Recently, details about the batteries for the upcoming Samsung Galaxy S27 Ultra and the speculated Galaxy S27 Pro have surfaced in South Korea's Safety Korea certification database. The battery models in question are EB-BS958DBY (for the S27 Ultra, model number SM-S958) and EB-BS957CBY (for the S27 Pro, model number SM-S957), both produced by the Zhuhai CosMX Jinwan factory in China. The S27 Ultra's battery boasts a rated capacity of 5,534 mAh and a typical capacity of around 5,700 mAh. Meanwhile, the S27 Pro's battery has a rated capacity of 5,087 mAh and a typical capacity of approximately 5,200 mAh. Notably, both batteries offer a larger capacity compared to their predecessors, with the S27 Ultra's battery seeing a roughly 14% increase over the 5,000 mAh battery found in the previous generation's S26 Ultra. According to reports, Samsung may utilize silicon-carbon anode technology to enhance battery capacity while maintaining a slim device profile. Furthermore, both models are expected to support 60W wired charging. It's important to note that these batteries are currently in the pre-mass-production phase, and Samsung has yet to confirm the final specifications. Additionally, the official existence of the S27 Pro model remains unverified.