Does leaving your phone charging overnight damage the battery?

Modern smartphones are built to handle overnight charging without serious risk to their batteries, according to a report published by technology outlet SlashGear. Advanced power management systems automatically regulate the charging process and cut the flow of electricity once the battery reaches 100 percent. Samsung describes this approach as "maintenance charging," in which the phone briefly draws power at intervals to offset the natural drop in charge level. Manufacturers generally recommend keeping lithium-ion batteries within a 20–80 percent charge range and avoiding prolonged periods at the very top or bottom of the scale. Apple's Optimized Battery Charging feature stops charging at 80 percent and completes the cycle based on the user's expected wake-up time. Samsung offers comparable modes that cap charging at 80 percent or align it with the user's sleep pattern. The report also noted that high heat is the most significant factor affecting battery health, with Apple advising users to avoid charging when temperatures exceed 35 degrees Celsius. Using original, certified chargers was cited as important for both safety and performance. The report did not identify any specific safety incidents linked to standard overnight charging on current smartphone models.