How good is the battery life of the Asus ROG Zephyrus S GX502? Is the GX502 good for work?

• Typical keyboard layout and fast trackpad makes for easy writing
• GPU switch means that the dedicated graphics isn’t always on, which saves power
• Clever design allows heat to escape
• Battery life is good by gaming laptop standards (but still not brilliant)

Whether you’re using the Asus ROG Zephyrus S GX502 for work or play, the battery is going to take a beating. Gaming laptops are notoriously demanding and power-hungry, and the GX502 is no exception.

At the launch event, Asus told me that buyers can expect up to six hours of power out of the GX502. 

If you’re working, by which I mean writing, updating spreadsheets, and doing basic photo correction on GIMP or PS Elements, you can expect to wring between 3-5 hours out of this, depending on how diligent you are. When gaming, you won’t be able to approach the 3 hour mark without the ‘battery low’ warning bugging you.

I ran a series of benchmarks to round this out, and they produced results roughly in line with my real-world observations. In all the battery tests I ran, the screen’s brightness was set at 150 nits to ensure uniformity.  

Running the ‘Work’ battery drain simulation on Futuremark’s PC Mark 8 suite, I got two hours, and 35 minutes – this was out of the box with Nvidia’s Optimus technology running the show. When I turned dedicated graphics on and ran the same test, this dipped to one hour, 37 minutes.

One hour of Netflix with the volume set to 50% would see a full battery drop by about 20%. Rounding out the battery drain test, I looped one two minute 4K video sample until the battery failed, and the GX502 faded to black after five hours and five minutes.

These results are fairly typical for gaming laptops, but can’t compete with the likes of lifestyle laptops like the MacBook Pro 2018, Microsoft Surface Laptop 2, or even Asus’s own ZenBook 15.

The good news is that with the supplied charger, you can get the GX502 filled back up in around 90 to 120 minutes. While nobody is seriously going to play games without the mains power, if you’re facing down a series of interminable strategy meetings in the office, you may want to have the charger to hand, lest power levels start to dip while you’re midway through your PowerPoint presentation.

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