Galaxy S25 Ultra S24 Ultra battery drain issue returns after the July 2026 update. Phones run hot, charge slow, and die fast—here’s the WhatsApp fix owners are using.
Galaxy S25 Ultra S24 Ultra Battery Drain Issue: History Repeats and Owners Are Fed Up
Galaxy S25 Ultra S24 Ultra battery drain issue reports exploded again in late July 2026, and the pattern feels painfully familiar. Owners install what looks like a normal security update. A day later the phone that used to last until bedtime is gasping by lunch. The back gets warm while it sits on a desk. Charging crawls. Screen-on time barely moves, yet the percentage keeps falling.
If that sounds like your week, you are not alone. Posts on Reddit and Samsung’s own community forums describe the same story across both flagships. Samsung has not posted a clear public fix yet. Everyday users, however, have already zeroed in on a likely culprit and a workaround that restores normal life for many.
What Owners Are Actually Seeing
The complaints share a tight set of symptoms. One Galaxy S25 Ultra user watched daily battery use jump from roughly 80 percent to 143 percent after the July patch—even though they used the phone less. Idle drain of 5 to 7 percent per hour shows up in several threads. Another owner went from about 85 percent at midnight to nearly empty by midday with only two hours of screen time.
Heat arrives with the drain. Phones feel warmer than usual during light use or while locked. Some people also notice slower wired and wireless charging. When a device burns power as heat instead of storing it, charge times stretch.
On the S25 Ultra, affected firmware often ends in CZG3. Plenty of S24 Ultra owners report the identical behavior after their own July package. The problem is not limited to one generation or one region.
This Is Not the First Time
Cast your mind back to April 2026. The same two Ultra models got hit by severe battery drain and excess heat after a security update. Back then many fingers pointed at a Samsung security service running wild in the background. The company eventually gathered reports and the noise faded after later patches.
Now the July release has revived the headache. Same phones. Same sudden idle drain. Same warmth. Same slow charging for a slice of users. When a premium device that costs well over a thousand dollars keeps stumbling after routine updates, patience runs thin. People expect security patches to protect the phone, not quietly ruin the battery.
The WhatsApp Angle That Changed the Conversation
Community sleuthing moved fast. Several affected owners noticed that WhatsApp appeared stuck during its end-to-end encrypted backup. The app keeps trying to finish the job. The processor never fully sleeps. Power draws stay high. Heat builds. That loop matches the idle-drain pattern almost perfectly.
It also explains why some phones look fine in Safe Mode or after heavy app restrictions, then fall apart again once WhatsApp resumes its backup attempt. The July update itself may not be malicious. It may simply leave the messaging app in a broken state that never resolves on its own.
Not every drained Ultra will trace back to WhatsApp. Background loops from other apps or system services can create the same mess. Still, the encrypted-backup theory is the most consistent lead right now, and the fixes built around it are helping a clear majority of people who try them.
Want the exact steps that calmed dozens of hot, hungry Ultras? They are coming up next.
Try This WhatsApp Fix First
Before you wipe the phone or camp at a service center, work through the messaging app.
Open WhatsApp. Go to Settings, then Chats, then Chat backup. Look at the end-to-end encrypted backup section. If a backup appears stuck, in progress forever, or repeatedly failing, cancel it.
Many owners say the idle drain dropped the moment they cancelled the stuck process. Battery graphs returned to normal within hours.
If cancelling alone does not stick, take the fuller route some Reddit users needed:
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Turn off end-to-end encrypted backups.
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Let any regular backup finish cleanly, or skip it for now.
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Force-stop WhatsApp and clear its cache (not data) in system settings.
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Restart the phone.
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Open WhatsApp again and confirm no backup is spinning.
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Only after the phone stays cool and the battery holds, turn encrypted backups back on and run a fresh one on Wi-Fi overnight.
Yes, turning encryption off even briefly feels uncomfortable. Do it on a trusted network, finish the cycle quickly, and re-enable protection as soon as the backup completes. Leaving encrypted backups broken and looping is worse for both privacy and battery.
Extra Steps If the Drain Continues
Not cured yet? Layer on the classics that help after almost any messy Galaxy update.
Restart properly. Power all the way off, wait thirty seconds, then boot again.
Open Settings > Battery and study the last 24 hours. Anything that used power while you slept deserves a background restriction.
Update WhatsApp and every other high-use app from the Play Store and Galaxy Store.
Wipe the cache partition. Power off, hold Volume Up and Power until recovery appears, select Wipe cache partition, then reboot. Your photos and accounts stay safe.
Enable Adaptive Battery and, if you can spare a little speed, switch the performance profile to Light. Cooler phones last longer.
Test Safe Mode. If heat and drain vanish there, a third-party app is still misbehaving. Remove recent downloads until the culprit shows itself.
Switch to LTE for a day if your 5G signal is weak. A modem hunting for signal is a quiet battery killer.
Avoid gaming or long camera sessions while the phone is already warm or while it is charging. That mix pushes temperatures higher fast.
When You Should Contact Samsung
If the phone still loses big chunks of charge while idle after the WhatsApp fix and a cache wipe, stop tinkering and document everything. Screenshot the battery graph. Note the exact software version under Settings > About phone > Software information. Write down when you installed the July update and when symptoms began.
Take that package to Samsung Members support or an authorized service center. Under warranty you should not have to live with a flagship that turns into a space heater after a security patch. Keep your proof of purchase handy.
Skip the old “drain to zero three times” recalibration myths. Modern batteries do not work that way, and deep discharges only add stress.
Why Silence From Samsung Stings
Owners have already filed reports through official channels. Public acknowledgment has been thin to nonexistent at the time of writing. That gap is the most frustrating part of the whole saga.
When you spend flagship money you should not need a Reddit detective badge to keep your phone usable. Clear “we are aware and investigating” language costs little and buys a lot of goodwill. Temporary workarounds spread faster than official notes, which tells you the community is doing the support job the company has not finished yet.
Software teams need logs, device models, and reproduction steps before they ship a clean patch. That process takes time. In the meantime, people still have to get through workdays, maps, and messages without hunting for chargers every three hours.
Quick Checklist You Can Finish Tonight
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Cancel any stuck WhatsApp encrypted backup.
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Disable encrypted backups, clear WhatsApp cache, restart, then re-enable cleanly later.
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Check Battery usage and restrict greedy apps.
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Update all apps.
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Wipe cache partition.
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Turn on Adaptive Battery and consider Light performance mode.
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Test Safe Mode.
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Try LTE if 5G is weak.
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Screenshot everything and contact Samsung if idle drain continues.
Most people who follow the list in order see cooler temperatures and steadier battery numbers inside a day. A smaller group will need the official follow-up package that has not landed yet.
What This Means If You Are Shopping or Waiting
If you already own an S24 Ultra or S25 Ultra, treat the July update with caution only if you have not installed it yet and can wait. If you already installed it and feel fine, you may simply be lucky. Keep an eye on battery graphs for a few days anyway.
If you are about to buy, the hardware on both phones remains excellent. Cameras, screens, and build quality did not suddenly fail. This looks like a software collision, not a design death sentence. Waiting a couple of weeks for a corrective drop is reasonable if your upgrade is not urgent.
Earlier April pain eventually eased. July pain will too. The open question is how many more cycles owners must endure before update testing catches these loops earlier.
Bottom Line for Hot, Hungry Ultras
The Galaxy S25 Ultra S24 Ultra battery drain issue after the July 2026 update is real for a growing group of owners. Idle power loss, excess heat, and slower charging appeared together. Community evidence points hard at a WhatsApp end-to-end encrypted backup stuck in a loop, with the processor never getting to rest.
Cancel or reset that backup first. Clear cache. Restart. Restrict background apps. Wipe the system cache partition if needed. Most affected phones calm down. If yours does not, document the proof and lean on Samsung support while the warranty still covers you.
Premium phones should not require forum archaeology after every security patch. Until the next software drop lands, the steps above are the fastest path back to a cool pocket and a full day of battery. Run them tonight. Then watch for the official fix so you can stop living on workarounds.
Still watching the percentage fall while the phone sits still? Do the WhatsApp cancel step right now, then check back once Samsung ships the real patch so you know the moment it is safe to breathe easy again.
