How does a battery charger primarily function?

The primary function of a battery charger is to convert voltage from alternating current (AC) to direct current (DC). Most batteries, particularly rechargeable types like lead-acid or lithium-ion, require DC voltage to charge properly. When a battery is connected to a power source, the charger takes the AC power available from the outlet and converts it into the appropriate DC power that the battery can absorb.

This conversion is crucial because the chemistry within the battery is designed to store and release energy in a DC form, allowing for efficient charging and discharging processes. The charging circuit must be able to manage this conversion carefully to ensure the battery is charged safely and effectively.

While maintaining battery temperature and balancing charge levels are important aspects of battery management and overall performance, they are secondary functions that may be integrated into advanced charging systems rather than the primary purpose of a battery charger. Similarly, increasing battery size is not relevant to the function of a charger. Thus, the core role revolves around the conversion of AC to DC for proper charging of the battery.