How Heat and Loading affect Battery Life?
Answers
Heat is a killer of all batteries, but high temperatures cannot always be avoided. This is the case with a battery inside a laptop, a starter battery under the hood of a car and stationary batteries in a tin shelter under the hot sun. As a guideline, each 8°C (15°F) rise in temperature cuts the life of a sealed lead acid battery in half. This means that a VRLA battery for stationary applications specified to last for 10 years at 25°C (77°F) would only live 5 years if continuously exposed to 33°C (92°F) and 30 months if kept at a constant desert temperature of 41°C (106°F). Once the battery is damaged by heat, the capacity cannot be restored.
According to the 2010 BCI Failure Mode Study, starter batteries have become more heat-resistant. In the 2000 study, a rise in temperature of 7°C (12°F) affected battery life by roughly one year; in 2010 the heat tolerance has been widened to 12°C (22°F). Other statistics reveal that in 1962, a starter battery lasted 34 months; technical improvements increased the life expectancy in 2000 to 41 months. In 2010, BCI reported an average age of 55 months for starter batteries, with the cooler North attaining 59 months and the warmer South 47 months. Colloquial evidence in 2015 revealed that a battery kept in the trunk of a car lasted one year longer than if positioned in the engine compartment.