How To Charge A 12V Car Battery Without A Charger?

I recently faced a situation where my car battery was discharged, and no other cars were available to jumpstart. I found some easy workarounds to charge my car battery without a charger.

I decided to share those methods by which you can charge a 12-volt car battery without a charger. If you ever find yourself in a situation where your car or motorcycle is not starting because of a low battery, follow these methods to recharge the battery.

How To Charge A 12V Car Battery At Home?

I want to inform you that the best way to charge a battery is with specified chargers only. However, these methods are recommended only if you don’t have a car battery charger.

1- Use Home Inverter

Home Inverter

The easiest method to charge a 12-volt battery is by using a home inverter. If you have an inverter generator at home for power backup, you can recharge any 12-volt battery.

Home inverters generate 13.6 volts of DC current, which is a perfect voltage for charging a 12-volt car or motorcycle battery. I also recharged my car battery with an inverter that converts AC current into DC.

Follow these steps to recharge a 12V battery with a home inverter:

Step 1: Disconnect the positive terminal of your car battery and unscrew the wire attached to it. After disconnecting the positive terminal, disconnect the negative terminal.

Step 2: Remove the battery from the cabinet by unscrewing all necessary fastenings from your car.

Step 3: Power off your home inverter switch and place the car battery near your inverter.

Step 4: Connect the Red wire (+) to the battery’s positive terminal, followed by the Black wire (-) to the negative terminal.

Step 5: Turn on the inverter switch, wait for 20 to 30 minutes, and then turn off the switch again and disconnect the battery.

That’s it! Your car battery will be sufficiently charged in 30 minutes. Now, you can install the battery in your car and connect the wires.

2- Use Solar Panel Charger

Solar Panel Charger

If you’ve installed a solar panel on your premise, you can recharge your motorcycle or car battery with that. The current output from a solar panel charger is 13.6 to 14.1 volts, which is appropriate for charging a 12-volt battery.

Follow all the steps mentioned for charging a 12V battery with a home inverter but let it be connected for at least 60 to 90 minutes (depending upon the capacity of your solar panel). A 200W solar panel takes approximately 3 to 4 hours to recharge a car battery fully.

3- Use Jumper Cable

Car Jumper Cable

If you’ve another car, tractor, motorcycle, or another vehicle at home, you can use a jumper cable to recharge a 12V dead battery. The process of recharging a car battery with another car is pretty simple.

Follow these steps to charge any 12V battery with jumper leads:

Step 1: If your battery is installed in your car, then turn off the ignition key and disconnect the main fuse from your car fuse box to cut off the power supply to other electrical accessories.

I recommend removing the main fuse because there are chances of electrical failures (lights and other electronics) due to a surge in voltage. It also increases the battery charging speed.

Step 2: Open the bonnet of the donor car, put it into neutral gear, and start the engine. Now, connect the Red wire (+) to the positive terminals of both batteries (Donor & Recipient cars), followed by the Black wire (-) to the negative terminals.

While making the connection, ensure that the Red (+) and Black (-) wires don’t touch each other, else electric spark will be generated, and the battery will be discharged.

Step 3: Once you connect both jumper wires tightly, press the donor car accelerator paddle to increase the engine’s RPM.

If your battery is fully discharged, keep the engine RPM at a higher speed for 2 to 3 minutes to revive the dead battery.

Leave the car idling for another 15 to 20 minutes and disconnect the jumper leads. Your battery should be sufficiently charged to crank the engine.

4- Use Desktop Power Supply

Charge 12V Battery With PC Power Supply

The current output from the desktop power supply is generally 12V, and you can use it to recharge your car battery in an emergency.

But, before going for this method, read the output voltage of your desktop power supply. If the rated current is at 12V or higher, then only use this method to recharge your car battery.

Charging 12V Battery With Laptop Charger
Image Credit: Team-BHP

Also, If you have a spare laptop charger at home, you can recharge a 12V car battery. The power output from laptop chargers is generally 14.6V to 19V. (A member of Team-BHP has experimented with this method)

Note: It’s recommended to charge Lead-Acid batteries at 13.6V to 14.2V DC current supply, but the laptop charger’s power output is 19V. So, it’s advisable not to leave the battery connected for longer; otherwise, your battery will be damaged due to overcharging.

5. Jumpstart Your Car

Car Jump Start

If your car battery is discharged, then you can jumpstart your car engine with the help of another car or motorcycle. Once your car engine is started, drive a few miles at high speed to recharge the battery.

Conclusion

These are some easy methods to charge a 12V battery if you don’t have a charger at home. These are only recommended for emergency use. It’s better to buy a specified 12V charger to charge your battery.

About Daniel

Daniel is a tech enthusiast and repair technician who loves experimenting with various gadgets and home appliances. On this blog, he shares a troubleshooting guide for software and hardware faults.

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