1. The charger is not the original charger. The non-original charger purchased in the mobile phone supermarket will lead to unstable voltage, slow charging, and poor compatibility.
2.USB charging cable or interface is not the same, the appearance is the same, the actual wire support current, or the interface is not the same, especially there are some differences at the interface.
3. Low temperature environment and high temperature environment will also affect the speed of charging. If the temperature is too low, the charging will be slow or unable to be charged. If the temperature is too high, the battery will be damaged.
4. The USB interface has impurities, and it is not cleaned up in time, which will cause poor contact and intermittent charging, resulting in slow charging speed.