Galaxy S27 Ultra May Deliver Samsung’s First Major Battery Leap in Years

Samsung may be preparing one of its biggest battery upgrades in years for the Galaxy S27 Ultra. New leaks suggest the company is making progress with silicon-carbon battery technology, which could help solve a long-standing weakness in its flagship smartphones.

For several generations, Samsung has continued to use traditional battery designs, while several Chinese smartphone brands have already moved to silicon-carbon cells.

The main benefit of silicon-carbon batteries is higher energy density. This allows manufacturers to fit larger battery capacities into the same physical space without making devices thicker.

Samsung’s current Galaxy S26 Ultra still uses a 5,000 mAh battery, showing little change compared to recent models over the years.

If adopted, silicon-carbon technology could allow Samsung to increase battery size while keeping the phone slim.

According to leaked information reportedly based on Samsung SDI documents shared by the Schrodingerintel blog, the company has been testing silicon-carbon batteries ranging from 12,000 mAh to 20,000 mAh.

One of the more notable designs is a dual-cell setup labeled SDI-DC12K-SiC-V2. This battery combines a 6,800 mAh cell measuring around 4.7mm thick with a 5,200 mAh cell measuring around 3.2mm thick.

Reports suggest the 6,800 mAh cell, or a similar version, could realistically fit inside the Galaxy S27 Ultra without making the device excessively thick.

While the capacity gains look promising, durability appears to be the main obstacle.

The reported 20,000 mAh prototype managed around 960 charge cycles before failure. That falls short of the roughly 1,500 cycles typically expected for commercial products.

This may explain why Samsung has not yet introduced the technology in the Galaxy S26 lineup.

Leaked details claim Samsung engineers are now focused on improving separator materials, battery stacking methods, and battery management systems.

These changes are aimed at increasing lifespan and making the technology ready for consumer devices.

Samsung has previously acknowledged that it lags behind rivals in battery technology. That admission, combined with the latest leaks, suggests the company is working to close the gap.

If Samsung resolves the durability issues in time, the Galaxy S27 Ultra could become the first major Galaxy flagship to deliver a significant battery leap in years.