TL;DR: Having discovered that packing an 18,000mAh battery into a handset doesn't make it appealing when the device looks like a literal brick, Energizer and phone-maker Avenir have dropped the capacity ratings to a still impressive 7,000mAh and 5,000mAh and switched to a design that won't double as a hammer.
PCMag writes that The Energizer Ultimate U680S was at Mobile World Congress, though it seems the company isn't ready to show off any images yet. It reportedly forgoes the monstrously chunky build of the Power Max P18K Pop on show at the 2019 event for something relatively slim---under 10mm thick---despite featuring a 7,000mAh battery. For comparison, the Galaxy S21 Ultra is 8.89mm thick and has a 5,000mAh battery.
The Power Max P18K Pop, you may remember, had an 18,000mAh battery, more than the 16,000mAh Power Max P16K Pro Energizer had on display the previous year. The company claimed it could continuously watch videos for two days, listen to 100 hours of music, talk for 90 hours, and provide 50 days of standby time. And at 18mm thick, be used as a deadly weapon.
The P18K Pop. Energizer's latest big-battery phone is at least 8mm slimmer
The P18K Pop Indiegogo campaign finished with $15,005 from just 11 backers---slightly short of the $1.2 million funding goal---proving that people don't care about 50 days of standby time when a phone needs a wheelbarrow to be portable.
Energizer and Avenir Telecom seem to have learned their lesson with The Energizer Ultimate U680S. "You can take your phone and go through more than a day... and it really fits in your pocket, I swear," said Loic Schiano, Avenir's spokesman.
The U680S is definitely aimed at the budget end of the market: it's priced at $139.99 and uses a Unisoc processor. It also doesn't appear to have the band support and certifications to work in the US.
The Hard Case G5, courtesy of PCMag
One Energizer phone that could be coming to the US is the Hard Case G5. The rugged Android 11 device features a 5,000mAh battery, sub-6GHz 5G, a MediaTek Dimensity 720 chipset, and is IP69 rated for a "high pressure and temperature water jet."