Q: Can a Car Battery Overheat in Hot Weather?

People often only think a battery will get damaged in the winter. However, the summer heat can be even more damaging than the winter’s cold temperatures when it comes to car batteries. The summer heat is when most of the damage is done to a battery from internal corrosion or fluid evaporation.

When temperatures start climbing above 90 degrees Fahrenheit and the under-hood temperatures above 200 degrees, these temperatures can cause the battery to accumulate corrosion on the terminals and sulfate the internal plates along with cause the fluid in the battery to evaporate. The battery can only take this heat for a season or two if no [maintenance is done to clean the battery and refill the battery with distilled water.

When a battery has gone through a hot summer, it will start to diminish in its capability to store and maintain the voltage and amperage levels as it could when it was new. The battery, even if it is well maintained, will still lose capacity as time goes by. In extreme hot and cold climates it will lose capacity even faster. After a hot summer, the battery will be more prone to failure when the weather gets cold again.

If the battery is used in extreme hot or cold weather, it will not last much longer than two to four years. When a battery has a larger cold cranking capacity, the cost of the battery rises sharply, due to the added lead put into the battery when it is made. I have seen batteries last five or more years before any failures due to the high lead content in them. Most new batteries are designed to last about three years. When you go to purchase a battery you will see a warranty of between two and five years. The longer the warranty, the more lead it will have and heavier the battery will be. You will get what you pay for.

If a battery has more warranty, lead, or capacity, it does not mean it will not fail in extreme hot temperatures any less than a battery that has less warranty, lead or capacity. Some batteries are better made with better materials and will withstand extreme temperatures better. It is like buying a car; sometimes you get one that never has a problem and another that is a lemon and has nothing but problems. Have your battery tested and maintenance done on a regular basis and you will find that doing this will help your battery last longer and you will have a smaller chance of being stranded with a bad battery.