With the iPhone Duo launch now out of the way, it's time to start looking forward to some of the phones headed our way in the near future — into 2027 and beyond. The next big release we're expecting is the Samsung Galaxy S27, and the latest leak may have revealed what batteries to expect from two of the four upcoming models.
That's right, four models, because rumor has it that Samsung will be releasing a new Galaxy S27 Pro. Presumably this is a device that will sit between the Plus and the Ultra models, though we'll have to wait and see just what Samsung has planned. This new battery leak covers the mysterious Pro and the flagship Galaxy S27 Ultra.
Two batteries have just shown up on the Safety Korea database, alongside photos, featuring the model numbers EB-BS957CBY and EB-BS958DBY. This lines up with the SM-S957 and SM-S958 model numbers tied to the S27 Pro and Ultra, suggesting these are the batteries we'll see in next year's high-end Galaxy phones.
We can't quite see the capacities, but past leaks suggest that we'll see 5,534 mAh and 5,087 mAh batteries, with typical capacities of 5,700 mAh and 5,200 mAh, respectively. If those figures are accurate, it means this is the first time the Ultra model has had a battery capacity upgrade since the release of the Galaxy S20 Ultra almost seven years ago. Charging is said to be 60W on both, which is the same as the Galaxy S26 Ultra.
This is a long time coming
For those that don't remember, the Galaxy S20 Ultra was the first of Samsung's modern Ultra phones, and it came with a 5,000 mAh battery — up from 4,100 mAh on the Galaxy S10 Plus. This 700 mAh upgrade effectively means that the S27 Ultra is shaping up for an extra 100 mAh for every year Samsung ignored the calls for higher battery capacity.
This 700 mAh upgrade effectively means that the S27 Ultra is shaping up for an extra 100 mAh for every year Samsung ignored the calls for higher battery capacity.
Presumably this increase in capacity will be aided by Samsung's recent push into silicon carbon battery technology. As we saw with the Galaxy Z Fold 8, the different battery chemistry allows phone makers to improve battery density — packing more power into the same amount of space.
The batteries pictured don't look particularly big, which lends some support to that theory. Plus, the Z Fold 8 managed to adopt the new batteries without issue, and it makes little sense to avoid rolling silicon carbon out to other premium Samsung phones.
The Galaxy S27 series is expected to launch in early 2027, with rumors suggesting Samsung may pivot back to a January launch window. In the meantime we'll be seeing a lot more rumors about what all four phones can do, so stay tuned to Tom's Guide to hear all the best news and rumors as we hear about them.