After Z Fold 8, Galaxy S27 May Get Silicon-Carbon Batteries

Samsung just put silicon-carbon batteries into a phone for the first time, and rumors  suggest the Galaxy S27 series won’t wait long to get the same tech. According to reports, Samsung is now running application tests on silicon-carbon batteries for the S27 lineup, following the technology’s debut in the Galaxy Z Fold 8 series.

Treat this one as directionally credible but still fluid. Multiple outlets are converging on the same testing claim, yet the specifics which models get it, and how much bigger the batteries actually end up keep shifting between reports, which is normal for a battery decision Samsung hasn’t locked down internally either.

The comparison point that matters is the Z Fold 8 Ultra, which shipped with a 5,000mAh silicon carbon battery, while the Z Fold 8 gets 4,800mAh and the Z Flip 8 comes in at 4,300mAh. For the S27 series, one Korean tipster reports Samsung testing silicon-carbon batteries with a possible 10% capacity bump over the Galaxy S26 series, with the base S27 possibly missing out entirely if Samsung restricts the tech to the Pro model and up over cost concerns. A separate, more recent report adds an important asterisk: the S27 versions may only contain a small amount of silicon while still being classified as standard lithium-ion, which could put the Ultra around 5,600 to 5,700mAh rather than a dramatic leap.

That’s a meaningfully smaller jump than what Chinese rivals are already shipping; the Oppo Find X9 Pro sits at 7,500mAh and the OnePlus 15 at 7,300mAh. Samsung’s caution here isn’t new; the company has moved slowly on battery chemistry since the Note 7 recall, and when directly asked about S27 plans, a Samsung SDI executive gave a deliberately noncommittal answer tying any rollout to whether it improves the actual customer experience rather than confirming a timeline.

None of this is official yet, and Samsung hasn’t confirmed which S27 models get the upgrade, if any. But the pattern is clear enough: Samsung is finally moving on silicon-carbon, just not at the scale its competitors have already normalized. If you’re waiting on the S27 for a genuine multi-day battery, the early signs point to a modest gain not the eye-popping capacity jump the “silicon-carbon” name might suggest.