CONFIRMED in the filings, with caveats on the specs: the batteries for the Galaxy S27 Pro and Galaxy S27 Ultra have passed certification from Safety Korea, South Korea’s product safety agency. The listings name models EB-BS957CBY (S27 Pro) and EB-BS958DBY (S27 Ultra), under certification numbers YU10899-26034 and YU10899-26036, manufactured by Zhuhai CosMX Power in China.
The key point is to separate what certification proves from what is still a leak. The photos published from the Safety Korea database do not make the capacities legible. The capacity figures cited in the press come from an earlier leak and China’s 3C certification, not from reading those images directly.
Leaked capacities
According to those reports, the S27 Pro battery would have a rated capacity of 5,087 mAh and the S27 Ultra’s would be 5,534 mAh. In Samsung’s marketing, those figures usually become typical capacities of about 5,200 mAh and 5,700 mAh respectively — although at least one outlet cites 5,800 mAh as a possible nominal figure for the Ultra. So the direction is upward, but the final marketing number is not confirmed.
If 5,700 mAh holds for the Ultra, it would be roughly 14% more than the 5,000 mAh the Galaxy S26 Ultra kept across several generations. For the Pro, the jump over the S26+ would be about 6%. Reports also credit both models with 60 W wired and 25 W wireless charging, the same wired level cited for the S26 Ultra.
Also rumor, not an announcement: Samsung is said to have tested a 7,000 mAh prototype and chosen a smaller cell to preserve a slim design and the S Pen slot. The company has not announced pricing, availability or a launch date for the S27 line; reports point to the usual January-to-February window, but that is also officially unconfirmed.
In short: the certification is real and a concrete sign that the S27 Pro and Ultra line is being prepared, but capacities, charging and timing remain leak territory until Samsung speaks.
What to watch next
The next verifiable step is a Samsung statement: official typical capacity, charging, pricing and date. Until then, certification is evidence of preparation, not a final spec sheet — and any battery figure presented as definitive before that should be read as a leak.
Image credit: Safety Korea, via SamMobile.
Sources: SamMobile, Notebookcheck and GSMArena.
Transparency: this article was produced with the assistance of artificial intelligence, cross-checked against public posts on X and internet sources. Check the original sources to confirm details before acting on them.
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