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Dead car battery. How to maintain the car battery

17 October 2022

A dead car battery is the most common issue that occurs in winter. Freezing temperatures cause many difficulties in starting the car in the morning. However, many drivers don’t know that the issues with starting the car caused by the lack of electricity might also happen in summer. What could be the possible reasons for that?


What exactly is the car battery?

The car battery is a device which provides power necessary to start the engine. It’s also necessary for using other subassemblies when the engine isn’t on. It’s a source of power in the form of constant current – the battery itself dose not produce it. It’s only used for storing the current in the form of chemical energy. The most commonly used batteries are lead-acid. The principle of their operation is based on the primary cells created from the lead electrode, the lead dioxide electrode, and the aqueous sulfuring acid. It’s worth keeping in mind that the electricity stored in the battery and used during stopovers and engine start-ups is consumed. To recharge it, the alternator is needed – a device which “produces” new energy while driving.



The alternator is usually placed under the hood – it’s placed in a special base. It’s important that it’s installed properly, so that it’s well stable.



Why does the car battery discharge?

There are many reasons for which the car battery discharges. Keep in mind that not all of them require replacing it. Often, all you need to do is to recharge the battery yourself in your home workshop, or check the battery performance, and most often you won’t need a new battery. Among the most common reasons why the battery discharges there are:

  • leaving the car at a stopover, with the energy consumption sources on,
  • incorrect battery and car model fit,
  • battery pollution,
  • incorrect alternator work.


How to correctly recharge a dead car battery?

Every car owner should know how to correctly recharge the car battery. The recharging process is not the only important thing, the equipment used is equally crucial – everything impacts the battery service life. When the battery is discharged for a long time, sulfation might occur, which has a negative impact on the device. For this reason, it’s good to recharge the battery as soon as possible.

It’s incorrect to start-up the car with the use of the booster cables and only then charging the battery. The best way to do it is to replenish energy with the use of a good quality battery charger. A proper device allows not only regulating the voltage, but also it automatically turns off after recharging the battery. The process of recharging the battery should include:

  • unplugging the battery – you should unplug the negative terminal, and then the positive one,
  • thoroughly clean the terminals and poles, preferably using sandpaper,
  • connect the battery charger – you just need to connect the crocodile clips to the charger poles.

After finishing these steps, leave the battery for a few or several hours to recharge. In the case of older battery chargers, it’s to check from time to time the full recharge moment.



When should you not recharge the car battery?

Car owners should also know that the battery can be recharged only in certain conditions. Correct connection of the battery charger to the poles is not the only important thing. You should not recharge a battery which is:

  • kept in the freeze,
  • charged
  • damaged,
  • leaking the electrolyte,
  • leaking anything,
  • rusty,
  • dirty.



Recharging a battery with at least one of these characteristics not only is dangerous, but also might have a negative impact on the device.


Dead car battery – first signs

 The signs of a dead car battery are quite obvious. When the energy runs out, it’s impossible to start-up the engine – there’s no ignition, although the starter is working. All the other subassemblies are also not working – such as the radio, but also the dashboard lights are off.


Discharging to “zero”

When the battery discharges, the driver has de facto two options. The first one, the fastest, is starting-up the vehicle with the use of the booster cables and another car with a working battery. Then, you should:

  • prepare the booster cables,
  • park the other car near the vehicle with the dead battery,
  • connect the booster cables – the red one to the positive terminal, and the black one to the negative terminal. It’s important to connect the cables to the charged battery first, and then to the dead one. Moreover, remember to connect the black booster cable to the grounding next to the terminal,
  • start-up the vehicle with the charged battery and wait a few minutes,
  • start-up the vehicle whose battery is being charged and leave it on for around 20 minutes.



The second solution is connecting the battery to the battery charger  then, the charging lasts several hours.


How to check whether the battery is dead?

When the driver, after igniting the car, has difficulties starting-up the vehicle, and the dashboard lights are off, then it’s most probable that the car battery is discharged. The easiest way to check if your car battery is dead is using the voltage meter. The correct values are between 12.6 and 12.8 V. If the meter readings show correct values, then wrongly tightened or dirty terminals might be the problem.


Dead car battery in winter

Every driver knows that in winter low temperatures might lead to discharging the battery. Generally, they are accompanied by bad weather, e.g. intense snowfall – you use more often lights, wipers, heating, heated seats, or defrosting the rear window and the windscreen, so the energy from the battery is in greater use. However, in winter, drivers are hardwired that the battery might not last long, so they try not to exploit it too much. In summer, it’s a different thing.

Going for a long summer trip, you turn the air conditioning on full, and, in addition, other devices are plugged in, such as the GPS navigation, a travel refrigerator, and one of the passengers charges their tablet or a smartphone. So, the battery is much more exploited in summer than in winter. What’s more, after reaching your summer holiday destination, drivers usually leave their car in a hot parking lot for days. It often happens that after such a long standstill, it’s impossible to start-up the car. Why does it happen? In temperatures around 30 degree Celsius, the battery discharges approximately twice as fast as in the optimal temperature for it – 20 degree Celsius. Each time the temperature increases by 10 degrees, the average pace of the battery discharging doubles. So, taking care of the battery in summer is equally important as in winter.

One might say that winter is even better for the car battery. The car fails to start-up usually in front of your house. At homme or in your garage, you usually have a battery charger, and if not, then you can definitely find a friendly neighbour who can lend you booster cables. As the last resort, you can always call a taxi whose drive will either help you start-up your car with the booster cables (most taxi companies provides such services) or will give a ride to your destination. Often, you can also get help through assistance from your insurance or additional assistance, which you have obtained when purchasing a battery of a renowned brand. In summer, if you’re spending your holidays abroad, you can’t use most of these options. An additional difficulty is the language barrier, especially in the popular for Poles countries, like Romania, Bulgaria, Croatia, Montenegro and Albania. Instead of making the scenario of having a dead battery during your holidays come true, it’s better to get well prepared for the trip beforehand.


How to maintain a car battery in summer?

As always, prevention is key. Before a long trip, check the technical condition of your battery in a professional workshop. The voltage of a charged battery should be 12.6-12.8 V. If the measurement shows 12.4 V, then your battery is most probably dead. It’s also good to check the current leakage, which is the amount of electricity charged for maintaining the computer or the radio memory, or the alarm, when the engine is off. The current leakage should not exceed 50 mA (0.05 A). Also, check if the battery is dry and clean, whether it’s correctly installed in the designated place, and if the terminals are clean, and the clamps are correctly fixed and covered with acid-free petroleum jelly.

So why is it a good idea to have these things checked by a professional when some you could just check yourself? Sometimes, when unplugging the battery from the car, it’s necessary to connect it immediately to another power source. A longer power cut might lead to serious consequences in maintaining the electronic circuits. Some batteries also require to have their wires plugged out an plugged in in a specific order. If you don’t know the requirements of these procedures for your car and the battery, it’s better to let a professional do it for you instead.

Another important activity to do, when you don’t have a maintenance-free battery, is observing the electrolyte level. The markings placed on the battery show the minimal and the maximal level of the electrolyte. If you see that the level is low, refill it using only the distilled water. Don’t use any acids or ordinary water! The necessity to refill the electrolyte in summer is connected to the fact that in high temperatures, water from the electrolyte evaporates fast, which increases its acidity, the sulfation of the battery cells, and finally partial or complete loss of its usability.

Before going for trip by car, don’t forget to pack the battery charger of the right power with you. Whereas while driving, remember to use only those electric devices which are actually necessary. Don’t leave power consuming devices on while the engine is off.

When you follow these rules, you can be sure that the battery will work well in summer and throughout the whole year. Using it properly and maintaining it well in the warm months will result in it’s proper work, not only in summer, but also in winter.


How to extend the service life of the car battery?

If you want to extend the service life of your battery, you should never let it discharge completely. In case of difficulties with starting-up the car, check the battery condition. In addition, during stopovers, it’s good to turn off all the unnecessary power consuming devices. It’s also helpful to control the electrolyte level in the older models, as it’s incorrect amount also negatively impacts the condition of the device. Another necessary thing to do is regularly cleaning the terminals and clamps, as it’s the only way to ensure correct current flow. Also, you shouldn’t overcharge the battery, as this might lead to its permanent damage.


It is good to know

Did you like this article? Anything you’d like to ask in your comment? Feel free to share your feedback and comment at the bottom of the article. And remember – always before buying a car, motorcycle or even a trailer – check vehicle history with autoDNA based on the VIN numberVIN check is one of the most important things to do before deciding to buy a used vehicle. Thanks to this, autoDNA helps you make an informed decision.



Dead car battery. How to maintain the car battery
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Dead car battery. How to maintain the car battery
A dead car battery is the most common issue that occurs in winter. What could be the possible reasons for that?
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