If you built one of the lightest laptops in the world, but critics complained about poor battery life, what would you do?

Would you build a laptop with a bigger, longer-lasting battery? Or would you pretend the same tiny laptop now has more battery life than any other laptop ever made?

LG just did both. At CES 2017, LG announced that its new Gram laptops can last an unprecedented 24 hours on a charge. The moment I read that, I knew there must be some funny business going on.

The truth: LG measured that 24 hours with a decade-old benchmark.

A terrible benchmark, too -- a benchmark so bad at measuring laptop battery life that Computerworld wrote a scathing story about it eight years ago. It's a benchmark that assumes you'll be barely using your laptop at all, without Wi-Fi, and with the screen set to very low brightness.

But apparently, LG can get away with saying "24 hours" as long as it uses a picture of that benchmark, "MobileMark 2007," next to each pseudo-lie.

Enlarge Image LG

Enlarge Image LG

Thing is, LG's laptop probably will last quite a bit longer than the previous version. The company says it used carbon nanotube technology to create a 60Wh battery -- nearly double the capacity of the previous 34.6Wh pack, and bigger than the one in Apple's new 13-inch MacBook Pro -- without increasing the laptop's incredibly light weight of about 2.1 pounds (about 0.9 kilograms).

They're a little bit thicker (0.61 inches for the 13-inch model, compared to 0.5 inches for last year's 14-incher), but it sounds like a feat.

And LG does say that when it used a newer benchmark (MobileMark 14), the company still got as many as 17 hours on a charge -- which sounds pretty great. But we'll still need to test it. Don't know about you, but I have a tough time trusting companies that use decade-old benchmarks.

Aside from the battery life, the new 13-inch, 14-inch and 15-inch LG Gram laptops feature:

Intel's new Core i3, i5 and i7 Kaby Lake processors

Up to 512GB of solid-state storage and up to 16GB of RAM (each has two RAM slots, one user-accessible)

1,920 by 1,080-pixel resolution IPS touchscreen displays with extremely small bezels

Two USB 3.0 ports and a full-size HDMI video jack

A MicroSD (not full-size SD) card slot

A USB-C port that can charge the laptop, and/or output data and video (or Thunderbolt 3, in the 15-inch version, according to Microsoft)

802.11ac Wi-Fi

HD webcams in the center of the hinge, so they point up your nose (also see: Dell XPS 13)

Fingerprint readers for one-touch Windows login (according to Microsoft)

An extra USB 2.0 port in the 15-inch version

Fast charging (LG claims 3 hours of battery life for a 20 minute charge)

Enlarge Image LG

LG hasn't yet confirmed when or where the new Gram laptops might arrive outside its native South Korea, or for how much, but a Korean press release suggests they'll start at 1,420,000 won (roughly $1,200, £965 or AU$1,630).

It also mentions a second set of ultra-light Gram laptops which will come with a smaller 34Wh battery.