I ditched my laptop charger for a day of travel, work and gaming with Intel's new Core Ultra Series 3 chip and still had 18% battery life left when I got home

Gaming laptop battery life is, by and large, rubbish. Or rather, trying to use a gaming-capable machine for a full day of work without charging it is, err, rubbish. I've hauled many discrete GPU-equipped lappys into the office for a spot of real-world testing, and most of them are usually begging to be plugged into a wall socket by lunchtime.

Upon hearing Intel's battery life efficiency claims for its new, Panther Lake-based, Core Ultra Series 3 chips, I knew what needed to be done. Top up my Asus Zenbook Duo review sample overnight, take it on my round trip from my Southampton home to PC Gamer Towers in Bath (a roughly 126 mile jaunt), use it for a regular day, and record when it conks out.

It's a dGPU-less machine, which means all the graphics hardware is contained onboard the single Core Ultra X9 388H chip at its heart. Despite this, the built-in Arc B390 iGPU delivers some impressive gaming performance for its size, meaning that laptops powered by Intel's new mobile chips (the ones with chonky iGPUs, anyway) can now reasonably be called gaming laptops.

Intel says that Core Ultra Series 3 machines can boast up to 27-hour battery life, but my Asus sample is a bit different. It's got dual OLED displays for a start, which means my testing had to take into account the uniqueness of the particular design. I resolved myself to only use the extra screen for demonstration purposes and the odd photo shoot, to try and gain an indicative figure of what you might expect from a more regularly-formatted laptop.

Which, according to Asus, should give me a maximum battery figure of 18 hours+ under ideal conditions. Setting off on the train that morning, though, I wasn't too confident. I'd initially planned to leave the tiny USB-C charging brick at home, but a last minute panic meant I threw it in the bottom of my bag anyway. Call if a lack of faith, if you will.

I started out by checking my emails using the terrible on-train Wi-Fi, along with a news search for our regular coverage. This involves multiple tabs, browser windows, and the odd bit of YouTube watching. Arriving at the office around two hours later, I anxiously checked the battery indicator.

92%. A pretty good start for the Panther Lake lappy, although roughly what I expected. Brandishing the shiny new machine in front of my colleagues, it was then briefly handed around the group for some cooing and cawing. The dual screens were flipped open and fiddled with, and the magnetically-attached keyboard was enthusiastically pulled on and off—causing the OLED displays to power up and down in quick succession.

More doubts entered my mind. I still had a full eight-hour working day in front of me, and I was planning to finish off with some light gaming on the journey home. Could this power-efficient machine, even with a 99 Whr battery system, really run the distance?

As is the way when you get your head down at work, I soon forgot about my battery anxiety. I set to work typing up my performance testing piece, attending video meetings, and juggling multiple windows and tabs. While I wouldn't describe myself as a power user in the traditional sense (I'm not 3D modelling or spending all day in Photoshop, for example), my role involves a whole lot of multitasking—and the PTL chip cruised through every demand I asked of it with ease.

By lunchtime, after roughly four hours of near-constant usage, I was down to around 70%. My mood improved immensely at this point, as it was clear that the lappy's battery was relatively unbothered with my usual work routine. Merrily, I skipped into Bath for an overpriced sandwich.

However, my post-lunch afternoon was about to provide a more demanding test. Heading down to our studio, I used the Asus machine as a note provider for a chat with my hardware overlord, Dave, about the new Panther Lake chips, before capturing some B-roll footage and photos with our peerless video team.

Again, those dual OLEDs were booted into life, with the brightness boosted for an accurate capture. I thought about all the tech running inside my charger-denied sample.

Twin 1800p OLEDs, blazing away in front of me as the laptop rotated on a motorised plinth. 16 CPU cores, albeit with Low-Power Efficient versions taking the lead on battery power alone. Perhaps I should start closing some tabs and background apps to even the odds a little?

I resisted. This was a real-world test, and while the dual-screen design of this laptop skews the data a little, I was still curious as to the capabilities of the Asus machine itself.

Back to the office, and back to my review. More tabs, more multitasking, more heads-down typing. A glance out the window revealed darkness, which meant my journey back on the train was soon to begin. Finishing up my day, I slipped the laptop into my backpack with just over 40% battery remaining. Pretty good going, but the gaming test was yet to come.

The Arc B390 iGPU is a very capable little graphics cruncher, but I knew that booting up something truly demanding, like Cyberpunk 2077, would likely be a battery-draining mistake. There's no room for a mouse and keyboard setup in most seats on a British train, anyway, so I went for an old, trackpad-friendly favourite—Civilisation VI.

What do you mean there's a new one? I hadn't heard. Anyway, Civ's relatively undemanding needs were well-catered for by the Panther Lake chip, even at 1800p, and the battery life needle barely moved. No great surprise there. Norland was much the same. I began to wonder if my gaming testing was really representative.

Lightweight games are the sort of thing I usually play while travelling, but most iGPUs would cope without tanking the battery too hard.

So I booted up Hitman World of Assassination instead. Wandering around the streets of Marrakesh and making a nuisance of myself, I kept an eye on the battery indicator. At 1080p Medium settings, some rough maths revealed a loss of 5% battery life every 10 minutes.

Gulp. Still, I kept playing the bald-man-goes-wild simulator until my journey was over, snapped the lid of the Asus machine shut, and stuffed it into my bag for the walk home from the station. Returning to my digs, I opened the laptop with a heavy heart. Surely my 3D gaming excursions had left it with nothing but a blank screen and a desperate need for a top up?

Nope. I was left with 18% battery remaining. I could have kept playing Hitman for another half an hour, or easily got some more work done once I'd returned home without reaching for the charging plug.

For those of you with ultra-efficient, productivity-style laptops in your possession, the idea of all-day battery life is far from a new one. But from a gaming laptop, it's a rare sight. It's also an impressive indication of just how efficient Intel's new chips are when subjected to all the rigours one might throw at them over a long day, and how well the Core Ultra X9 388H handles its power management.

I could have realistically left the Asus machine's power brick at home, and not worried once about making it back with battery life to spare. And while we're not quite at the point where laptops are capable of delivering truly phenomenal gaming battery life, I think my testing is a pretty good indication that we're well on our way.

My usage adds up to around 11 hours total, give or take. And while that might not seem too impressive at first glance, the fact I had nearly 1/5th of the battery remaining after a full day, including nearly two hours of gaming time, has made me rethink what I expect from a gaming machine's portable potential.

Intel's Arc B390-equipped chips will rightly gain plenty of accolades for their iGPU gaming performance—but when it comes to legacy, it might be the battery life that cements their place in the hardware hall of fame.