Phones have been getting bigger for years, but rarely do they get fatter. We may want a big display for video and internet, but we still want a slim phone that's easy to carry.

Energizer, the same company that makes batteries, didn't get that memo. At MWC 2019 in Barcelona, it showed off a new phone called the Power Max P18K Pop that's an eye-popping 18mm (almost three quarters of an inch) thick. For comparison's sake, that's thicker than more than two Samsung Galaxy S10s. Energizer doesn't actually build the phone -- French company Avenir Telecom has that job instead.

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But there's a good reason for the bulk: The Power Max P18K Pop has a ginormous 18,000-mAh battery. Yes, you read that correctly. That's even more generous than last year's P16K Pro, which Energizer said would last up to five days during normal use and up to 40 days on standby.

The P18K Pop is supposed to fully charge in eight hours and supports fast charging.

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That Energizer battery powers a 6.2-inch display and a Mediatek Helio P70 processor. A cool feature is the 2-megapixel dual selfie camera that pops up out of the phone's body. Other highlights include 6GB of RAM, 128GB of storage and a microSD card slot. There's also a rear-facing triple camera (12-megapixel, 5-megapixels and 2-megapixel), Android Pie and a dual SIM slot.

Energizer also showed a prototype for a dual-screen device called the Power Max P8100S. Its promised features would include a 48-megapixel camera, a front-facing 24-megapixel camera, 256GB of storage, 8GB of RAM, a 10,000-mAh battery and a Snapdragon 855 processor.

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