Charging a smartphone overnight is safe, but it affects battery life

The habit of leaving a smartphone connected to a charger overnight is not a major issue in terms of safety, but an analysis has found that it can affect battery life. According to explanations from Samsung SDI and smartphone manufacturers, after a full charge, supplementary charging is repeated to maintain the remaining battery level, and during this process, a high state of charge and heat can accelerate battery aging. However, latest smartphones are equipped with protection circuits, so the risk of explosion due to overcharging is low. Experts advise avoiding excessive heat generation during charging and using battery protection or optimized charging features as practical ways to manage battery health. In particular, they explained that it is best to avoid environments where heat does not dissipate well, such as wireless charging under a blanket or pillow, or with a thick case on.