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How To Charge A Car Battery Without A Charger?

The biggest fear of a car owner comes true when he finds out that his car battery has run out of its charge. If you are driving your car regularly, you are likely to get a warning on the dashboard when your battery has a low charge remaining.

However, you might not have noticed it or ignored it or you might not have started your car for days. There are various reasons why your car battery either has no charge or low charge . You may not have a car battery charger readily available, and hence, you should know how to charge a car battery without a charger.

Before You Charge A Battery Without A Charger –

It is important to you to note that the best way to charge a car battery is with a charger only. This is because a charge is designed to charge a car battery in the most effective and technically correct way. Therefore, whenever a charger is available, you should not try out any other method. Before trying out any of the following methods to charge a battery without a charger, you should have the following items in possession.

  • Sturdy and protective gloves.
  • Protective eyewear.
  • Wire brush for cleaning.
  • Wire probes with clips.

You should have them in your car because you may need them for anything you need to charge your battery safely.

Method 1 – Use Jump Leads

When your car battery is dead, you have to jump-start it so that you can at least start the engine. Once you start the engine, you can go to your destination, and you can charge your car there with a proper charger. To jump-start your car, you will need to connect the jump leads from another vehicle to your car battery.

The jump leads can help you charge your car battery just enough to start your car engine. However, if there is an issue with your car battery, jump leads won’t help in such a scenario. It is very important to read your car battery manual to be sure how to connect the jump leads properly. Otherwise, it could damage your car battery. Here are some important steps to follow.

  • Use a wire brush and clean the battery terminals so that there is no dirt, rust, or corrosion issue with them. This is important before you connect the jump leads so that the charging is proper.
  • The jump leads should not be more than 6 gauge so that the current can flow steadily and safely.
  • The donor car’s engine must be running for at least 10 minutes with the jump leads connected to your car so that there is enough charge on your battery to start your car engine.

Method 2 – Use Solar Panel and Solar Charger

If you have a solar panel installed at your home, you can charge your car battery easily. However, it is not very effective when your battery is dead because it will take hours for the battery to get charged to even get started. You should have some knowledge about compatibility before connecting your solar panel to your car battery. Using a solar charge controller is the best way to connect the solar panel to a car battery for charging it up.

A solar charge controller prevents your car battery from getting over-charged. Overcharging can damage a car battery and lower its lifespan. In fact, a controller can prevent reverse current flow.  You can also charge your car battery with a solar battery charger and it is the safest way when you are charging from a solar source.  It will naturally prevent overcharging and reverse current. If you are buying a solar charger, make sure you take the size of the car battery so that charging time is optimal. A 100W solar charger can charge a car battery in approximately 8 hours.

Method 3 – Use UPS Inverter

In today’s world, every home has a home UPS inverter to get power supply from the home inverter battery when there is a power cut. An inverter generally converts the DC power of the battery to the AC power of electricity. A home inverter battery is generally a 12V battery which is equivalent to a car battery.

Hence, you can use it to charge your car battery, but you should check the manual to ensure that the inverter and its battery are suitable for charging a car battery of equivalent capacity. In fact, most inverters have displays to check charging progress and prevent overcharging and reverse current.

Method 4 – Charge Battery By Putting It Into Another Vehicle

If you are not very confident about jump leads and charging from a solar panel and UPS inverter, the easiest option you have is putting your battery into another vehicle’s battery spot to charge it. This is only applicable when you have another vehicle where the battery is similar to the battery you want to charge. If you are not sure that the batteries are similar in size and shape and even in specifications, you should avoid connecting them to another vehicle.

Otherwise, it could damage the battery as well as the internal parts of the other vehicle. Specifically, you should match the mAh of the battery. Attach the battery and turn on the engine on the other vehicle and if it is not working, do not force it or be stubborn about it.

Method 5 – Use A Car Jump Starter

Every car owner should have a jump starter in their car so that it can save them in case their car battery goes completely dead. It will charge the battery just enough to get the engine started. Once the engine starts, you can use an alternator to charge the battery.

If you cannot jump start with a starter, it is probably because your car battery is faulty. However, you should disconnect all additional connections to lights, multimedia system, and air conditioner before jump-starting. Moreover, clean the terminals before connecting with a wire brush.

Method 6 – Use A Battery Isolator

Last but not least, a battery isolator is useful in charging a secondary battery by driving charge from the alternator of the primary battery. It is not the most effective way, and it can get the job done. If the battery is totally dead, it could be tough, but it is worth giving a try. The alternator first charges the primary battery and then supplies it to the battery isolator to charge the secondary battery. A battery isolator is quite common for RV and campsites.


You need to charge your battery on the spot when your battery is running on low charge as well as when it is completely dead. You may not always have a battery charger with you, and hence, you should know all the ways to charge your car battery without a charger. We have stated all the different methods, and you can choose any one as per suitability.

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