Energizer – yes, the battery company – has teased its upcoming smartphone, the P18K Pop. In addition to features like a pop-up selfie camera and a three-camera setup on the back, its main draw is an absolutely massive 18,000 mAh battery that adds more than a little heft to the handset.

By comparison, the battery in Apple’s flagship iPhone XS is a mere 2,658 mAh.

Of course, size alone doesn’t dictate overall battery life, which is why Apple never directly shares these numbers in its marketing. Battery life is highly contingent on the power requirements of other components; fast processors and high-res displays have their cost! The iPhone XS has much better specs than the Energizer Pop, and Apple is pretty good at power efficiency, so it’s hard to make a direct comparison.

But let’s give it a go anyway.

Apple says the iPhone XS offers 20 hours talk time or 12 hours of internet use. In other words: daily charging is usually necessary. Energizer doesn’t specify the number of hours it can survive, but 18,000 mAh is a lot more capacity than 2,658 mAh. Do the math and you’ll see the P18K Pop could offer somewhere in the region of five and a half full days on a call or just over three full days browsing the internet.

The drawback to all that battery life? Energizer’s beast of a smartphone clocks in at 18mm thick at its thinnest point. That makes it a minimum of 2.5x the thickness of the 7.7mm iPhone XS, with a curved back making it even chunkier in the middle. This is not a device you’d want to start a fight with. Even with all that space, there’s no room to hide a camera pop-out or cram in a headphone jack. The P18K Pop is all battery, baby.

We can barely even tell which one is the iPhone… (image credit: Mat Smith/Engadget)

This particular design is perhaps a step too far for most people (even ignoring that you’d have to switch to Android and accept lower specs) but the striking chunkiness of the P18K Pop is clearly a marketing exercise to get people pining for larger batteries. Though its long battery life and reasonable price tag ($600) may suit people who frequently go camping in the wilderness, we’d imagine the frame is just too bulky for most people.

That said, it did get us wishing Apple would compromise just a little in its quest for thinness – would you accept an extra couple mm thickness for an iPhone that lasted, say, two full days without charge?