Samsung Galaxy S26 Ultra battery vs Galaxy S25 Ultra: What’s improved?

The Samsung Galaxy S26 Ultra and Galaxy S25 Ultra both have the same 5,000mAh battery^[1] capacity. The real difference is what the Galaxy S26 Ultra does with it: faster wired and wireless charging, better efficiency, and better heat management.

In other words, the battery is the same size, but the Galaxy S26 Ultra delivers a better real-world battery experience through charging speed and efficiency rather than a bigger cell.

The key battery and charging improvements on the Galaxy S26 Ultra:

Yes, both use the same 5,000mAh battery. But battery life is determined more by efficiency than by size. A phone’s real-world endurance comes down to how fast it recharges, how efficiently its processor draws power, and how well it manages heat. The Galaxy S26 Ultra improves on all three compared to the Galaxy S25 Ultra.

The Galaxy S26 Ultra charges faster over a cable than the Galaxy S25 Ultra. It supports up to 60W wired charging through Super Fast Charging 3.0^[4], compared with 45W through Super Fast Charging 2.0 on the Galaxy S25 Ultra. The increase to 60W means it can refill its battery more quickly when you have a compatible charger connected.

In practical terms, that is enough for a quick top-up before heading out. A short time on the charger gets the phone back to a comfortable level for the rest of the day.

The Galaxy S26 Ultra charges noticeably faster wirelessly than the Galaxy S25 Ultra. It supports up to 25W wireless charging through Super Fast Wireless Charging, compared with 15W on the Galaxy S25 Ultra. That is a meaningful step up, and it changes how useful wireless charging is in everyday situations.

At that speed, wireless charging becomes practical for quick top-ups during the day rather than just overnight charging.

The full 25W wireless speed needs a compatible charger, such as Samsung’s Galaxy Magnetic 25W Wireless Charger. Because the Galaxy S26 Ultra has no built-in magnets, a Qi2 magnetic case keeps the charger aligned.

The Galaxy S26 Ultra gets more out of every charge thanks to a more power-efficient processor. It is powered by the Snapdragon 8 Elite Gen 5 for Galaxy, which is built on a 3nm manufacturing process.

The 3nm process node means the transistors inside the chip are more tightly packed and require less power to switch states, so the processor can do more work for the same amount of energy it draws from the battery.

For everyday use, this efficiency means the Galaxy S26 Ultra can handle demanding tasks — gaming, video, navigation, and Galaxy AI^[5] processing — while making good use of the available battery. Even though the processor is significantly more capable than the previous generation, the efficiency of the 3nm process helps the phone maintain strong battery performance during typical daily use.

The Galaxy S26 Ultra holds its performance steady during demanding tasks thanks to improved heat management. It uses the largest vapour chamber Samsung has fitted to a Galaxy S Ultra device, with up to 21% better heat dissipation than the Galaxy S25 Ultra, keeping the processor in its efficient operating range during long gaming sessions, extended video recording, and heavy multitasking.

Because the Galaxy S26 Ultra and Galaxy S25 Ultra share the same 5,000mAh battery, the Galaxy S26 Ultra’s advantages come from how it uses and refills that battery.

Faster wired and wireless charging mean less time spent topping up. A more efficient 3nm processor means each charge is used more effectively. Improved thermal management means the phone holds its performance steady during demanding tasks.

The takeaway: the Galaxy S26 Ultra’s battery advantage is not capacity but charging speed and efficiency. It refills faster and uses each charge more effectively than the Galaxy S25 Ultra, which is what most people notice day to day.

^{[1] Typical value tested under third party laboratory conditions. Rated minimum capacity of the Galaxy S26 Ultra is 4,855mAh.}

^{[2] 60W charger sold separately.}

^{[3] 25W wireless charger sold separately.}

^{[4] Super Fast Charging (SFC) 3.0 requires a USB Power Delivery (PD) 3.1 (or higher) compatible device supporting Direct Charging.}

^{[5] Galaxy AI: Samsung account login is required for certain AI features.}