Battery Basics: Experts Warn Against Overnight Charging Habits
A large number of smartphone users routinely leave their phones charging overnight to wake up with a full battery in the morning. However, experts caution that this common habit may be harmful to battery longevity in the long run.
Chao-Yang Wang, Director of the Electrochemical Engine Center at Pennsylvania State University, explained that, "Repeatedly charging a battery to 100% accelerates its chemical aging." As a result, he noted, battery lifespan may be reduced by an average of 10–15%.
Dibakar Dutta, Associate Professor at the New Jersey Institute of Technology, advised that the optimal charge range for smartphone batteries is between 20% and 80%. He further warned that "routinely letting the battery drop to 0% can be extremely damaging."
He also emphasized that extreme temperatures—either high or low—can contribute to battery degradation. Additionally, the use of fast chargers generates excessive heat, which may further diminish the battery's long-term efficiency.
According to experts, it is acceptable to charge up to 100% when necessary, but it should be avoided as a daily routine. For sustained battery performance, they recommend slow charging and maintaining moderate charge levels.
