Can A Car Battery Overheat In Hot Weather?

Does hot weather has to do with dying our vehicle battery?

Winter is almost over, summer is just around the corner. I hear other drivers speak about car battery overheating because of the hot weather, and it made me wonder. Luckily, I have not had that kind of experience, yet I decided to investigate just the same just in case it’s true. I would not want to be caught unaware. What I found out was rather interesting. In this article, I’ll share with you what I’ve discovered.

Can a car battery overheat in hot weather? If you drive your car constantly and practice car battery maintenance religiously, hot weather won’t make your car battery overheat.

Effect Of The Hot Weather On A Car Battery

Batteries are designed to withstand all kinds of weather so, normally, it won’t overheat because of the hot weather. But when the temperature rises, it can bring about other problems.

The hot summer sun can cause the electrolyte in the battery to evaporate. This will not make your battery overheat, but the loss of fluids because of evaporation can harm the internal structure of the car battery that could lead to problems with overcharging.
Overcharging can shorten the life of your battery and make it less capable of delivering the capacity required to start your engine.

Internal corrosion is another adverse effect of extreme heat. Heat stimulates chemical activity. That is why 80°F is considered the perfect operating temperature for a battery.
When the outside temperature rises to around 90°F, the temperature under the hood will be approximately 200°F which, by any standard, is quite hot. The hot air under the hood helps the battery to perform well. But, when it becomes too hot, internal corrosion happens that causes irreversible harm and shortens the life of a car battery. (Click that link if you live in hot climate like Florida).

After a long hot summer, a battery’s capacity to maintain and store the amperage and voltage level is diminished. Even a well maintained car battery would lose capacity with time and usage. Extreme heat and cold accelerate the loss of capacity. After going through a sweltering summer, a battery’s tendency to fail will be more pronounced when winter comes around again. So, although a car battery usually fails during the cold season, the damage was really done by the heat of summer.

A battery used in extremely cold or hot weather won’t live longer than two to four years. However, a battery that has a higher lead content, such as a battery with a large cold cranking amp (CCA) could last much longer because of the extra lead. However, the added lead content of such a battery also increases its weight and price. And, having more lead is not a guarantee that it will not be adversely affected by extreme heat.

What Causes A Car Engine To Overheat?

Most cars manufactured in recent years have a cooling system that is liquid-based rather than air-based. This is the reason why overheating is most likely not caused by hot weather, but mainly due to the inadequacy of circulation inside the engine. Something in your cooling system is blocking the absorption, passage, or release of heat.

Here are some of the reasons why a car engine overheats:

1. A leaking cooling system

A leak somewhere in the cooling system is one of the principal reasons why your car overheats. It could be a leak in the water pump, radiator, head gasket, hoses, or thermostat housing. Any leak in the system will prevent the correct amount of coolant to reach the engine and properly cool it.

2. An obstruction in the hose

When the hose is clogged with dirt and debris from the road, the coolant flow is impeded resulting in a cooling system that does not function. The solution to this is to flush out the dirt and debris from the hoses and to fill the coolant anew.

3. Problems with the coolant

A coolant that is not the right coolant for your car will cause it to overheat, and so would a coolant-to-water ratio that is not accurate. These two issues on coolants could result in problems in maintaining the coolness of the engine.

4. An issue with the radiator

Usually, it’s not the radiator itself that is the problem when a car overheats but the radiator hoses that connect the radiator to the engine. When the radiator hose leaks or is clogged, the coolant can’t flow through to the engine, causing it to overheat. Radiator hoses are susceptible to wear and tear and should be replaced regularly.

5. A damaged thermostat

A damaged thermostat is another major cause of overheating. This device controls and determines how much coolant should circulate inside the radiator to maintain the right operating temperature of the engine. When the thermostat breaks down, the engine overheats fast.

6. Problems with the water pump

The water pump aid in the circulation of the coolant within the cooling system. Problems associated with the water pump such as a leak, a worn impeller vane, or displacement of the pump shaft can cause the engine to overheat.

7. Air within the cooling system

Air bubbles trapped in the cooling system hamper the flow of the coolant and lessen its effectiveness. The solution to such a situation is to bleed the cooling system to remove the air bubbles.

8. A radiator fan that isn’t working

Most cars of the latest models have electric fans to help draw air into the radiator to maintain coolness while driving at low speed or while idling. If your car overheats while idling, but did quite well while you were driving on the highway, the culprit for the overheating is most like a broken or defective radiator fan.

What Should You Do When Your Engine Overheats?

When you feel that your car is overheating or you notice the dashboard temperature gauge rising as you are driving, open the windows and shut off the air conditioning. The breeze will somehow relieve the strain on the engine and cool it off.

Another way to cool off an overheated car is by turning the heater on in the car when you observe that your engine is overheating. I know this sounds crazy, the last thing you need is more heat. However, the hot air from the car’s heater will drive out the hot air from the engine compartment so that the engine cools off.

It the car continues to overheat, pull over to the side where it will be safe, open the hood and allow the natural air to cool the engine.

These emergency measures will ease the condition momentarily, but, it will not exactly solve the problem. Have your engine checked by a trusted mechanic or technician the soonest time possible. Turning a blind eye to the problem could cost you a packet in terms of car repair in the near future.

How To Avoid Battery Damage From The Hot Climate

Your battery may not overheat, but it can surely sustain damage if exposed to the intense heat of the summer sun. To prevent your battery from being damaged by the heat, here are some things that you can do:

● Park your car in the shade whenever possible. Keep your car inside the garage or in a carport or park it under the shade of a tree to ensure that your car is protected from the heat of the sun during the day.
● Practice preventive maintenance by periodically checking the level of the battery cells’ electrolyte, and adding distilled water to it if needed.
● Inspect your battery for leaks, cracks, bulging, or any damage to the casing.
● Remove the corrosion (the greenish-whitish muck) that accumulates around the battery terminal and on top of the casing.
● Have your battery tested by an experienced mechanic, especially if it is already aging.

Take note, the life expectancy of your battery is from three to five years. With proper care and maintenance, it could last you longer than that. But it could also die prematurely if you don’t take care of it. A battery’s life depends on so many factors, and extreme weather condition is one such factor. Protecting your battery from exposure to too much heat could help prolong its life.


There is no danger of your car battery overheating in hot weather. Modern batteries are built to cope with all kinds of weather conditions. However, extreme heat can cause your battery problems of overcharging which in turn will damage it and shorten its life. So, it is still prudent to keep your battery protected from too much heat during the summer months to prevent it from being damaged.

A car overheats for so many reasons, but an overheated battery is not one such reason. If you experience overheating, there are emergency measures to remedy the problem immediately. But it is still best to have your car checked by your trusted mechanic who will know how to diagnose the problem and fix it.