Samsung’s July 2026 security update is draining batteries and triggering overheating on Galaxy S25 Ultra and S24 Ultra devices, according to a growing number of user reports. Owners describe devices losing 5% to 7% of charge per hour while idle, with some seeing total battery life collapse to just over two hours. Samsung has not yet publicly acknowledged a software defect.

The complaints began surfacing on Samsung’s official community forums and Reddit shortly after the patch rolled out. PCMag Australia first aggregated the reports on July 29, noting that users across multiple threads are experiencing rapid battery drain, elevated temperatures, and slower charging — all traceable to the update’s installation.

The July Update’s Toll on Galaxy Batteries

The July 2026 security patch was supposed to be routine. Instead, for an unknown subset of Galaxy S25 Ultra and S24 Ultra owners, it brought a cascade of power-related problems.

One Galaxy S25 Ultra user detailed their experience on Samsung’s forum: after updating, the phone drains 5% to 7% of battery per hour while sitting idle on a flat surface. That idle drain accounts for over 60% of the total battery drop. The result: just 2 hours and 10 minutes of usable battery life from a device that normally lasts a full day.

Heat is another common thread. Multiple owners report that their phones run noticeably hotter than before, even during light use. “Even after installing the July update, I’m still facing heating issues,” wrote one user on the European Samsung Community. “Earlier, the heating was minor, but now my device is overheating.” Charging speeds have also taken a hit, with some users finding that their phones now charge more slowly.

These are anecdotal reports, not a confirmed, model-wide failure. But the volume of similar complaints across different forums suggests a real pattern worth taking seriously.

A Closer Look at the Symptoms

The battery drain doesn’t behave like normal background activity. Users report the phone failing to enter deep sleep mode — a critical power-saving state. Instead, something keeps the phone awake, even with the screen off and no active apps.

The overheating often accompanies the drain, pointing to a process running in the background that consumes CPU cycles and battery. For some, the phone gets hot to the touch, raising concerns about long-term battery health.

Not every S25 Ultra or S24 Ultra owner is affected. The problem appears intermittent, but for those hit, the impact is severe enough to undermine the phone’s usability. That’s particularly frustrating because the July update is a security patch, not a feature drop — users expect it to be safe.

WhatsApp Backup: A Culprit or a Symptom?

A curious finding by some affected users points a finger at WhatsApp. One Reddit user, dapotatopapi, discovered that the WhatsApp backup process was stuck in a loop. Disabling backups stopped the excessive drain and overheating. That fix came at a cost: they couldn’t restart the backup, leaving chat data unprotected.

Other users have corroborated the WhatsApp connection on Samsung’s forums. A stalled backup can keep the phone awake, prevent deep sleep, and generate heat — all consistent with the reported problems. But this isn’t a smoking gun. Some owners report similar symptoms without identifying WhatsApp as the cause. And even if WhatsApp is involved, the trigger may still be the July firmware, which might have altered how background services are managed.

Think of it this way: a system update can expose or aggravate an existing app behavior. Like a Windows patch that reveals a driver conflict, Samsung’s July update might have changed something that makes WhatsApp — or another app — misbehave. The root cause could be the app, the firmware, or a combination.

Practical Steps for Galaxy Owners

If your Galaxy S25 Ultra or S24 Ultra is draining fast or running hot after the July update, don’t immediately factory reset or seek an unofficial downgrade. Start with diagnosis.

Open Settings > Battery and device care > Battery and check for apps with abnormally high background usage. WhatsApp is a prime suspect, but also examine cloud sync clients, VPNs, carrier services, location-hungry apps, and anything recently updated via the Galaxy Store. All can cause sustained background activity.

Try these steps:

  • Update all apps — both from Google Play and the Galaxy Store — and restart the phone. An app-level fix may resolve stuck processes.
  • For WhatsApp specifically, check if a backup is in progress or stalled. If it’s stuck and draining battery, you can temporarily disable backups, but be aware you won’t be able to save new chat data until it’s re-enabled. First ensure your chats are backed up elsewhere or that you’re willing to risk data loss.
  • Allow the phone to settle for a few hours after any firmware or app update. Sometimes the system rebuilds caches, and battery use normalizes after a day or two.
  • If overheating or rapid drain continues, submit an error report via the Samsung Members app. Include battery usage screenshots and the exact update version installed (find it under Settings > About phone > Software information). Samsung’s engineers use these reports to identify patterns.

Avoid drastic measures like a factory reset unless the phone becomes unusable. A downgrade to earlier firmware is risky and often not possible without voiding warranty or tripping Knox.

The Security Patch Dilemma

This situation creates a tough choice. The July 2026 update is, at its core, a security patch. Skipping it leaves your phone vulnerable to known Android and Samsung-specific vulnerabilities that the patch addresses. Installing it may saddle you with battery woes.

For now, the safest path is to apply the update but monitor performance closely. If the battery drain makes the phone unreliable, you might consider rolling back — but only as a last resort and with full awareness of the security trade-off. Samsung may release a hotfix if the issue is firmware-based. If an app like WhatsApp is the real problem, a server-side or app update from Meta could resolve it without waiting for Samsung.

What to Watch Next

Samsung hasn’t commented, and there’s no timeline for a fix. Keep an eye on official channels — Samsung Members notifications, carrier update pages, and tech news outlets. The pattern here is familiar: a monthly security patch introduces instability, users raise alarms, and a follow-up update arrives within days or weeks.

In the meantime, use the diagnostic steps above. The more data Samsung receives through error reports, the faster the root cause can be pinpointed. And if you haven’t installed the July update yet, consider holding off for a few days to see if a revised version appears — but remember that delaying security patches carries its own risk.

For Galaxy S25 Ultra and S24 Ultra owners, the next few days will be telling. Either Samsung acknowledges the problem and promises a fix, or workarounds spread until an official patch lands. Either way, your battery life shouldn’t be held hostage by a mandatory security update.