First, the phone's system malfunctioned, which caused problems with the battery level display. This problem is the easiest to solve, you can directly shut down and restart, which is equivalent to data refresh, and the general power display will return to normal. Second, the charger malfunctions. This failure is the main reason why mobile phones cannot be charged. So how to judge the charger is good or bad. It's actually very simple, try another charger. If it can be charged, it can be concluded that the charger is faulty. Faced with this kind of problem, there is no way to buy another charger. Third, the charger and the phone are in poor contact. It is also very common that the charger is not plugged in properly due to careless phone users. The solution is simple: change the jack back and forth. Fourth, mobile phone battery problems. In general, it's rare to have a problem with your phone's battery. But once there is a problem, it is a big problem and must be paid attention to. Therefore, when it is found that the charger and the mobile phone system are not faulty, the battery should be checked. If the battery is found to be swollen, then it means that there is a problem with the battery, and it must be stopped immediately. Here to give you a piece of advice, for the battery do not disassemble. Because the swollen battery is easy to cause explosion, bringing serious consequences. Fifth, the mobile phone itself has quality problems. If you buy a cottage phone, then the probability of the phone failure is very high. If it is a brand machine, it needs to be returned to the original factory.