The Samsung Galaxy S27 Ultra battery was supposed to be a Beast. Early leaks teased 6,000 mAh and even numbers close to 7,000 mAh. Now a fresh report drags those dreams back down to earth. Samsung’s next flagship may only inch past the 5,000 mAh mark it has clung to for far too long.
Here is the good news first. We are finally moving on from that aging cell. The bad news? We are not moving nearly fast enough.
Galaxy S27 Ultra Battery: What the Latest Leak Claims
A new tip comes from the X account @phonefuturist. According to that source, Samsung is testing two different cells for the phone. One measures 5,600 mAh. The other reaches 5,800 mAh. Either number would beat the current Ultra. So there is reason to smile.
But not everyone buys it. Veteran leaker Ice Universe quickly poured cold water on the hype. In their words, no reliable evidence points to a 5,500 mAh battery just yet. They also expect Samsung to stay at or below that 5,500 mAh line. If they are right, a 5,800 mAh cell looks like wishful thinking.
Take every figure here with a healthy grain of salt. The phone is still roughly half a year away. Leaks this early tend to shift, and they often disagree.
How the Galaxy S27 Ultra battery rumors stack up
| Source | Claimed capacity | How much to trust it |
|---|---|---|
| Earlier leaks | 6,000–7,000 mAh | Now looking unlikely |
| @phonefuturist | 5,600 or 5,800 mAh | Unverified test units |
| Ice Universe | 5,500 mAh or less | Highly credible leaker |
Why the 5,000 mAh Era Had to End
Here is the frustrating part. The Ultra line has shipped a 5,000 mAh cell for seven straight years. It started with the Galaxy S20 Ultra back in 2020. It carried on, unchanged, all the way to the Galaxy S26 Ultra.
Clever software and efficient chips have papered over the gap. The Snapdragon 8 Elite Gen 5 for Galaxy squeezes out real savings. Even so, the results speak plainly. In our real-world tests, the S26 Ultra lasts about two hours less than the iPhone 17 Pro Max. That is a wide margin at this price.
So the message is simple. Samsung has to grow this number, whether it likes the idea or not.
Galaxy Ultra battery capacity, year by year
| Model | Year | Battery capacity |
|---|---|---|
| Galaxy S20 Ultra | 2020 | 5,000 mAh |
| Galaxy S21 Ultra | 2021 | 5,000 mAh |
| Galaxy S22 Ultra | 2022 | 5,000 mAh |
| Galaxy S23 Ultra | 2023 | 5,000 mAh |
| Galaxy S24 Ultra | 2024 | 5,000 mAh |
| Galaxy S25 Ultra | 2025 | 5,000 mAh |
| Galaxy S26 Ultra | 2026 | 5,000 mAh |
| Galaxy S27 Ultra | 2027* | 5,600–5,800 mAh (rumored) |
*Expected launch window based on Samsung’s usual yearly cadence.
How Big Will the Galaxy S27 Ultra Battery Really Be?
The pessimists expected something tiny, like a 5,200 mAh cell. I would rather stay a touch more hopeful than that.
A roughly 600 mAh bump is still not enough for me. In an ideal world, the next Ultra would pack a 7,000 mAh silicon-carbon cell. That density exists today, and rivals already use it. Yet we have to be realistic about who we are dealing with.
This is Samsung. The company rarely leaps far ahead in a single year. It prefers small, safe steps. So Ice Universe may well be right. We might not see an Ultra flagship cross the 5,500 mAh line this time.
Wireless Charging: Still No Qi2 Magnets?
Battery talk aside, charging matters too. The Galaxy S26 Ultra bumped wireless charging up to 25W. Older Galaxy phones topped out at a slower 15W. That was a welcome step forward.
There is a catch, though. The S26 Ultra skipped built-in magnets. So it does not support Qi2 or MagSafe-style magnetic charging on its own. Your only workaround is a case with magnets baked in.
That gap annoys plenty of buyers. iPhones have offered MagSafe for years. Even the Pixel 10 series added Qi2 magnetic charging in 2025. For now, no solid leak confirms Qi2 magnets on the S27 Ultra. Still, hope lingers that Samsung will get there eventually.
In Other Samsung News: One UI 9.0 Draws Closer
Samsung is also busy prepping One UI 9.0. The stable release is expected later this month. To get ready, the company keeps updating its apps and modules.
Several Good Lock modules already got the treatment. That list covers ClockFace, LockStar, MultiStar, NavStar, and RegiStar. Now the Display Assistant module joins them. Version 9.0.08 is live on the Galaxy Store as a 7.92MB download. It simply adds compatibility with One UI 9.0, which is based on Android 17. Do not expect new features or fixes from this one.
One UI 9.0 will debut on the Galaxy Z Flip 8, Galaxy Z Fold 8, and Galaxy Z Fold 8 Ultra. Samsung is expected to announce all three on July 22, 2026. Sales should begin on August 5, 2026. Existing flagships like the Galaxy S26 series should start receiving the update around the same window.
Key Takeaways at a Glance
- The Galaxy S27 Ultra battery is now rumored at 5,600–5,800 mAh, far below the earlier 7,000 mAh dream.
- Trusted leaker Ice Universe doubts anything above 5,500 mAh, so keep expectations grounded.
- The Ultra line has been stuck at 5,000 mAh for seven years, from the S20 Ultra to the S26 Ultra.
- Real tests show the S26 Ultra trailing the iPhone 17 Pro Max by about two hours.
- Wireless charging sits at 25W, but there is still no native Qi2 or MagSafe magnet support.
- One UI 9.0 lands later this month, launching first on Samsung’s new foldables.
What This All Means for You
If you are eyeing the Galaxy S27 Ultra battery for a huge endurance leap, temper that excitement. A modest gain looks likely, not a revolution. For heavy users, that may still disappoint.
My honest advice is simple. Wait for confirmed specs before you commit. If battery life is your top priority, compare the final numbers against the iPhone 17 Pro Max first. Samsung is finally moving past 5,000 mAh, and that alone is progress. Just do not expect the company to sprint when it clearly prefers to walk.
Find more helpful Galaxy S27 Ultra guides below.
- Samsung Galaxy S27 Ultra – Sorry Apple… Samsung Copied It
- Samsung Galaxy S27 Appears in IMEI Database First
- Galaxy S27 Ultra upgrades loom, but S27 Pro shines
- Galaxy S27 Ultra Camera Bar Shift Is About Qi2 Magnets