Summer heat can be fatal to car batteries
Drivers in Western Pennsylvania are quite familiar with the frustration of trying and failing to get their vehicle started on a bitterly cold winter day as their battery fails to deliver sufficient power.
While it’s well known that freezing cold weather can wreak havoc with car batteries, the opposite is also true. Scorching summer heat can also shorten the life of a car battery.
In fact, according to Mike Maxin of Butler RV Center, summer heat may actually be more harmful to the long-term health of a car battery than wintry cold conditions. Maxin says he replaces 20 to 30 car batteries and 50 to 100 RV batteries per year.
“Both extreme heat and cold can negatively impact a car battery, but heat generally causes more long-term damage,” Maxin said. “While cold primarily affects a battery’s ability to deliver power, summer heat can lead to internal corrosion and evaporation of battery fluids, weakening the battery’s structure and capacity. While cold temperatures can slow down the chemical reactions within the battery, reducing its ability to start the car, the battery itself is usually not structurally damaged by the cold.”
According to a news release, AAA East Central — which covers parts of Kentucky, New York, Ohio, Pennsylvania and West Virginia — has received more than 80,000 calls for battery issues since the start of 2025.
“While we rescue millions of motorists at the roadside during the summer, many of those breakdowns are preventable,” said Matt Philips, operations manager of automotive services. “One thing you can do to avoid a potential breakdown is have your car battery tested, especially if it’s more than three years old.”
Most vehicles are started by 12-volt lead-acid batteries and even electric vehicles use them to power certain components. There are a few exceptions, such as Tesla’s Cybertruck, which are powered by a 48-volt electrical system.
According to Maxin, a battery in a brand-new vehicle can usually last between three and five years or, if proper care and maintenance is kept, as long as six or seven years.
Extreme heat and cold aren’t the only factors which can drain the life of a car battery. Sometimes the carelessness of the vehicle operator can lead to unnecessary early battery replacements.
“Another major thing that greatly reduces a battery’s life is when somebody leaves a light on or a door open, and the battery drains down to where it is totally dead,” Maxin said. “Every time this happens it shortens the life of the battery due to sulfation inside the battery when it is dead.”
Car batteries can also go dead whenever the car sits idle for monthslong periods.
