One UI 9 rollout triggers battery concerns on older Samsung phones
Samsung has started to push the One UI 9 skin, built on Android 17, to legacy devices such as the Samsung Galaxy S24 Ultra and the newer Samsung Galaxy S25 series. While the update brings a refreshed interface and new features, a growing number of owners are reporting a sharp decline in battery endurance.
First reports highlight dramatic drain
One user on Phone Arena described watching the battery level fall from full to ninety‑five percent in just over five hours, even though the screen was active for only three hours and fifteen minutes. Similar anecdotes mention the phone needing to be charged three to four times a day after the upgrade.
Why the battery may be suffering
One UI 9 introduces a range of visual enhancements, background services and new AI‑driven widgets. During the first few days after a major system refresh, these components can consume extra power while they index apps, rebuild caches and calibrate system sensors. In many cases the extra draw subsides once the device finishes its background tasks.
However, some users of the Samsung Galaxy S24 Ultra and Samsung Galaxy S25 have observed persistent drain even after a week of normal use. The exact cause has not been confirmed by Samsung, and the company has not issued an official statement linking One UI 9 to a widespread battery defect.
What you can do if you notice a drop
First, try a simple restart. This can clear temporary processes that might be hogging power. Next, open the battery settings and review the list of apps that are using the most energy. Disable or restrict background activity for any app that seems unusually demanding.
If the problem continues, back up your data to a cloud service or a computer, then perform a factory reset. A clean installation often resolves hidden software conflicts that arise after a major update.
When to expect normal performance to return
It is common for a fresh system update to temporarily affect battery life while the operating system optimises itself. Most users report that the battery stabilises after a few days of regular use, especially if they keep the phone plugged in overnight during the optimisation period.
Related hardware news
For readers interested in the broader Samsung ecosystem, the brand‑new Galaxy Watch Ultra 2 has just been released. Our in‑depth review explores its health tracking features, battery longevity and how it integrates with One UI 9 on compatible smartphones.
In summary, while the One UI 9 update brings many visual and functional upgrades to the Samsung Galaxy S24 Ultra and Samsung Galaxy S25, a subset of users are experiencing notable battery life reductions. Monitoring app usage, restarting the device, and, if necessary, resetting to factory settings are practical steps to mitigate the issue until Samsung provides an official fix or a targeted software patch.