Heat Promotes Processes That Deteriorate Internal Components, Causing the Battery to Lose Capacity and Starting Power

High temperatures can accelerate the wear of a car battery and shorten its lifespan, according to experts. Heat promotes processes that deteriorate internal components, causing the battery to lose capacity and starting power. The battery is essential for starting the vehicle and powering various electrical systems.

Checking its condition before and during hot months can help prevent unexpected failures. In lead-acid batteries, rising temperatures speed up internal electrochemical reactions. According to the American Automobile Association (AAA), this process can promote corrosion of the metal grids that form part of the internal plates.

Joseph Liedhegner, director of engineering at battery manufacturer Clarios, noted that corrosion of these grids is one of the most frequent failure mechanisms in lead-acid batteries. Over time, this wear causes the battery to lose capacity and starting power until it stops working entirely. Heat can also cause battery fluid to evaporate faster, which accelerates deterioration of internal components and corrosion.

Additionally, vibrations during driving can further speed up wear. The temperature under the hood can be even higher than outside, as ambient heat combines with engine-generated heat. AAA warns that a car parked in the sun can also reach very high interior temperatures.

One key measure is performing a preventive check before periods of extreme temperatures. Specialists recommend testing battery voltage and conductance, inspecting terminal condition for signs of corrosion, and verifying the battery is properly secured. Poor fastening can increase vibration effects and contribute to deterioration.

On hot days, parking in a garage or shade reduces vehicle and component temperatures. If that is not possible, a reflective sunshade can reduce interior heating. Regularly checking the battery is also advisable—bluish dust on terminals or a swollen casing may be signs of deterioration requiring professional inspection.