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2 Ways to Charge a Car Battery without a Charger

We’ve all had to use a car battery charger to charge the battery of our cars. But this isn’t always the case and the real challenge is to charge the battery without a charger. It might seem impossible to you, but it is possible! In this article, we are going to shed some light on this matter.

Most people are aware of the fact that a car battery is continuously charged by the built-in electrical system of the automobile. There is no point in taking the battery out for some other objectives.

However, you might sometimes need your car battery outside of your car for some reasons. No doubt that the best and most effective way is to use a charging device because it is pretty effortless.

Yet, there are some other techniques too by which one can charge the battery of one’s car without having a charger. You can recharge the battery of your car by following the simple steps discussed in this article.

Tools required to charge a car battery without a charger:

  • Power source unit (use a laptop battery if you have nothing else)
  • Multimeter or ammeter
  • Safety gloves (optional)
  • Safety glasses (optional)
  • A charged cell phone (just in the case nothing works out for you)

Method 1 – Using a power source and wire probes

  1. First of all, you need a power supply. For the slow charging process of the car battery, there should be a power supply in any form. Think about all the things that you have around you if you do not have a power supply. Any other battery that has the same voltage rating as the battery your car does will work too. Make sure that you use a reliable power source. The dead battery will generate charging hindrances otherwise.
  2. Check out the output power of the power source with the help of your wire probes. Attest the current rating and the voltage rating. With these probes, also check out the voltage rating of the battery of your car. After taking these values into your knowledge, you will have a rough idea that how much time the whole charging process will take.
  3. Place the car battery and the power source at a certain distance from one another. This distance is kept for the safe charging of the components of your car battery. If you do not keep enough spacing, a spark can be generated between the car battery and the power source.
  4. Now, connect the light bulbs between the car battery and the power source. These light bulbs will give you an idea that the electric current is flowing or not. You can also use an ammeter or a multimeter but that would be a bit difficult to use as you might be busy operating on other things in the circuit.
  5. After checking the current flow, you are now all set to connect the car battery, the power source, and the light bulbs in a circuit. It is necessary to put this setup in a region that is away from residence. It is one of the key parts of ensuring safety.
  6. Now, connect the negative terminal of the wire probes to the power source first. Similarly, connect the other negative terminal of the wire probes to the battery of your car. Do this procedure with the positive terminals as well. The power should be running at this point.
  7. Note that you will only be dropping the power with the help of this created setup. The battery of your car may only obtain a few volts after ten to twenty minutes of the charging process.
  8. Meanwhile, you can confirm the progress of the charging procedure with the help of a multimeter or an ammeter connected to the terminals of your car battery.
  9. The light bulbs should be lightened up with just a slight heat generated during this process of charging. If they get overly warm, there is too much power flowing towards the car battery. Immediately disconnect the setup and troubleshoot it.
  10. After about half an hour is passed, get rid of the power from the car battery by detaching the negative terminal first and the positive terminal later. At this stage, you can also seek help from the multimeter to confirm the voltage of the battery without the load.
  11. It is not compulsory to charge the car battery up to twelve volts (if the voltage rating of your car battery is twelve volts) because you may end up overcharging your car battery and it can cause troubles. So, it is advisable to charge the battery to a half-done state to avoid any harm to the car battery or yourself.

Method 2 – Using the battery of a laptop

  1. Take out two wires from the battery of the laptop. One will be used for the positive terminal and the other one will be used for the negative terminal.
  2. Note that the positive wire is inside and the negative one is outside of the battery.
  3. Now, attach the negative wire with the negative terminal of the car battery.
  4. Connect the bulb in the distance between the two devices to ensure the current flow.
  5. After charging for thirty minutes, drive your car at normal speed. It will work out.

You can also jumpstart your car with another car if you are in the middle of a road. It will also charge your car battery if you do not have access to your charger.


These methods are pretty reasonable ways to charge your car battery without a car charger. Always make sure to wear proper safety tools and take precautionary measures.

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