The arrival of iOS 26 on millions of iPhones in Europe and the rest of the world has been accompanied by a recurring complaint: battery life is significantly reduced in the first few days after the update. Users in Spain and other EU countries have flooded forums, social media, and support communities with complaints about high battery consumption on iOS 26 , even with moderate phone use.
Apple has publicly acknowledged this situation and describes it as a temporary and expected behavior after a major system update. According to the company, the iPhone performs a series of intensive background tasks that demand more from the processor, storage, and Neural Engine, resulting in significantly higher energy consumption until the device finishes adapting to the new software.
What's happening to the battery after installing iOS 26?
What many users interpret as a bug in iOS 26 is actually an internal system "tuning" phase . Immediately after installation, the iPhone begins a series of optimization and data reorganization processes that can last between 24 and 72 hours, depending primarily on the amount of data stored on the device.
During this period, numerous iPhone 11, 12, 13, 14, 15, and 16 owners have noticed a sharp drop in battery life, increased heat, and a rapid decrease in battery percentage. Apple insists that this behavior should not persist: once internal tasks are completed, battery life tends to stabilize and may even perform better than with the previous iOS version.
The increased consumption is directly related to the system's deep redesign, the introduction of the new Apple Intelligence suite , and the massive improvements in native applications such as Photos, Maps, Music, Messages, Mail, Safari, and FaceTime, which need to reanalyze and reindex large volumes of data.
Reindexing and internal system "cleaning"
One of the biggest battery drains right after updating to iOS 26 is the content reindexing for Spotlight, the iPhone's built-in search. This service has to completely recataloge photos, videos, messages, emails, documents, and app data so that searches are fast and accurate again under the new system rules.
This massive scan runs in the background, but it keeps the processor and storage working almost continuously for hours. On devices with very large photo libraries or years' worth of accumulated messages and emails, this task can easily take more than a day, resulting in a significant drop in battery life.
Simultaneously, iOS 26 reviews and reorganizes internal data structures, regenerates application indexes, updates caches, and checks the integrity of system files. Although the user sees nothing on the screen, a true "reset" is taking place, optimized to ensure everything runs smoothly in the new environment.
In this context, it is common for the iPhone to consume more battery even when idle , since many of these processes run precisely when the device is locked or not in apparent use.
Apple Intelligence: the new AI and its energy cost
The other major factor contributing to high battery consumption in iOS 26 is Apple Intelligence, the generative artificial intelligence suite that Apple has deeply integrated into the system. Unlike other solutions based almost entirely on the cloud, a significant portion of Apple Intelligence's processing is done directly on the iPhone, with the aim of enhancing privacy.
During the first few days after the update, the system must prepare models, adjust algorithms, and "learn" user habits. This means that the neural engine and processor work at full capacity to adapt features such as Siri's contextual responses, summarizing and rewriting text in Mail, real-time audio transcription in calls or voice notes, and generating content like Genmojis or images with tools like Image Playground.
All these capabilities require an initial training phase using local data: the iPhone analyzes how you type, which apps you use most, what kind of photos you take, and what music you listen to. This learning curve is particularly demanding in terms of energy consumption, so the battery drains faster in the first few days than once the system is running smoothly.
This internal effort is complemented by integration with external services like ChatGPT for more complex queries. Although the bulk of the AI ​​processing is done on the device, managing secure connections to servers and integrating responses also adds extra bandwidth consumption , especially with frequent use.
Once this setup and adaptation stage is over, Apple maintains that Apple Intelligence can even help save energy in daily tasks by making more efficient decisions about how and when to activate certain processes.
iPhone models most affected by iOS 26
The impact of high battery consumption is not the same for all users. Older models compatible with iOS 26, such as the iPhone 11, 12, or the second-generation iPhone SE, are the most affected during the optimization phase.
These devices have less efficient chips compared to newer processors, and in many cases, they also have batteries that are partially degraded over time. As a result, Apple Intelligence's reindexing, recalibration, and configuration tasks can take longer to complete and place a sustained strain on the hardware, making the feeling of power drain more pronounced.
On the other end of the spectrum are the more recent models, such as the iPhone 15 family, the iPhone 16, and their Pro variants, equipped with chips like the A17 Pro and higher . These CPUs and their neural engines are specifically designed for intensive AI workloads and are more energy efficient, completing background tasks faster and with less impact on battery life.
Even so, high-end devices may experience a drop in battery life in the first few days after the update, although this usually stabilizes within one or two charge cycles . On older models, this period can last several days longer, especially if the user has many photos, videos, and apps installed.
This difference in behavior explains why some iPhone 16 owners barely notice the problem, while others with an iPhone 11 or 12 describe a "dramatic" drain on battery life right after upgrading to iOS 26.
Battery status recalibration and abnormal readings
Another element that confuses many users is the battery system recalibration that accompanies major updates like iOS 26. The software needs to relearn how much real capacity the battery has and how it responds to new energy demands.
During this phase, the percentage displayed in the status bar may fluctuate unusually : rapid drops, jumps of several points in a few minutes, or seemingly inconsistent battery life estimates. This doesn't necessarily mean the battery is damaged; it simply means the system is adjusting its calculations based on new usage patterns.
In the "Battery" section, under "Battery Health & Charging," iOS 26 updates the maximum capacity and peak performance estimates. After recalibration, your device may display a slightly different value than before the update, but this is part of the fine-tuning process of the power management system.
Apple explains that this recalibration contributes to better long-term battery management , although during the first few days it may increase the perception that the battery drains faster than usual.
New features in native apps that drain the battery
Beyond the core system and Apple Intelligence, iOS 26 introduces significant changes to many native apps that also impact battery life, especially initially. The Photos app is one of the best examples: it rescans the entire library to improve recognition of people, pets, places, and objects , creates automatic collections, and enhances smart search.
This background analysis can last for hours if the user saves thousands of photos and videos , keeping both the processor and the neural engine busy. The result is increased battery consumption, even without explicitly opening the app.
In Apple Music, the "AutoMix" feature uses AI algorithms to generate smooth transitions between songs, almost like a virtual DJ. To do this effectively, it analyzes the user's music library, identifying rhythms, tones, and song structures. This initial analysis results in a temporary spike in activity when the app is used for the first time after an update.
Maps, meanwhile, incorporates more detailed topographic routes and improved offline map navigation. To make these new features available, the system downloads and processes additional data packages , especially when using large areas or multiple European countries, resulting in increased battery consumption during these operations.
Other apps like Messages, Mail, Safari, or FaceTime also add features that require a brief initial setup period : text effects, smart email categorization, detection of relevant information on web pages, or live transcription during calls, all powered by AI models that primarily work on the device.
Apple's recommendations and best practices for the user
In response to a wave of complaints about high battery consumption in iOS 26, Apple has published several recommendations aimed at reducing the inconvenience while the system finishes optimizing. The main one is simple: leave your iPhone charging overnight , connected to a stable Wi-Fi network, for the first few days after the update.
By doing so, the device can perform the most demanding reindexing and analysis tasks without relying on the battery or interfering with daily use. In fact, many users have noticed a significant improvement in daytime battery life after a couple of nights with their iPhone plugged in and not using it intensively.
Another guideline the company suggests is to avoid particularly demanding activities immediately after updating: games with very advanced graphics, long augmented reality sessions, 4K video recording or editing, or prolonged GPS navigation. Reducing these types of activities in the first 24-72 hours helps the system complete its internal processes more quickly.
Apple advises against restoring the iPhone to factory settings as an immediate response to high battery consumption, as this completely restarts the indexing and learning processes when data is restored, further lengthening the adaptation period and, therefore, the time of high battery consumption.
In parallel, it is recommended to frequently check the "Battery" section in Settings to see which apps are using the most energy, and check the App Store for updates to those applications , as many developers release versions optimized specifically for iOS 26.
How to adjust iOS 26 to reduce battery consumption
Beyond the official guidelines, there are a number of practical adjustments users can make to minimize the impact of high power consumption while iOS 26 is still being rolled out. The first is to control screen brightness , which is responsible for a significant portion of daily energy use.
Manually reducing the brightness or enabling automatic brightness with a moderate base level can make a difference, especially outdoors. It's also advisable to shorten the auto-lock time so the screen turns off sooner when the device isn't in use.
Another effective measure is to disable Background App Refresh for non-essential apps. From Settings > General > Background App Refresh, you can restrict this behavior to specific apps or even disable it entirely for mobile connections, which helps to limit resource consumption while the system performs its own optimization processes.
Turning off Wi-Fi, Bluetooth, or location services when not in use also helps reduce battery consumption, although it's advisable to keep Wi-Fi active during the nights of the first few days after the update if you want iOS 26 to complete pending downloads and indexing as quickly as possible.
Finally, activating Low Power Mode can be helpful during this phase: it limits background tasks, reduces visual effects, and slows down automatic downloads, helping to extend battery life when the system is still particularly active.
iOS 26 compatibility and restricted features
However, not all features behave the same across all devices. Apple has limited the most advanced Apple Intelligence features to models with newer hardware and neural engines capable of smoothly handling those workloads. In practice, this means that certain generative AI options are reserved for the latest generation iPhones.
This strategy aims to prevent older models from experiencing excessive performance degradation or even higher power consumption if they attempt to run the same complex functions. The company prefers to maintain a reasonable user experience across as many devices as possible, even if this means some performance differences between models.
In any case, even on iPhones where Apple Intelligence is scaled back, iOS 26 introduces improvements in security, stability, and overall performance, with the promise of further refining energy consumption through future minor updates.
The high battery consumption in iOS 26 is due to a combination of massive data reindexing, power system recalibration, initial Apple Intelligence setup, and the introduction of advanced features in native apps that largely operate within the device itself. While the first few days after the update can be frustrating, especially for those using older models like the iPhone 11 or 12, evidence and Apple's explanations point to a temporary phenomenon that tends to stabilize within two to four days , at which point battery life returns to normal levels and may even improve compared to previous versions of the system.
