How come the laptop is fully charged and it takes half an hour to show that the battery is low?

Nowadays, notebook computers are particularly common, and they are used outdoors and indoors. Especially outdoors, notebooks are powered by batteries. After a long time, we will find that the battery life is not as long as it was. It used to last for three hours, but now it can only last for two and a half hours. What's going on here? The shorter battery life is not the problem of the battery itself. For the battery that has been used for less than 1 year, the battery life is often shortened not because of the normal aging of the battery, but because the notebook BIOS system misjudges the battery power during multiple charging and discharging. Originally, the battery still had a certain amount of power, but the BIOS mistakenly thought that the power was exhausted and forcibly shut down the laptop. If this battery life is shrinking, first of all, don't rush to the conclusion that it is a battery quality problem, but we can make the remaining power fully play through the simple and easy method of "battery correction". There are more than one method to calibrate the battery, and there are usually three methods: using the battery calibration program in BIOS, manually calibrating the battery and using the third-party battery calibration software. Here mainly talk about the first two correction methods. Tip: Third-party battery calibration software is not recommended. As for the reason, first of all, you need to install third-party software, which is not as simple as the first two methods; Secondly, in fact, the correction principle behind it is similar. There are not many unique places in third-party software, and there are security risks. Therefore, it is not recommended to use third-party software when the first two methods can complete battery calibration. Standard calibration method: Using the battery calibration function in this BIOS, many brands of notebook computers have integrated a battery calibration program in their own BIOS, which is called "battery calibration" in common English, that is, "battery charge calibration". Direct access to the BIOS of this notebook can complete the operation of battery calibration. Here, take ASUS notebook as an example, and briefly talk about how to operate it. Other notebooks operate in a similar way. Step 1: Start the computer, and press F2 to enter the BIOS menu after the startup screen appears; Through the left and right arrow keys, select to enter the power menu. Step 2: Enter the power menu, and you will see the option "Start battery calibration" (figure 1), select it and press enter to execute. ● Figure 1 Select the "Battery Calibration" program Step 3: At this time, the screen will turn blue, and there will be an English prompt asking to plug in the power adapter of the notebook to charge the battery. After the battery is fully charged, the screen will prompt the user to disconnect the power adapter (Figure 2). After that, the notebook will continue to discharge the battery until the battery is exhausted ● Figure 2 Follow the on-screen prompts. Step 4: This process will take some time. When the battery is exhausted, it will automatically turn off, and then connect the power adapter to charge the battery, but don't turn it on. After the charging is completed (the charging indicator goes out), the battery calibration process is completed. Editor's comment: This operation is a relatively official battery calibration method, and the whole process takes about 4-5 hours, which is time-consuming. If you find that your laptop battery has not been used for a long time, such as a few months, the battery life is not as good as before, and this BIOS has this function, it is recommended to realize it. Counterfeiting correction method: let the notebook computer start naturally. Some notebooks can't find the battery correction option in the BIOS. Can't such a notebook be battery calibrated? In fact, we can operate through the "cottage version" of the battery correction method. It is called "shanzhai" because it is not an officially announced method, but through some manual settings, the notebook is discharged in normal work until it is automatically turned off. Tip: On the surface, the process of battery calibration is to charge and discharge the battery, but its purpose is not to activate the battery as we imagined, because the current notebook batteries are all lithium batteries, and there is no activation problem. The real purpose of charging and discharging is to let the computer know the capacity of the battery again. Therefore, it is necessary to discharge as clean as possible, so that the notebook computer can work with low power and the correction effect is good. The following describes the necessary operation steps of manual battery calibration. Step 1: The laptop is in the operating system (taking Windows XP as an example), and enter "Power Options". Select "Power Scheme" as "Always on", set "Turn off the monitor" and "Turn off the hard disk" as the shortest time, and set the system standby to "Never" (Figure 3). ● Figure 3 Setting power options Step 2: In the "Alarm" of "Power Options", cancel all alarm options (Figure 4) so as to completely exhaust the battery until it is turned off. ● Figure 4 Cancel the power alarm function Step 3: After setting, close all applications, turn off WIFI, unplug the power adapter and use the battery for power supply. Don't do anything until the battery is exhausted and automatically turned off. This process is estimated to be long and may take several hours. After discharging, connect the power adapter and charge the battery, and then complete the battery calibration. After calibration, try to see if the battery life has increased. If it is not obvious, you can do it again according to the above method, but it is not recommended to do it often. If the battery is used for a long time, the effect is not obvious after battery calibration, which may be due to the natural aging of the battery itself. In addition, if the battery life of the notebook is normal, we do not recommend battery calibration.