charging car battery

How Long Does it Take to Charge a DEAD Car Battery?

In Electric by Magnus Sellén26 Comments

You are on your way to your work and are in a hurry and jumping into your car and trying to start it – Nothing happens –

The car battery is drained. You have a car battery charger in your garage, but how long time will it take to charge your dead car battery?

Charging a car battery is not always as easy as it sounds; there are several tricks out there to save your battery and give it a longer lifetime!

In this article, you will get all the answers you want for this question, and a bit more!

How long does it take to charge a dead car battery?

It takes between 4 to 24 hours to fully charge a totally dead car battery, depending on how many Amperes your car battery charger is charging with and the size of your car battery.

The most common rate for car battery chargers is around four amps. To fully charge a battery of the size 52Ah would take about 10 hours from dead to fully loaded, but you would probably be able to start your car within 1 hour.

First, you have to take a look at your car battery charger to find out how much ampere it’s giving out. High amperes charge your car battery faster. Low ampere is better for maintenance charging of your battery over long periods.

You do also have to take a look at the size of your car battery and the battery type. Usually, a mid-sized car uses a battery of the size 40-80Ah. You also have to take in mind of the kind of car battery. An AGM/GEL battery can charge up a bit faster than a regular wet battery.

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If you charge your car battery with 40 amps it will be fully charged real quick, but can it damage my battery? Take a look at the next chapter, and we will figure it out!

How quickly should I charge my car battery?


The speed of your car battery charging should depend on what you want to acquire. Fast charging can damage your battery and will make the life shorter of it. Long-time charging with low amps is the best for keeping the battery’s lifetime long.

Usually, a standard car battery charger is giving out 4-15 amperes. 2-4 ampere is typical for a maintenance charging, and it will take around 24 hours to charge a dead battery at this load fully. Check your car battery for any settings for the charging rate and apply the charging rate for your needs.

If you want to charge your car battery quickly, without damaging your car battery, I would recommend charging your battery at the rate of 8-15 amperes. Charging your battery over 15 amperes can damage your battery if you are unlucky and will make the lifetime shorter .

Jump starting

If you want to start your car quickly, I would recommend using a Jump Starter instead. They will start up your car within seconds and are a lot more user-friendly than the old style jumper cables. Jumper cables can be connected wrongly and cause severe damage to your car’s electric system. Modern jump starters are often wrong-polarity secured and will not give that many sparks (Fire-friendly).

What car battery charger should I use?

First, you have to find out what car battery charger you should use to see what amp rates you want for your charger. Modern chargers are easy to connect and have a battery charging monitoring which will regulate the amps itself. But you should check anyway to see how many amps it’s charging.

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Cheaper chargers do often promise more amps than they charge with. In my opinion, it’s better to choose a quality charger which gives lower amps instead. It will save your car battery, and it will minimize the risk of damage to your vehicle.

A car battery charger that I really can recommend are the CTEK chargers. You can find them here on our list “Best Car Battery Chargers.” They have several sizes of their chargers for your needs, and it’s a well-known brand that is probably making the best car battery chargers on the market.


  • Charging a mid-sized car battery with a typical charge amp of around 4-8 amperes will take about 10-24 hours to charge it fully. To charge your battery to be able to start your car, it would take around 2-4 hours.
  • Charging the car battery slowly is the best way to maintain a long life for your car battery
  • You can charge your car battery fast, but it may cause damage to your car battery.

If you have any other questions about car batteries, you are welcome to comment down below, and I will answer all your questions as fast as possible. If you have any other car questions, you are welcome to ask them at our homepage.

26 thoughts on “ How Long Does it Take to Charge a DEAD Car Battery? ”

  1. Hi there
    I have a 2009 Fiat Punto 1.9 in a 2 litre. The car has been standing for a very ling time and the battery is totally flat.
    I have a Battery Carger 4 AMP 12/230 VOLT.
    Can I use this Charger? I’m scared that the charger is not strong enough and will damage the battery

    1. Author


      It’s not a problem to charge it with a charger that is charging it slowly, it’s actually better than a fast charger in these situations. However make sure that you are connecting the positive and negative clamp on the right connectors when the battery is flat!

    2. I have 2006 Cadillac the battery has been dead for about 6mos or more practically new. Can it be charged up while still in the car?

    3. Hi Magnus, My own question is about the device amidst the exhaust system in the form of honey comb shape, quite real that it lessens the noise of the exhaust system while working, but , does it really reduce the fuel consumption of the car?

    4. Hello ,

      I drive a Toyota Corola 2002, I haven’t driven it for a month and half. When I tried to start the car. It wouldnt start neither was there any sound heard. I called in a mechanic who did a jump start left it to run for only 15mins, and put off the engine.
      I tried afterwards to start the car but still wouldn’t start. I figured out the battery was dead. I called him again ,and he told me it will take 3days for have a fully charged battery. Is this true?

  2. I want to recharge a varta E11 battery but there is no way to get to the distilled water caps to unplug them. Would it be dangerous to go ahead and charge anyway?

  3. Can i charge another battery using a jumper to my car with engine working connecting to my car batttery

    1. I am charging a larger than normal 2003 Mercedes 100A battery for the second time with a 5A Ring smart charger. The 1st charge was a year ago and it took 4-5 days from dead. Tha car travelled 250 miles in 12 months and is dead again. No surprise. It has been charging for 60 hours and the charger is indicating that the process is over half way. My garage tested the battery 9 months ago and said it is in good condition. My question is: Is this reasonable given that 5A is only a max applied for only part of the process?

      1. I have a 8Amo charger , how long does it take to charge a 12 volt battery

  4. Hello, my car battery just died for reasons I do not know of and I am currently about to charge it. When it is charged, what are the chances the battery would go dead again? Do I have to drive the car everyday? I am asking because I use my car only twice a week. Also the battery in question was newly bought in March. Thank you

    1. Charge it. No need to spend money. Charge it ans drive it atleast 10 miles. And start leave it for 10 mins every 10day.

  5. How long a recharged battery lasts? Is it worth charging or just buy a new one? I don’t want to got stuck in the middle of nowhere with a dead battrry…thanks.

    1. It should last for more than 10days idle. But make sure its fluid is full. In case its dry then no need for fluid. Start the car after 10 days and leave it running for like 10 mins. Stay in peace.

  6. I will take vacation for three weeks . So nobody will start my car . My question is , is it ok that my car will not start or used for three weeks. What will happen to my car then

    1. Unhook battery terminals. Reconnect when u return. It will still. Be able to start car.

  7. Hi there!

    Just being a random guy from Sweden, with cold winters and Polar bears on the streets and all that, I would suggest y’all just getting a CTEK MXS 5 charger (yeah, they are a bit expensive but hey, quality has it’s price!) and then mount the quick-connect eyelets, included, to your battery. Whenever you’re not using your car then just attach the charger and it will charge the battery until full and then automatically switch to maintenance mode. Totally hassle-free and well worth its money, especially on the day you would have been standing there with a flat battery.

    Sure, if the battery is totally dead it takes its time to charge but using it regularly will save the battery and the charge time will be shorter.

  8. Hello, is it better to take my car to tire plus to charge my car battery complely?, thank you.

  9. Will I be able to run a 3kw BLDC motor with a battery and recharge the battery with an alternator

  10. My explorer battery was dead last week and i took it 2 have it checked and they said it was a bad battery so i got a new one and now i tried 2 start my suv n its a week later and the car only unlocked the doors n nothing else so the battery is dead again. I am charging it and im not sure how long i need 2 charge it 4 and what the problem might be.

  11. If I’m charging a battery thats half in the yellow using a 10 w how long would it take to start it?

  12. I have an ‘05 Mercury Mariner that was in a recent fender bender. Had a new radiator installed and drove it around town no problems. But then it has sat for a few days. Last 2 days the battery is dead. Could it be from not having driven it much so the charge is gone? I cleaned the terminals and the posts. It’s on a charger now. How long will it take to charge and do you think it could be something else? I also live on the desert and rodents are a pain in the ass. Thanks for your input.

  13. Do I have to drive my car right after I charged it? Or can I Waite til the next day to drive it?

  14. Sorry for random question on fbook.

    If you are familiar with the batteries can you tell me a battery charger controller which will cut off the charging power source to avoid the battery to be overcharged.

    They told me that overchaging the battery is not good and I am not going to wait 10-20 hrs for my battery to be full charged.

    I may even charge it overnight which means I cannot monitor the charging percentage.


  15. My battery is my battery is fully charged and it will start the car the same day however when I start my car the next day it will not start what is a problem

  16. M y 2007 Seat Ibiza has been stood for 3 weeks. It is a sealed battery and the battery indicator is black. Is it dead or can I trickle charge? I have a battery charger with ‘start/boost’ option but this needs two people according to charger manual. (One to turn key, one to press switch to starter/boost).Thank you in advance

  17. I haven’t AC Delco professional gold battery in my 2003 GMC Sierra that only has 87,000 miles. My question is what is the best ctek battery charger for this battery. I seldom drive the truck, sometimes leave it in the garage for the winter and it still starts after the winter. I recently went out to started after it hasn’t been run for about a month and it was dead so rather than use jumper cablesc is there ctek charger you would recommend? I’m looking for the best quality and easiest to operate charger. Thank you

  18. Due to very high demand and a high amount of comments, you might have trouble getting your comment answered by me. If you want to get fast answers from a certified automotive technician you should ask your questions here: Ask A Mechanic

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