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

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October 22, 2020
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A flat battery is one of the most common causes for cars not starting so how do you keep it in tip top condition, and if it does let you down, 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 your battery is on its way out?

charge a car battery

What causes a battery to go flat?

A flat battery can be caused by a number of things, such as lights being left on, something in the electrical system causing a battery drain, or even a faulty battery that won’t hold its charge. Corrosion and cold weather and general wear and tear can also cause your battery to fail meaning it could be time to buy a new one, or inject new life into the old one.

Is it better to charge the battery or jump start the car?

In the long run it’s better to recharge the battery, but in emergencies a jump start may just do the job. 

When you jump start a car you boost the engine’s failing battery with a second battery, usually on another car. You connect the jump leads to the two battery terminals positive to positive and negative to negative. 

Then, with the booster car’s engine running at a fast tick over you allow the failing battery to take a little boost charge and the car should be able to start. Then, as you run the engine, the battery should begin to recharge itself.

How long does it take to charge a dead battery?

It can take between an hour and a day to charge a flat car battery depending on what type of battery your car has, and the mode of charging you choose.

Which battery charger do I need?

There are three types of battery chargers: linear chargers, multi-stage chargers and trickle chargers. 

 What is a linear battery charger?

The linear battery charger is the simplest charger you can get. It enables you to recharge your car’s battery via the plug-in at a wall socket. 

It requires little set-up and power but the charger operates at a low amperage meaning it can take a long time to charge your battery and, depending on the amperage, it could take up to 12 hours to fully charge the battery. 

The linear battery charger runs at a continuous charge, and doesn’t have a controller to stop the charging when the battery is at full power so there is always a danger that you may overcharge your battery and damage it. 

What is a multi-stage charger?

 The multi-stage battery charger works in bursts of power instead of a continuous charge. This is better for the battery cells, and prevents long-term damage that can be done by the linear batteries during the continuous charging.

 The multi-stage chargers work much quicker than the linear charger. A top of the ranger multi-stage charger could recharge you car battery in as little as an hour. 

charge a car battery

What is a trickle charger? 

Trickle chargers operate between 0.8 and 4 amps. They run at a low power output level and are not meant for charging a battery when it goes dead. However, they are useful in preventing the problem if you connect it to the battery when the vehicle isn’t being used.

Classic car owners often leave their car batteries on trickle charge while the vehicle is laid-up over winter. Read our full list of classic car care maintenance tips.

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

 Car batteries usually hold 48 amps, so it will take about 12 hours to reach a full charge using a 12 volt charger. It takes around 30 minutes for an electric vehicle to charge to 80%.

 Do car batteries charge while idling?

 The length of time it takes to recharge your car battery while the engine is running depends on whether the car is idling or you are actually driving, the car usage cycle, what electronic instruments you are using and initial charge time.

The best way to recharge your battery is by letting the car idle with all other electrical items — radio, heated rear window, air conditioning, lights, etc — turned off. 

How long does a car have to run to charge a dead battery?

 The length of time you need to run the car to recharge a dead battery depends on the condition of the battery, the performance of the alternator and which electrical instruments you are using.

 If the battery is not faulty and the car is in good working order you need only drive for half an hour or so to give your battery an adequate charge.

 Can a completely dead battery be recharged?

 If the battery is your only problem and the car is in otherwise good working order, it is quite possible to completely recharge a completely dead battery.

 Using the charger or a jump start or push start and then letting the engine idle with electrical items switched off. 

 Is it OK to charge a car battery while still connected?

It is quite safe to charge the battery while the terminals are still connected. However, if your car isn’t garaged while you’re recharging, it may be more practical to disconnect it and recharge it in a safe place within the home.

That negates the need to have electric cables running outside your home. 

charge a car battery

 Charging a car battery — 4 things to remember

  1.  Charging a regular car battery with a typical charge amp of around 4-8 amperes will take about 10-24 hours to charge it fully. 
  2. To boost your battery enough to be able to start the engine, it would take around 2-4 hours.
  3. The best way to maintain a long life for your car battery is by recharging it slowly.
  4. It is possible to recharge your battery more rapidly, but this may damage its long term performance.

A battery can let you down any time, Adrian Flux won’t

Contact Adrian Flux for all your motor insurance needs. The best deals do not appear on price comparison sites and are usually only available over the phone so call 0800 369 8590 to find out how much you could save. 

 

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