How do you check the health of a car battery?

Using a multimeter to check the voltage and performing a load test is the most effective method for assessing the health of a car battery. A multimeter allows you to measure the voltage of the battery directly. A healthy, fully charged battery should read around 12.6 volts or more when the vehicle is off. If the reading is significantly lower, it indicates that the battery may be weak or discharged.

Additionally, a load test is essential because it simulates the demand placed on the battery when starting the engine. This test involves applying a load to the battery while monitoring its voltage; if the voltage drops below a certain threshold during the load test, it suggests that the battery is not capable of delivering the necessary power for starting the vehicle.

This comprehensive approach ensures that both the voltage and the ability of the battery to perform under load are assessed, providing a clear picture of its overall condition. Observing the battery for physical damage may provide some insight into its health, but it does not quantify its performance ability. Similarly, simply charging the battery or replacing it regularly without testing may overlook underlying issues that could be addressed without replacement.