The Samsung Galaxy S26 Ultra's battery and charging features have been widely discussed and leaked through multiple credible sources up to late 2025. The battery capacity in the S26 Ultra is confirmed to be essentially the same as the one in its predecessor, the Galaxy S25 Ultra, continuing Samsung's trend since the Galaxy S20 Ultra from 2020. The official certified battery, with model number EB-BS948ABY/E, has a rated capacity of 4855 mAh, which is marketed by Samsung approximately as a 5000 mAh battery. Thus, there is no real increase in the mAh capacity for the S26 Ultra as compared to the S25 Ultra or its predecessors.
Samsung has maintained this battery size for six years across its Ultra flagship models despite competitors moving ahead with notably larger batteries. For instance, phones like the OnePlus 13 come with a 6000 mAh battery, Oppo Find X8 Ultra has a 6100 mAh cell, and even mid-range models like the Moto G86 Power possess batteries above 6700 mAh in a slimmer design. This long-held 5000 mAh battery limits Samsung's ability to match battery longevity offered by competitors with larger capacities.
The company's reluctance to increase battery size stems partly from safety considerations after the Note 7 battery incident and a preference for software and AI-driven battery management improvements rather than hardware changes. Samsung is focusing on optimizing battery usage and longevity over simply increasing battery capacity. There are reports that Samsung aims to improve energy density in the battery cells, potentially making the physical battery smaller or better managed thermally, which could free up internal space and improve heat dissipation during use or charging.
Charging technology in the S26 Ultra is expected to see a significant upgrade compared to previous Samsung Ultra models. For many years, Samsung capped wired charging speeds for its Ultra phones at 45W, but the S26 Ultra is rumored to support 60W to 65W fast charging. This represents the first notable jump in charging speed for Samsung's premium flagship line since the launch of the S22 Ultra. The fast charging capability should be able to recharge the battery to around 80% from zero in about 30 minutes, which is a marked convenience improvement for users.
While 60-65W charging is slower than some competing brands that now offer charging speeds of 100W or more, Samsung seems to be prioritizing sustained charging speeds with better thermal management instead of brief intense charging bursts followed by rapid throttling. This means in real-world usage, the S26 Ultra could maintain higher charging speeds longer before stepping down power to protect battery health. Samsung's proprietary algorithms for charging optimization are well regarded for balancing speed and battery preservation.
In addition to faster wired charging, the S26 Ultra is also expected to support enhanced wireless charging standards. The phone is rumored to adopt Qi2 wireless charging at up to 25W power, which is currently the fastest wireless charging speed available on Samsung smartphones. This is an improvement over earlier models, making wireless charging more practical for users who prefer cable-free charging options.
Battery life improvements for the S26 Ultra may not come from the battery size per se but rather from the use of more advanced processors and improved software optimizations. The S26 Ultra is likely to ship with Qualcomm's Snapdragon 8 Elite 2 chip, built on an enhanced 3nm process by TSMC, promising better energy efficiency and performance. Samsung is also testing the Exynos 2600 chip, based on a 2nm manufacturing process, which could further improve power efficiency if used. These chipsets' advanced fabrication processes typically reduce power consumption and heat output, which directly benefits battery life in real-world scenarios.
In summary:
- The Samsung Galaxy S26 Ultra will continue with a battery capacity around 4855mAh rated, marketed as 5000mAh, identical to the Galaxy S25 Ultra and previous Ultra models since 2020.
- Despite the stagnant battery size, Samsung is reportedly improving battery energy density and thermal management.
- Wired fast charging steps up to 60W-65W, cutting charging time significantly compared to previous 45W limits.
- Wireless charging will be enhanced to 25W with support for Qi2 standard.
- The phone will employ highly efficient processors (Snapdragon 8 Elite 2 or possibly Exynos 2600) that promise better battery life through lower power consumption.
- Samsung prioritizes sustained charging speeds and battery longevity over raw peak charging numbers, offering a more balanced approach to fast charging.
- The charging improvements make for a better charging experience but do not fully catch up to some competitors offering larger batteries and ultra-fast 100W+ charging.