Samsung’s Galaxy S27 Ultra and the rumored Galaxy S27 Pro have had their batteries spotted in South Korea’s Safety Korea certification database, giving us the first photos of the units. Notebookcheck found the listings under model numbers EB-BS958DBY for the Ultra and EB-BS957CBY for the Pro, and both batteries are reportedly made by Zhuhai CosMX Power’s subsidiary in China. The capacities aren’t legible in the photos, so the figures below come from earlier regulatory filings.
| Model | Battery model | Rated capacity | Expected typical capacity | Previous model |
| Galaxy S27 Ultra | EB-BS958DBY | 5,534mAh | About 5,700mAh | Galaxy S26 Ultra: 5,000mAh |
| Galaxy S27 Pro | EB-BS957CBY | 5,087mAh | About 5,200mAh | Galaxy S26+: 4,900mAh |
The rated capacities first leaked in July and were later certified by China’s 3C. If the typical figures hold, the S27 Ultra would gain 700mAh, a 14% increase over the S26 Ultra, ending years of Samsung sticking with 5,000mAh on its Ultra phones. The S27 Pro’s expected 5,200mAh would beat the S26+’s 4,900mAh and would also edge past the S26 Ultra’s battery. The same 3C filing lists 60W wired charging for both phones, unchanged from the S26 Ultra.
The certified units are pre-production samples, so the final retail batteries may differ. The listings also don’t reveal the battery chemistry. Some leaks suggest Samsung could adopt higher-density silicon-carbon cells to add capacity without making the phones noticeably thicker, which would fit with the Galaxy S27 Ultra’s tipped thicker camera bump. Separately, Samsung reportedly tested a 7,000mAh prototype for the Ultra but settled on a smaller cell to keep the S Pen.
The Galaxy S27 series is expected in early 2027, potentially in January or February. Samsung hasn’t announced the Galaxy S27 Pro, the Ultra’s battery specs or a launch date. Our Galaxy S27 Ultra master page collects everything else known about the phone so far.
M Adnan Akram is the founder and lead writer at Phoonomo, covering mobile technology with a primary focus on Apple and the broader smartphone industry, alongside emerging developments in AI. He follows product launches, spec leaks, and industry trends closely to keep readers informed with timely updates.
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