The Anti-virus Times

czwartek, 11 grudnia 2025

User reviews for all sorts of mobile apps sometimes include complaints about an app’s power usage—how quickly the phone’s battery drains while the app is running. Such feedback also appears, albeit infrequently, in reviews of various vendors’ antiviruses, including Dr.Web. In today's Antivirus Times publication, we will try to figure out whether an antivirus does consume that much energy and how running apps affect a mobile device’s battery life.

Key aspects of power consumption by apps

To better understand how different apps can increase battery usage, we need to identify the actual energy consumers, and those are the hardware components.

Modern mobile devices incorporate quite a few hardware modules, including:

• Computing hardware (the CPU, coprocessors and controllers);
• Communication modules (transmitting and receiving antennas, signal transmitters and amplifiers);
• Input/output modules (cameras, microphones, sensors, display, speakers, vibration motors, etc.);
• The power subsystem (the battery and power management IC as well as additional modules, such as the wireless charging receiver).

All of these subsystems are managed by software—by both low-level firmware and system and user apps. To perform its tasks, the software utilises available hardware features, which involves using battery power. And the more frequently, extensively and inefficiently a certain program uses hardware components, the faster the battery will drain. That’s why the battery life of any mobile device depends so much on the overall system load generated by running apps.

Let's consider an antivirus as an example to see what actually happens. Current power usage on a device running an antivirus is affected by tasks the app is performing. For example, running an antivirus in the background will somewhat increase the device’s CPU, memory and disk usage. However, a properly designed and optimised product, whose code is well-written, won’t be using a lot of power. In order to provide resident protection in the background, the app is monitoring the files that are being created or modified and watching out for suspicious processes. In this mode, an antivirus keeps its CPU and memory usage (and, consequently, its power consumption) low.

Any antivirus also needs to update its virus databases regularly. This feature usually works automatically (as, for example, is the case with Dr.Web products). To download updates, the antivirus uses network connectivity to access the Internet and, therefore, makes use of signal transmission modules. In addition, many antivirus apps take advantage of cloud-based services to analyse suspicious files, which also involves exchanging data over the Internet. Performing all of these tasks increases power usage, but it is worth mentioning that antivirus-related communications will only account for a fraction of a modern smartphone's daily traffic—a mere drop of water in the “ocean” of data.

On-demand file scans are yet another regular antivirus routine. In this mode, especially when a full system scan is running, an antivirus uses the CPU and memory more extensively than it does in the background. However, power usage during scanning will also vary greatly depending on:

• The frequency of file scans and their depth;
• The number of items to be scanned, including files on removable media;
• Antivirus scanner algorithms and code optimisation: as noted above, well-optimised apps use the CPU and memory more efficiently and minimise their impact on battery life;
• Concurrent tasks being performed by other programs. In this case, overall CPU and memory usage may spike and drain the battery more quickly. In addition, Android may incorrectly assess the antivirus’s power consumption if multiple apps are using the CPU and memory extensively;
• Hardware features: the CPU’s clock speed and battery health. A powerful and efficient CPU can process scanning-related data more quickly and thus reduce the time spent working under a high load. Battery health, on the other hand, affects the battery's output when multiple applications are consuming power; old batteries drain noticeably faster if the device is using a lot of power.

The tasks listed above are associated with typical antivirus routines. But, bear in mind that certain products may also include additional features. For example, Dr.Web Security Space for mobile devices incorporates auxiliary protection components, such as the Firewall, Anti-theft, Parental Control, and Call and SMS filter. Their activation and background operation also claim their share of CPU and memory usage. But when matched against the overall energy consumption on the device, their impact is insignificant. For instance, the Anti-theft does not use the GPS module or other communication components unless it receives a corresponding command from the user and, therefore, makes do with very little power. The same applies to the other components except the Firewall, which we're going to consider separately.

When enabled, the firewall runs continuously in the background to monitor incoming and outgoing traffic. Under Android, it uses VPN features to intercept and analyse every data packet being transmitted via the device, without obtaining root privileges. Resident filtering inevitably involves constant CPU usage. However, its actual impact on battery life will greatly depend on the amount of traffic generated by the apps on the device. So, the more a device owner uses network connectivity (to watch videos, download files, play games, and update apps frequently), the more work the firewall will have to do and, consequently, the more power it will use.

How to track the antivirus’s impact on battery life in Android

Android settings provide access to power consumption statistics, allowing users to keep track of how specific apps use the battery. To view the data, navigate to the phone settings, locate the "Battery" section, and in the menu that appears, find the battery usage item (the actual UI terminology may vary depending on the device manufacturer). In the list that opens, you will see your apps sorted by battery usage and their respective usage percentage for a certain time period (usually the last 24 hours or since last fully charged). Most Android versions also enable users to view detailed statistics for each app to see exactly when the battery was being used heavily (when the user actually interacted with an application) and the time related to its background activity (when the app continued to operate unobtrusively).

Third-party tools for monitoring energy consumption are also available. Some of them can provide more detailed information. Bear in mind, though, that neither these third-party apps nor Android system tools can generate perfectly accurate power usage statistics for each application. The available data always represents reasonable approximation.

Mobile devices are not equipped with electricity meters connected to each hardware component—let alone meters linked to each and every running app. Furthermore, the power consumption rate is never constant for any of the components and modules and always depends on the tasks being performed and the respective module's usage mode, which complicates matters even more. As a result, actual electric-current measuring is replaced with formulas and calculation models based on how extensively specific apps use certain hardware components. For example, Android can only estimate how long it takes for the CPU to complete tasks related to a certain app or how often the app uses network connectivity. The OS uses this data to provide a virtual representation of power consumption by dividing the approximate electric energy consumption of all of the hardware components among those apps that have been using them. The data is then aggregated for each application and included in the statistics.

It is also worth mentioning that indirect evaluation models are not solely responsible for the inaccuracy. As mentioned above, multitasking and concurrent use of the hardware components by multiple applications and processes also increase the margin for error.

To estimate more accurately how much power your antivirus uses, you can monitor how quickly the battery drains while it is running at a time when the impact of other apps is reduced to a bare minimum. For example, start a full system scan and refrain from using your device in any way for as long as the scan is running. Then you will be able to match the estimated battery life prior to the scan against the estimate after the scan’s completion and make your own evaluation as to how much power the antivirus scanner can use. In a similar fashion, you can also estimate its power consumption in the background by matching your device's battery drainage overnight with the antivirus running against its battery use on another night without using the app. Please also note that it is imperative that the device usage conditions are as similar as possible in both scenarios.

What to do if the antivirus is draining the battery very quickly

Now we have established that an antivirus’s impact on battery life may vary, depending on certain conditions, but more often than not, it is quite moderate. If you suspect the exact opposite is happening and the system data indicates that the antivirus's battery usage is too high, try to understand how the way you are using your device is affecting the app's operation. If you interact with your device a lot—by installing new apps frequently and transmitting a lot of data (which includes using instant messengers and a browser cache)—the antivirus is also compelled to operate at its maximum capacity to constantly scan the data for threats. A running firewall and other optional components can also contribute to its increased power usage. Multitasking (which we discussed earlier) exacerbates the situation even further. In this case, the load on the battery will increase, but the operating system may falsely ascribe the increased power consumption to the antivirus instead of a system service or because of component access conflicts.

And to reach a more accurate diagnosis, you may want to monitor the power consumption of the antivirus personally with as little interference as possible (using the method described above). It can also be a good idea to check the app’s settings. Chances are that your antivirus is running scheduled full system scans way too often.

Finally, the issue may be caused by inevitable battery degradation, and the antivirus’s impact is merely making it more conspicuous. Some devices may display information about their current battery health as a percentage. With a degraded battery, you won't be able to use your device extensively for a long period of time without recharging it.

In any case, always remember that a spike in battery usage may be a good reason to sit down and figure out what is actually happening rather than simply wipe the antivirus off your phone. If you can't solve the problem on your own, try contacting technical support.