My Samsung Galaxy S24 went from lasting a full day on a single charge to dying by 2pm — and the only thing that changed was the One UI 7 update that installed automatically overnight. I didn't download any new apps. I didn't change how I use my phone. The battery just started draining at roughly double the rate it had the day before.
After running a detailed battery diagnostic and going through every setting that changed in the One UI 7 update, I found the specific process responsible. It's not the obvious suspects people blame — screen brightness, always-on display, or 5G. It's a background process called "Device Health Services" that One UI 7 re-enabled and reconfigured during the update, combined with a change to how Galaxy AI features handle background indexing.
Here's the exact cause and the exact fix.
What One UI 7 Changed That's Killing Your Battery
One UI 7 introduced two changes that interact badly on Galaxy S24 hardware specifically:
Change 1 — Device Health Services re-enabled and set to "Enhanced" mode One UI 7 reset Device Health Services to run in Enhanced mode, which performs continuous real-time monitoring of app performance, thermal output, and memory usage. On Galaxy S24, this process runs at a higher CPU frequency than Samsung intended — a known optimization miscalculation in One UI 7.0 and 7.1 that Samsung has acknowledged in developer forums but hasn't patched in a general update yet.
In Enhanced mode, Device Health Services consumes between 8% and 15% of your battery per day on its own — even when your phone is sitting idle on a desk.
Change 2 — Galaxy AI background indexing set to "Always On" One UI 7 enabled Galaxy AI features by default, including a background indexing process that continuously scans your photos, messages, and files to enable AI-powered search and suggestions. On Galaxy S24 (non-Plus and non-Ultra), this process runs on the main Snapdragon 8 Gen 3 cores rather than the efficiency cores — burning significantly more power than it should for what is essentially a background housekeeping task.
Together, these two processes running simultaneously can account for 20% to 30% of your daily battery drain — before you've even touched your phone.
The Exact Fix — Three Settings, Executed in This Specific Order
Order matters here. Changing these settings out of sequence can cause Device Health Services to re-enable itself during the next scheduled optimization cycle.
Step 1 — Change Device Health Services from Enhanced to Standard
Go to Settings > Battery > More battery settings > Device Health Services > tap "Mode" > select "Standard" instead of "Enhanced."
Standard mode still monitors app performance and battery health but runs on a less aggressive cycle — checking every 30 minutes rather than continuously. This alone reduces Device Health Services' battery consumption from 8-15% per day down to approximately 1-2%.
Do not disable Device Health Services entirely. Disabling it can cause issues with Samsung's warranty diagnostic system and occasionally triggers false low-battery warnings.
Step 2 — Restrict Galaxy AI background indexing to Wi-Fi only and charging only
Go to Settings > Advanced features > Galaxy AI > AI background tasks > change from "Always" to "Wi-Fi and charging only."
This restricts the continuous file indexing process to run only when your phone is plugged in and connected to Wi-Fi — meaning it still runs and keeps your AI features updated, but it no longer runs on battery power throughout the day.
Step 3 — Clear the Device Health Services cache to force it to restart in Standard mode
This step is critical and most guides miss it. If you skip this step, Device Health Services continues running its existing Enhanced mode process in memory even after you change the setting — and it won't switch to Standard mode until the next full restart cycle, which could be days later if your phone's adaptive restart schedule pushes it out.
Go to Settings > Apps > tap the three-dot menu in the top right > "Show system apps" > search for "Device Health Services" > Storage > Clear Cache.
After clearing the cache, restart your phone manually. Device Health Services will restart fresh in Standard mode rather than continuing its Enhanced mode session.
How to Confirm the Fix Worked
After the restart, let your phone sit idle and screen-off for exactly 30 minutes. Then go to Settings > Battery > Battery usage > change the time range to "Last hour."
Device Health Services should now appear at 1% or less in the last hour. If it's still showing 5% or higher, the cache clear didn't fully reset it — repeat Step 3, but this time clear both Cache and Data (not just cache). Clearing data resets Device Health Services to factory defaults, which guarantees it restarts in the correct mode.
Galaxy AI background tasks should not appear in the last-hour battery usage at all if you're not charging — if they do appear, go back to Step 2 and confirm the setting saved correctly.
Why Turning Off 5G Doesn't Solve This
The most common advice for Galaxy S24 battery drain is to switch from 5G to LTE. I tried this. It made a difference of about 4% per day — noticeable but not the root cause of the severe drain that One UI 7 introduced.
The Device Health Services and Galaxy AI indexing issues together account for 20-30% of daily drain. 5G accounts for roughly 4-8% on most networks. Fixing the 5G issue while leaving the Device Health Services issue untouched is like fixing a small leak while ignoring the burst pipe — you're solving the smaller problem and missing the larger one.
Fix the two One UI 7-specific issues first. If you still want to reduce 5G battery impact afterward, go to Settings > Connections > Mobile networks > Network mode > select "LTE/3G/2G (auto connect)" instead of 5G. But fix the root cause first.
Pro Tip: Check Battery Usage by "Last 24 Hours" Immediately After Any Major System Update
Every time Samsung pushes a One UI update, the first thing I now do is go to Settings > Battery > Battery usage > set the time range to "Last 24 hours" — and look at what's consuming more than 5% of battery without me actively using it.
Background processes that One UI updates re-enable or reconfigure almost always show up here within the first 24 hours. The pattern is consistent: a process you've never seen before suddenly appearing at 8%, 12%, or 15% of daily usage is the fingerprint of an update that changed a background setting you had previously optimized.
Catching it within the first 24 hours means you can identify the specific process and address it directly — rather than spending days suspecting apps, screens, or connectivity settings that aren't the actual cause.
After the One UI 7 update, Device Health Services showed at 14% in my first-24-hours battery report. Without that check, I would have spent days trying random fixes. With it, I had the exact culprit identified within five minutes of looking.
Last updated: July 2026. Steps are specific to Samsung Galaxy S24 running One UI 7.0 and 7.1. Samsung may address the Device Health Services optimization issue in a future One UI patch — check Settings > Software update for the latest available version before applying these manual fixes.
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