Battery overcharging may be caused by _____.

Battery overcharging can occur primarily due to issues within the vehicle's charging system, such as a malfunctioning voltage regulator, which can lead to excessive voltage being sent to the battery. This excessive voltage prevents the battery from properly regulating its charge, resulting in overcharging. Additionally, improper use of a battery charger, such as selecting the wrong charge rate or leaving the charger on too long, can also contribute to overcharging.

Both a faulty vehicle charging system and improper use of a battery charger can independently cause battery overcharging. This dual aspect highlights the importance of ensuring the vehicle's charging system is functioning correctly and using a battery charger appropriately to prevent damage to the battery or vehicular electrical components.