Possible reasons and solutions for the laptop battery can not be fully filled

Recently, a friend asked that when his notebook battery was charged to 80%, it showed full charge. The charging time is about 30 minutes, and it will be out of power in 5 minutes.
According to a friend's description, it is obvious that the battery performance is degraded and the battery cannot be properly charged and put on the spot. If the laptop battery has been used for more than 2-3 years and is used more frequently, it should belong to the normal aging of the battery. If you plan to continue using the notebook, consider purchasing a new battery of the same model. If the battery is not used for a long time, such as only half a year to a year, then the battery should be saved. The easiest way is to use the battery discharge tool that comes with your laptop BIOS. After the battery is completely discharged, refill it, repeat it about 3 times, and try again. If there is no problem with the battery itself, the endurance can be restored to about 80-90% of the new battery.
At this point, you can also use the software such as Master Lu to test the battery. If the battery life is still a problem, as long as the battery is still under warranty, you can find a solution.