Samsung Testing 12,000mAh, 18,000mAh Multi‑Cell Batteries, Leak Reveals

Samsung is reportedly testing a new generation of ultra‑high‑capacity silicon‑carbon batteries that could dramatically boost how long future smartphones last on a single charge. Internal Samsung SDI test documents leaked by tipster Schrödinger (@phonefuturist) on X suggest the company is working on 12,000mAh and 18,000mAh battery designs using stacked dual‑cell and triple‑cell configurations instead of the single‑cell layouts used in most phones today.

One 12,000mAh prototype combines two cells rated at 6,800mAh and 5,200mAh with the total battery thickness reportedly kept under around 9.3mm hinting that such a pack could fit into larger smartphones or foldables without making them uncomfortably bulky. The 18,000mAh design is more complex using three cells rated at 6,699mAh, 6,000mAh, and 5,257mAh; Samsung is said to be targeting a thickness of about 12.3mm although early samples are around 12.8mm due to additional thermal‑management layers.

The documents also mention a 20,000mAh prototype that failed Samsung’s internal tests after roughly 960 charge cycles falling short of the company’s reported long‑term durability goals. Samsung is believed to be aiming for around 1,500 charge cycles for commercial products which would translate to several years of daily charging for typical users. If brought to market the 12,000mAh silicon‑carbon battery could in theory deliver about 20-25 hours of continuous screen‑on time on a smartphone connected to data and Wi‑Fi far beyond current flagship norms.

These batteries are still in the testing phase and there is no confirmation that they will appear in upcoming Galaxy phones, tablets, or other devices. However, the leak indicates Samsung is aggressively exploring higher‑density battery technologies as phones become more powerful and power‑hungry potentially paving the way for future devices that can last well over a day of intensive use on a single charge.

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