Have you noticed that laptop battery time estimates often vary, even when the charge percentage stays the same? This happens because several factors influence its accuracy, causing the estimate to shift unpredictably. This guide shows how laptop battery estimates are calculated and how to make them more reliable.
Content
- How Laptop Remaining Battery Estimates Work
- Factors That Can Cause Inaccuracy
- How to Improve Battery Estimate Accuracy
How Laptop Remaining Battery Estimates Work
Laptop battery estimates are calculated using a combination of hardware and software working together. Battery Management System (BMS) is an electronic control system inside batteries that tracks battery health, current draw, temperature, state of charge (SoC), etc., and reports it to the operating system.
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Pixabay
The laptop operating system takes information from BMS and laptop power sensors to understand current power consumption and battery capacity. It then provides an estimate based on current consumption. For example, if your laptop is consuming 20 watts of power and has 60 watt-hours of charge left, the system may predict around 3 hours of usage.
Although this process provides accurate readings if the usage stays the same, that isn’t the case in real-world usage. This is why modern laptops have advanced battery management systems, and some even use machine-learning techniques to calculate estimates based on historical usage data. The system looks at historical consistencies in your laptop usage to further improve accuracy.
For example, if you often play games on your laptop, the estimated battery time will be less, even if current consumption is low.
Factors That Can Cause Inaccuracy
Since multiple variables control battery timing accuracy, several factors can throw these calculations off. The following factors are the most prominent:
Frequent changes in usage patterns
The remaining battery estimate time heavily depends on your current usage, even if it takes into account historical data. If you start playing a game or using a resource-intensive program, the battery estimate will reflect it within a few minutes.
Frequently switching between programs with varying workloads can also lead to inaccurate battery estimates. This isn’t usually a problem, as you’re likely aware of the system’s current load. However, issues arise when a background app or process starts consuming excessive power without your knowledge, making it unclear why the estimate is inaccurate.
Tasks such as Windows updates, cloud storage synchronization, and app updates can noticeably impact resource usage. When these background tasks activate, your battery’s remaining time estimate may become inaccurate, even if you’re not actively using the system. If you encounter unexpected inaccuracies, check for active background processes first.
Bad battery health
Battery health inevitably degrades over time, causing low capacity and high battery drain issues. However, the laptop doesn’t account for a severely degraded or faulty battery, so when the battery capacity decreases, it can interfere with BMS’s ability to estimate the remaining charge, leading to inaccuracy.
Furthermore, a faulty battery can also face voltage sag issues where the voltage drops under heavy load. You’ll see unexpected drops in estimated time.
Low or high battery temperature
Lithium-ion batteries work best at room temperature. Both heat and cold can affect its efficiency, which could lead to inaccuracy of battery timing.
In high temperatures, the heat accelerates the chemical reactions within the battery that affect efficiency and increase the self-discharge rate. The faster discharge rate disrupts the expected discharge curves of BMS, leading to inaccurate estimates. Make sure your laptop doesn’t overheat, as it can cause inaccuracy and damage the battery as well.
Image source:
Vecteezy
On the other hand, cold temperatures slow down lithium-ion movement within the battery, temporarily decreasing battery capacity. This can confuse the BMS about the state of charge (SoC) and give inaccurate battery timing. However, this is less of an issue, as most people use the laptop at room temperature, and the laptop generates heat on its own as well.
How to Improve Battery Estimate Accuracy
While perfect accuracy is impossible, ensuring all related components are performing optimally can significantly enhance reliability. If you find your battery estimates to be unusually inaccurate or want to improve their precision, try the below options.
Keep related drivers up to date
Up-to-date device drivers ensure the optimal functioning of all laptop components. As many hardware components can impact the accuracy of battery timing, you need to make sure all the related component drivers are up to date.
The easiest way to ensure all drivers are up-to-date is to use an automatic driver updater tool to detect all outdated drivers and update them all with a single click.
However, if you intend to update drivers manually, make sure you update the following drivers:
- Microsoft AC Adapter
- Microsoft ACPI-Compliant Control Method Battery
- ACPI Thermal Zone
- Intel Power Management Interface
- Intel Dynamic Tuning Processor Participant
- Intel Chipset Device Software
Of course, you could have different drivers, depending on your laptop manufacturer, but you mainly need to ensure the drivers under the Battery, Software Devices, and Sensors sections are up-to-date.
Also make sure your laptop BIOS is updated and that you use UEFI for better support for the latest features. BIOS manages many power and battery hardware functions that can improve accuracy.
Recalibrate the laptop battery
Although battery recalibration isn’t necessary for lithium-ion batteries that power most laptops, you can still do it when you face timing inaccuracy. If the battery is consistently showing inaccurate estimated remaining battery time, recalibrating may fix the issue.
Follow the steps below:
- Charge the battery to 100%, and keep it plugged in for another 30 minutes.
- Unplug and use the laptop until it turns off due to low battery.
- Plug in the charger again, and let it charge to 100% without interruption. You can use the laptop during charging if you would like.
This will recalibrate the battery and possibly improve battery estimate timing accuracy. However, don’t do this too often, as it can negatively impact battery health.
Ensure the laptop battery is healthy
Laptop battery health is the most common reason for estimated time inaccuracy, as it always degrades over time. Thankfully, you can easily check your laptop battery using a third-party app. We recommend BatteryInfoView, a free tool that is easy to use and provides all the information you need.
Use the app to check the Battery Health section to see exact battery health in percentage. As long as it’s above 80%, you shouldn’t see any noticeable inaccuracies.
You can also click on View -> Show Battery Log to track battery behavior over time and possibly detect issues under the Event Type section.
Use a third-party battery monitoring tool
If you don’t like the laptop’s built-in tracking system, you can also use a third-party tool that uses its own algorithm to track battery usage and provide an estimate. BatteryMon is a reliable tool for this purpose that not only shows the estimated remaining laptop battery, but also allows you to track usage and consumption.
Open the app, and click on the Start graphing button in the top-right corner to start tracking. It will show a graph with a plain line and a dotted line. The plain line is your current drop in battery percentage over time. The dotted line is the expected drop based on the app’s own algorithm.
Considering that there is no significant change in usage, if the plain line is not on top of the dotted line, or at least very close, then it could mean the estimated battery isn’t accurate. If the plain line is on top throughout the discharge period, the estimate is accurate.
Furthermore, the app also has a Discharge Rate reading that shows total battery time based on current usage. This reading is not an estimate – it accurately reflects how long the laptop battery will last if the current power consumption remains constant. It’s a great feature that will check how long the battery will last under different loads, like gaming and browsing.
All the above information will ensure your laptop’s battery predictions are as reliable as possible, keeping you prepared for longer usage sessions. If your laptop battery isn’t lasting long enough to fulfill your needs, learn how to improve its battery life.
Image credit: Unsplash. All screenshots by Karrar Haider.
Karrar Haider –
Staff Writer
Karrar is drenched in technology and always fiddles with new tech opportunities. He has a bad habit of calling technology “Killer”, and doesn’t feel bad about spending too much time in front of the PC. If he is not writing about technology, you will find him spending quality time with his little family.
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