What is a common sign that a laptop's battery needs replacement?

A common sign that a laptop's battery needs replacement is when the laptop runs on AC power only. This condition typically indicates that the battery can no longer hold a charge, meaning that while the laptop can function when it is plugged into a power source, it won’t operate independently on battery power. This is a clear indication of battery failure as it directly impacts the mobility of the laptop, which is one of its key features.

While prolonged charging times can suggest battery wear, it does not always mean that immediate replacement is necessary, as there could be other causes such as charger issues. A flickering screen might relate to graphics driver problems or hardware issues rather than battery condition. Overheating can be caused by several factors, such as dust buildup or thermal paste degradation, which are not specifically indications of battery health, making them less reliable indicators for battery replacement needs.