Car Battery Life - How Long Does a Car Battery Last

Battery life is defined as the period of time in which a battery is capable of being recharged and retains the charge applied. Once the battery is no longer capable of being recharged or cannot retain its charge properly, its useful lifetime reaches its end. The main cause of this "death" is the sulphation process. This begins when lead sulphate precipitates over the battery plates, coating them and preventing the reactions which produce the electric energy.

The life-span of all batteries is linked to the capacity of the battery (e.g. in Ampere hours) and the amount of current (Amperes) drawn from the battery by the device which it powers. Temperature, humidity and other environmental factors also have an impact on battery life-span.

Under ideal conditions, one automobile battery can last up to six years, but several factors decrease this optimal lifetime. A study of 2,769 sample 12 volt batteries conducted in 2004 showed that the average lead acid battery life is 50 months. Batteries in the northern US had an average life of 56 months compared to those in the south which had an average life of 43 months. Lead acid batteries last longer in cold climates as warm climates increase water loss and sulfation. Car battery life span range is 2 to 5 years.

The most simple and effective way to extend the life of an automotive battery is to keep it charged close to 100%. Periodically check the state of charge of your battery (see How to measure open circuit car battery voltage) and charge it with a dedicated charger device when necessary (see How to charge a car battery). Consequently, try to avoid deep battery discharges that can happen, for example, if you leave your car's lights on.

Hybrid car battery life expectancy and electric car battery life expectancy is about 8 years.