July 31, 2026, 2:34 pm | Read time: 3 minutes
Software updates are intended to fix bugs, deliver new features, and improve security. However, after a recent update, users of several Samsung smartphones are reporting battery issues. The Galaxy S25 Ultra and Galaxy S24 Ultra are particularly affected. Users describe significantly reduced battery life, increased heat generation, and occasional charging difficulties. The exact cause is still unclear.
Battery Drains Quickly Even in Standby
One user vividly describes his experience in the Samsung Community. After the July update for One UI 8.5 with build number S938BXXSBCZG3, the behavior of his Galaxy S25 Ultra changed immediately.
According to him, the battery level dropped from about 85 to nearly 5 percent within half a day, with the display on for only about two hours. Additionally, the device reportedly lost between 5 and 7 percent of battery charge per hour even in standby mode.
More Users Report Heat and Charging Issues
Similar observations are also found on Reddit. There, a Galaxy S25 Ultra owner reports that his smartphone was unusually warm in the morning and lost a lot of energy overnight. According to him, 25 percent of the consumption was attributed to the system interface.
In the comments, another user describes charging problems. His regularly used charger took about three hours to charge the battery from 0 to 100 percent this time. Fast charging apparently failed.
The complaints do not seem to be limited to the current flagship model. A Galaxy S24 Ultra owner also reports significantly shorter battery life after the update.
Sometimes Only Six Hours of Battery Life
Another report on the Galaxy S25 Ultra describes even more severe effects. Since the update on July 23, 2026, the battery lasts only about six hours with unchanged usage behavior. Additionally, the smartphone becomes unusually hot.
Diagnostic data reportedly showed a CPU temperature of up to 76 degrees Celsius at times, even though no particularly demanding applications were running. Despite these reports, it remains unclear how many devices are actually affected. The known information so far comes from individual user reports.
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WhatsApp Backup Emerges as Possible Cause
In one of the reported cases, a possible explanation for the increased energy consumption emerged. An encrypted WhatsApp backup was apparently running continuously in the background. This process continuously taxed the smartphone and, according to the user, increased battery consumption.
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After the backup was aborted, the energy consumption in standby mode reportedly decreased significantly. Several users on Reddit also suspect that stalled backup processes could be causing some of the problems.
What Affected Users Can Check
Those noticing the described issues can first check if a WhatsApp backup is running unusually long or is stuck with an error message. In the reported individual case, aborting the process helped.
However, it remains open whether this will work for other devices. It is also still unclear what exactly is behind the complaints. It is currently uncertain whether an update from WhatsApp or another update from Samsung will be necessary.