Galaxy S27 Ultra silicon carbon upgrade is all but confirmed

This isn’t the first time rumors about the Galaxy S27 series and their battery upgrades have surfaced. Samsung has been admittedly behind the Chinese competition in delivering larger capacity batteries for its smartphones, but that will most likely change with the Galaxy S27 Ultra. The phone has once again been tipped to come with a silicon-carbon battery.

The information comes from the Schrodingerintel blog that sites Samsung’s internal SDI documents supposedly showing 12,000 mAh, 18,000 mAh, and 20,000 mAh Si-C cell testing. It states that Samsung has been testing these cells under designations SDI-DC12K-SiC-V2 and SDI-TC18K-SiC. The screenshot shows a 12,000 mAh setup with a 6,800 mAh cell at 4.7 mm and a 5,200 mAh cell at 3.2 mm thickness. This setup would be too chunky for a flagship phone as the stack thickness goes up to about 9.3 mm. However, a smaller battery – yet still plenty more than the standard 5,000 mAh – can theoretically still fit into the typical flagship form factor. It should be noted that these numbers are claimed to be from Samsung's internal testing and there is no proof of it as such.

That being said, the problem Samsung is currently dealing with is longevity. This particular setup failed at 960 charge cycles, which is well short of the commercial target of 1,500 cycles. The post claims that this was the reason why Samsung decided not to include the silicon-carbon upgrade in the Galaxy S26 series.

With tests running in full force, the author of the post believes that Samsung will surely deliver a silicon-carbon backed Galaxy S27 Ultra next year. They also point out that Samsung itself admitted that it is behind on battery tech which it wouldn’t have done if there wasn’t a plan behind it.

This follows the leak from late February that claimed a Samsung phone with a silicon carbon battery could be unveiled soon. At the time, it was believed to be a Galaxy S26 Edge before the Galaxy S27 lineup. Whether Samsung brings silicon-carbon to its phones this year, only time will tell, but it’s now looking even more likely that the Galaxy S27 Ultra will pack the much-anticipated upgrade.