How long does it take to charge a car battery and how do I charge it?

Has it ever happened to you that when you go to start your car to go to work, to the supermarket or to any event, it doesn’t start? Ah, the battery is discharged! so how do you keep it in optimal condition? And if it fails, how long does it take to charge a car battery, which is the best method of recharging it and what are the warning signs that the battery is running out?

What causes a battery to become discharged?

A battery is discharged by supplying electrical energy to the car’s engine and electrical consumers, and is recharged through the running alternator.

Wear and tear is accelerated when the alternator is deregulated or defective, in addition to the eventual evaporation of the water mixed in the electrolyte (increasing the concentration of acid and deteriorating the plates more quickly)

Excessive cold, on the other hand, decreases the performance of the battery and worsens its operation.

How long does it take to charge a dead battery?

To charge your car battery it is necessary to use chargers, which are devices that allow us to recover the electrical energy to our battery. These can allow a fast or slow charge, depending on the current used, the higher the current, the shorter the charging time and also depends on the condition of the battery.

There are different types of chargers that differ in their voltage and charging current ranges. So it depends on the voltage they provide to the batteries, the time it will take to charge them.

Another aspect to consider is the size of the battery, since the larger it is, the more amperage it has. This will also influence the charging time, because if I put the same amount of amperage in the charger and I have two different batteries, one with a higher amperage will need more time than one with a lower amperage.

With the fast charge you can decrease the time of charge in between 4 to 5 hours, although it is not very recommended, in some cases this fast charge is done when your battery is in good condition and it is left without charge because the lights were left on or the radio on, while the slow charge could take more than twelve hours and is recommended when the battery is at zero charge, or when you do not know the cause of the discharge of the same.

Why Maintain Your Batteries?

Batteries have the disadvantage that they suffer from self-discharge. When a vehicle is running a generator that keeps the battery charged, but when the vehicle is in storage or with little use, is the worst thing that can happen to a battery, especially lead acid batteries, because after a long time without receiving a charge will continue to discharge, this disrupts its normal operation causing sulfation and corrosion accumulation within them which reduces their life, running the risk that we have to replace them.

What to Keep in Mind When Buying a Car Battery Charger

Selecting the right battery charger depends on your needs. First you have to ask yourself if you need to fully recharge a dead battery or just keep the battery fully charged? To be clear about battery charging means that you need to completely recharge a dead battery, while battery maintenance requires a simple slow charge.

Most battery chargers perform both functions, but understanding their limits and the amount of time to recharge depends on the size of the battery and the vehicle. So you should take into account the following parameters to choose the right charger for you:

  • Voltage: You only need to know the voltage at which your battery works. Almost all cars operate with a 12V system. Unless you are looking for a multi-functional charger that not only charges your car battery, but also your utility vehicle, the charger you choose should have 6V power.
  • Amperage: The higher the amperage, the faster the battery will charge. But charging the battery quickly is not always good. In this case I recommend a battery charger with automatic voltage and amperage detection (smart charger). This way you don’t have to mess with the settings. Just plug it in and you’re done.
  • Battery Type: Although most chargers today are capable of charging almost any type of battery, it is important that you make sure you know what type of battery your car has so that you can get the right charger for you.
  • Size and weight: This will depend on how much space you have for your charger. Usually, they weigh less than 1 kg, although you can find less portable models that can weigh more than 7 kg. I recommend a small, lightweight model that is easy to keep in your trunk.
  • Safety: The portable car battery charger you choose should have safety features that can help prevent damage to the battery, protection against short circuits, reverse polarity, overcharging and overheating.

How long to charge a car battery

This will depend on many factors such as the capacity and percentage of discharge the battery has. Another important piece of information is the charging speed measured in amps (A) delivered by the charger at the output.

How long does it take to charge a car battery with a 12 volt charger?

Typically, vehicle batteries have 40 amps, so it would take about 12 hours to fully charge them with a 12-volt charger. For an electric vehicle, this would take about 30 minutes to charge to 80% of its capacity.

How to connect a car battery charger

The first thing that must be identified when connecting a charger is the polarity of the cables that will be connected to the battery. They are usually identified by the color red on the positive (+) and black on the negative (-). Once detected, they are connected to the poles with the same symbol located on the battery.

How to Use a Car Battery Charger

Although today the different applications and features of many battery chargers can make them more difficult to use, the general process for setting up a car battery charger is always the same:

  • First make sure to remove the negative battery cable from the negative terminal and then remove the positive battery cable from the positive terminal.
  • Make sure your charger is not plugged into an outlet and that the power switch (if applicable) is in the off position.
  • Connect the positive charger cable to the positive terminal.
  • Connect the negative charger cable to the negative terminal.
  • Turn on your charger and mark the appropriate setting (if applicable).
  • Check the charger frequently throughout the charging process to ensure that there are no problems.
  • Do not touch or move any of the charger cables while the charger is in operation.
  • Turn off the charger and unplug it before removing the charger cables from the battery.
  • Disconnect the negative charge cable first.
  • Disconnect the positive charge cable.
  • Reconnect the positive battery cable.
  • Reconnect the negative battery cable.