This 28,000 mAh Energizer Phone Just Keeps Going, and Going - CNET

In a world where smartphone batteries hardly last more than a day, Avenir Telecom conjured up a device with a 28,000 mAh battery, which the company says can last for up to a week. The catch: It's a brick, clocking in at about three times the thickness of an iPhone 15. 

Avenir unveiled the phone at Mobile World Congress in Barcelona on Monday, calling it the Energizer Hard Case P28K -- it licenses the name from the battery manufacturer. The Hard Case P28K has three rear cameras (60, 20 and 2 megapixels), a 16-megapixel front camera, and can shoot 4K video. It sports an 6.78-inch, 1080p screen and an IP69 rating. It can reportedly be fast charged at up to 33 watts, and comes with a 36-watt charger. 

By comparison, the Samsung Galaxy S24, whose battery life we absolutely loved, has a 4,000 mAh battery. Plenty more goes into battery life than just pure amp-hours but promising this thing could last a week is not far-fetched, based purely on the numbers.

Read more: Best Phone to Buy for 2024

The tradeoff for ridiculous battery life is a relatively more primitive mobile experience, since the Hard Case P28K doesn't even have 5G. According to The Verge, the processor is a MediaTek MT6789, and the phone runs on Android 14. There's 8GB of RAM and 256GB of storage. And at 27.8 millimeters (1.1 inches) thick and 570 grams, it'll definitely weigh down your pockets (if it even fits).

The device will reportedly go on sale in October, for just under $300. Avenir told Android Authority the phone is geared toward countries without a regular power supply, and isn't slated for a US release. The company didn't immediately respond to a request for more information; our team on the ground in Barcelona is trying to get their hands on it right now.

There have been a host of other unique concepts and products at this year's MWC, including phones that can wrap around your wrist, a Barbie Flip Phone and the unveiling of the OnePlus Watch 2.