A new leak indicates that Samsung could finally be breaking its long-held trend regarding battery capacity for the Galaxy S27 Ultra, possibly surpassing the battery capacity expected for Apple's iPhone 18 Pro Max. However, while most of its rivals have switched to silicon-carbon batteries, the new leak suggests that Samsung will continue using the lithium-ion battery technology.
According to tipster @phonefuturist, Samsung is testing 5,600 mAh and 5,800 mAh cells from its in-house battery unit, Samsung SDI, after previously settling on a smaller 5,200 mAh solution. If the testing holds up, the Galaxy S27 Ultra could ship with a battery exceeding 5,500 mAh, which would mark Samsung's first meaningful battery increase in the Ultra lineup since the Galaxy S20 Ultra launched back in 2020.
Notably, Samsung seems to be accomplishing this transition without resorting to using silicon-carbon batteries, which many Chinese phone manufacturers have opted to use for their superior energy capacity. In any case, it seems like Samsung is intent on improving its current lithium-ion technology.
Apple's next flagship is also expected to grow its battery this cycle. Leaked reports suggest the eSIM-only model available in the United States is going to feature a 5,425 mAh cell, whereas the version with the physical SIM card in other regions will offer a smaller 5,235 mAh one. The latter would be the largest ever seen in any iPhone from Apple, although Samsung's upcoming 5,500 mAh+ battery will surpass it in size.
| Device | Battery Capacity (Leaked/Current) |
|---|---|
| Samsung Galaxy S27 Ultra | 5,500 mAh+ (testing up to 5,800 mAh) |
| Apple iPhone 18 Pro Max (eSIM) | 5,425 mAh (Expected) |
| Apple iPhone 18 Pro Max (Physical SIM) | 5,235 mAh (Expected) |
| Samsung Galaxy S26 Ultra (Current) | 5,000 mAh |
| Apple iPhone 17 Pro Max (eSIM) | 5,088 mAh |
Also Read: Samsung Galaxy Z Fold 8 vs Foldable iPhone Ultra Early Comparison: Camera, Features, Design & More
Samsung has traditionally packed larger batteries than Apple's Pro Max models, though the iPhone 17 Pro Max's eSIM variant briefly broke that pattern. Despite this, mAh values may not always directly correlate to actual performance time, given iPhones use one operating system while Galaxy phones use another, with drastically different power efficiencies.
In this regard, other flagship models from China, such as the OnePlus 15 and Oppo Find X9 Pro, come with battery capacities that range from 7,300 to 7,500 mAh, leaving the competition from Samsung and Apple in the dust. Naturally, as any pre-release information is concerned, all these numbers are only speculative until confirmed by Samsung and Apple.