops do achieve their claimed battery life, they would represent a dramatic improvement over other laptops CR has tested. Some of these models deliver just four to seven hours of battery life.

Even some of the longest-lasting models, including the recently released Dell XPS 13 and HP Spectre x360, hover around the 16-hour mark.

Consumer Reports will test the always-connected laptops once they are available for retail sale.

The promised battery life could let you use an always-connected laptop more like an LTE-enabled tablet: When setting up to work  at the local café, for example, you won’t have to jockey for a seat next to an electrical outlet.

And you won't have to connect to a WiFi network, either, since  always-connected laptops will also be able to connect to the internet wherever there’s a 4G LTE wireless signal.

That could be a big benefit when it comes to security. The always- connected laptops will be connected to a cellular LTE network, making your private information, including email and social media passwords, safer from any hacker lurking nearby. You can ether your laptop to your smartphone, but using 4G LTE promises to be more convenient.

(Note: Whenever you're on public WiFi, use a VPN, or virtual private network. It will route your online traffic through an encrypted connection, boosting security.)

Right now, the biggest question for always-connected laptops is cost. Prices for the computers haven't been released, and we also don’t know what it will cost to connect your laptop to a cellular network. 

Adding devices to a cellular contract is “a paradigm that people have wrestled with before,” says Rhoda Alexander, director of tablets and PCs at the research firm IHS Markit. “Depending on the [cellular provider], you may pay a fee to just put it on there to start with, and then a monthly fee, and then data charges.”

It’s also possible that these always-connected laptops could have the cost of wireless access baked into the up-front price of the device, the way Amazon includes wireless access with select models of its Kindle e-readers.

We hope to get answers to these questions at the upcoming CES, the annual technology trade show.