While competitors like OnePlus and Honor have been experimenting with adding bigger silicon-carbon batteries to their phones, South Korean tech giant Samsung seems to be remaining conservative. Even its Galaxy S25 Ultra and S25 Edge sport lithium-ion cells, prompting many to ask Samsung when it will finally stop playing it safe.
Although we still don’t know when the tech giant will stop playing it safe, we do know that it is working towards it. And well, if this report is correct, what Samsung is cooking is far larger than what anyone might have expected.
According to an AndroidHeadlines report, quoting a source on X, Samsung SDI, the tech giant’s battery manufacturing arm, is working on a dual-stack silicon-carbon battery with a massive 20,000mAh capacity.
There’s a longevity hurdle
The South Korean tech giant is experimenting with stacking two silicon-carbon batteries on top of each other, resulting in a slightly thicker, albeit a much higher capacity cell.
According to the report, the dual-stack Samsung SDI is testing contains one 12,000mAh cell and a second 8,000mAh cell, resulting in a combined battery capacity of 20,000mAh.
Before you get too excited though, Samsung tested out the dual-stack for over one year with roughly 960 cycles and observed that the 8,000mAh cell swelled up from 4mm to 7.2mm. This, of course, is a longevity failure. During that time, the battery offered 27 hours of screen-on-use per charge.
If Samsung is successful in fixing the swelling issue over the coming tests, not only will we see behemoth 20,000mAh batteries making their way to the South Korean tech giant’s own devices, but also smartphones from other brands that either already rely on Samsung for batteries, or might in the future.
27 hours of screen time might not be a pipe dream after all. How long does your current phone last on a single charge? Let us know in the comments below!
