What does a battery charger do?

A battery charger is specifically designed to replenish the charge in a discharged battery. When a battery loses its charge due to use, the charger applies an electric current to restore the necessary voltage levels, enabling the battery to store energy once again. This process typically involves converting AC power from an outlet into DC power suitable for battery charging, ensuring the internal chemical reactions can resume, allowing the battery to function correctly after being depleted.

While measuring the voltage of a battery, checking for leaks, and cooling during operation might be important aspects of battery maintenance or safety, they are not the primary functions of a battery charger. The central role of the charger is to ensure that batteries are restored to their full operational capacity, which is essential for reliable performance in various applications.