Updated: April 20, 2026 | By The Editorial Team
If you recently updated your Galaxy S25, S25+, or S25 Ultra to the One UI 8.5 DZB9 build, you may have noticed reduced battery life or some lag when using the phone. While this update brings exciting Android 16 features and Ambient Design, many of us are dealing with significant battery idle drain and frame drops when swiping the Quick Panel.
These issues can increase heat generation and reduce how long your phone lasts between charges, which is why many users are looking for safe ways to reduce drain and improve responsiveness without a factory reset.
Why is this happening?
The DZB9 build is a late‑stage beta (or pre‑stable release) that still contains some unfinished or inefficient code related to the new animation and design changes, which can cause extra system load. Essentially, the new frosted glass effects are clashing with background system tasks, causing your S25 to work harder than it needs to.
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When the phone’s processor and GPU work harder, power consumption and heat can increase, which may shorten battery life and make the phone feel warmer during regular use.
Quick, Low‑Risk Fixes for One UI 8.5 DZB9
- Wipe Cache Partition: Boot into Recovery Mode and clear the cache. This can resolve many of the glitches and lag issues caused by leftover files from the previous One UI build.
- Disable Home Up (Good Lock): If you use Good Lock, turn off the Home Up module to reduce conflicts with the Quick Panel. Third‑party modules sometimes override default animations, which can cause temporary stutter until the module is updated for One UI 8.5.
- Limit Always On Display (AOD): Switch your AOD to Tap to Show so the screen stays off more often. This reduces background screen activity and can help lower idle battery drain while the phone is left idle.
Deep Dive: Why One UI 8.5 DZB9 Is Causing Extra Battery Drain
We’ve seen reports of Screen-On-Time (SOT) dropping from a solid 8 hours to a measly 4 hours. You might even feel your phone getting warm while scrolling through basic social media. Our testing shows two main culprits:
- Background Optimization: One UI 8.5 introduced AI Photo Assist and Storage Share. AI Photo Assist scans photos and videos to recognize objects and scenes, while Storage Share helps sync selected folders automatically. In DZB9, these features can run more frequently than usual, which increases background CPU usage and power consumption.
- Kernel Sleep‑Related Glitch: A known issue in this build can prevent the processor from entering a truly low‑power state when the screen is off, which may cause higher idle drain than expected. This is something Samsung typically fixes in later stable builds.
Actionable Solutions for One UI 8.5 DZB9
- Enable Deep Sleeping Apps: Go to Settings > Battery > Background usage limits. Add apps you don’t need notifications from to Deep Sleeping. This lets the system restrict background activity for those apps, which can reduce unnecessary power usage over time.
- Adaptive Battery Reset: Toggle Adaptive Battery off and then on again. This resets the model that learns your app‑usage patterns, which can help the phone adjust more accurately to how you actually use it after the update.
- Check System UI Usage: If System UI is using more than about 5–7% of your battery over a normal day, it may indicate that the status bar and Quick Panel are doing extra work. This can be a sign that the UI is under extra load, such as from animations or misbehaving apps.
| Metric | One UI 8.0 (Stable) | One UI 8.5 (Build DZB9) |
| Avg. SOT (Ultra) | 7.5 – 8.5 Hours | 4.0 – 5.5 Hours |
| Idle Drain (Overnight) | 2-3% | 8-12% |
| Performance Profile | Consistent | Occasional Thermal Throttling |
These figures are based on typical mixed‑usage patterns (social apps, browsing, video, and standby) and may vary by device model, network conditions, and installed apps. If your numbers are very different, your specific usage or background apps may be contributing to the drain.
Fixing Quick Panel Lag in One UI 8.5 DZB9
The Quick Panel may feel slightly slower during certain swipes, especially in the DZB9 build.
Samsung’s new non‑linear animation style in One UI 8.5 is visually smoother, but early builds like DZB9 may not handle all animations perfectly when interacting with other features such as the Task Changer. If you use Good Lock, modules like QuickStar may not yet be fully optimized for the new translucent layers and animations, which can temporarily increase lag or power usage until the module is updated.
Technical Fixes:
- Use Galaxy App Booster (Good Guardians): Download Good Guardians from the Galaxy Store and run App Booster. This can reoptimize app code for the new OS version, which may improve responsiveness and reduce glitches. This is optional and may help more on heavily customized setups.
- Animation Scales (Developer Options): Go to Developer Options and set Window animation scale, Transition animation scale, and Animator duration scale to 0.5x. This reduces the duration of visual transitions, which can make the UI feel slightly faster and may reduce momentary lag, but does not affect core performance or battery in most cases.
- Screen Zoom Adjustment: Some users report that very small screen zoom levels can cause minor alignment issues with the Quick Panel. If you notice this, switching back to Default or a more standard zoom level may help smooth out the layout.
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Advanced Troubleshooting for Power Users
If the steps above don’t work, we need to go deeper. These are the “gold standard” methods for power users.
1. Wiping the Cache Partition
This does not delete your personal data, such as photos, messages, or installed apps. It only clears temporary system and cache files from the previous build that may be conflicting with the new One UI 8.5 layout and animations, which can help reduce glitches and lag.
How-To: Turn off your S25. Connect it to a PC via USB. Hold Power + Volume Up until the recovery logo appears. Use volume keys to select “Wipe Cache Partition” and Power to confirm.
2. The “Repair Apps” Feature
Inside that same Recovery Menu, you’ll see an option called “Repair Apps.” This attempts to recheck and realign installed applications for the new build, which may help with some app crashes or stutters caused by update‑related mismatches. This is not a guarantee, but it can be a useful step if you notice apps behaving unexpectedly.
3. The Factory Reset Verdict
When could a factory reset be worth considering?
If your phone continues to feel unusually warm and shows persistent battery drain or lag for more than 48 hours after the update, and you’ve already tried the steps above, a clean install may help reset the system to a more stable state. This is a last‑resort option and always requires backing up your data first.
Important: A factory reset will erase all data from your phone, including apps, photos, and settings. Always back up important content to Samsung Cloud, Google Drive, or an external backup before starting this process.
Future Outlook
The good news is that Samsung is aware. Current roadmaps suggest the stable One UI 8.5 rollout will begin April 30, 2026, in South Korea, with a Global/US rollout around May 4, 2026.
Look out for builds CZDB or higher. These are expected to be more stable than DZB9 and include further optimizations for the Galaxy AI features.
Conclusion
The DZB9 build is clearly a transition phase. While the lag and drain are annoying, they are usually software-based and fixable with the steps we’ve outlined. Don’t lose hope in your S25 just yet!
Are you seeing different SOT numbers? Drop your model (S25, +, or Ultra) and your current battery percentage in the comments below to help our community track this bug!
Frequently Asked Questions:
Q 1: Why is my Galaxy S25 battery draining so fast after One UI 8.5 DZB9?
In the DZB9 build, new animations (like frosted glass and Ambient Design) and background features (such as AI Photo Assist and Storage Share) can run more frequently than usual, increasing CPU and GPU usage. Combined with a kernel‑sleep‑related glitch in this beta, this can cause higher idle drain and shorter Screen‑On‑Time on your Galaxy S25, S25+, or S25 Ultra.
Q 2: Does wiping the cache partition delete my photos or apps?
Well Wiping the cache partition only removes temporary system and app‑cache files from the previous One UI build. It does not delete personal data like photos, messages, apps, or settings. It’s a safe, low-risk step to try after a major update if you’re seeing lag or glitches.
Q 3: Will turning off Always On Display (AOD) extend my battery life?
Yes, in many cases. When AOD is set to “Always on,” the screen (or parts of it) stay active even when the phone is idle, which uses extra power. Switching AOD to “Tap to Show” keeps the screen off more often and can reduce idle battery drain, especially on builds like DZB9 where the display stack is under extra load.
Q 4: What does “Deep Sleeping Apps” do in One UI 8.5?
Deep Sleeping Apps restrict background activity for apps you don’t need to run all the time (like social apps or games). When an app is in deep sleep, it can’t run in the background as freely, which helps reduce unnecessary CPU usage and may lower battery drain over time. This feature is optional and works well for apps that don’t need constant notifications.
Q 5: Is toggling Adaptive Battery helpful after One UI 8.5?
Yes, in some cases. Adaptive Battery learns your app-usage patterns and limits background activity for apps you use less. After a major update like One UI 8.5 DZB9, toggling it off and on again can help the system relearn your habits and adjust background limits more accurately, which may improve battery life and responsiveness.
Q 6: When should I factory reset after One UI 8.5 DZB9?
A factory reset should only be considered if your Galaxy S25 continues to feel unusually warm, shows persistent battery drain, and still lags heavily more than 48 hours after the update—even after trying all the fixes above (cache‑wipe, AOD‑limit, background‑usage tweaks, Developer Options, and Repair Apps). Always back up your data before resetting, since this erases apps, photos, and settings.
Q 7: Will the stable One UI 8.5 build fix DZB9 battery issues?
Samsung’s roadmap suggests that stable builds (such as CZDB or higher) will replace DZB9 and include final optimizations for the Galaxy AI suite and background usage. These later versions usually fix known battery-drain and lag issues caused by earlier beta builds, so many users see improved battery life and smoother performance after the stable update drops.