Samsung may be preparing one of the biggest battery upgrades in the history of its flagship Galaxy Ultra series, even though the company is reportedly not yet ready to adopt silicon-carbon battery technology.

According to information shared on Telegram by the account @phonefuturist, Samsung is still carefully evaluating whether to switch to silicon-carbon batteries for the Galaxy S27 Ultra. However, the company is said to be testing significantly larger battery capacities while continuing to use conventional lithium-ion technology.

Samsung may increase battery capacity without silicon-carbon technology

According to the leak, cost remains the biggest reason Samsung has not adopted silicon-carbon batteries.

The report claims equipping one million Galaxy S27 Ultra devices with silicon-carbon batteries would increase production costs by an estimated US$22 million to US$28 million. By comparison, conventional lithium-ion batteries would reportedly cost between US$12 million and US$15 million for the same production volume.

That difference could add tens of millions of dollars to manufacturing costs at a time when smartphone makers are already facing rising component prices.

The report also points to continued pressure from global DRAM supply constraints, which have pushed up memory prices and forced manufacturers to manage costs more carefully to protect profit margins and remain competitive.

As a result, Samsung is reportedly reluctant to introduce technologies that could significantly increase production expenses unless the benefits clearly justify the additional cost.

Galaxy S27 Ultra could finally surpass 5,000mAh

Although Samsung may delay the move to silicon-carbon batteries, the company is reportedly testing larger conventional battery cells for the Galaxy S27 Ultra.

A post on X claims Samsung is evaluating batteries with capacities ranging from 5,600mAh to 5,800mAh.

If testing proceeds successfully, the final commercial device could feature a battery with a minimum capacity of around 5,500mAh.

If accurate, the Galaxy S27 Ultra would become the first Galaxy Ultra smartphone to exceed the 5,000mAh threshold since the Galaxy S20 Ultra introduced that capacity.

While the rumored battery would still be smaller than those found in some flagship smartphones from Chinese manufacturers, many of which already use silicon-carbon batteries with capacities between 6,000mAh and more than 7,000mAh, battery capacity alone does not determine real-world endurance.

Power efficiency depends on a combination of processor design, software optimization and intelligent power management.

Software optimization could play a bigger role

The report suggests Samsung could narrow the battery life gap through improvements to software efficiency.

Apple has followed a similar strategy for years. Although iPhones generally have smaller batteries than many Android competitors, the Pro Max models consistently rank among the longest-lasting smartphones because of the close integration between Apple's processors and iOS.

Industry observers expect Samsung to continue improving power management through future versions of One UI, reducing energy consumption during everyday tasks such as web browsing, video streaming and background app activity.

Better optimization could allow the Galaxy S27 Ultra to compete more effectively on battery life without relying solely on an extremely large battery.

Battery could become a key selling point

Another rumor suggests the standard Galaxy S27 Pro may retain a 5,000mAh battery, creating a clearer distinction between Samsung's Pro and Ultra models.

If the Ultra receives a battery of around 5,500mAh, it could become one of the model's biggest hardware upgrades and a major selling point in Samsung's premium smartphone lineup.

The timing may also be significant as smartphone manufacturers continue to face higher component costs, particularly for memory, which could place additional pressure on pricing and consumer demand.

As with all pre-release information, Samsung has not officially confirmed any battery specifications or hardware features for the Galaxy S27 series.

Hai Phong