How To Charge 12V Car Battery With A 19V Laptop Charger

12 Volt Car Battery Charger Schematic Diagram Wiring Diagram
12 Volt Car Battery Charger Schematic Diagram Wiring Diagram from

How to Charge 12V Car Battery with 19V Laptop Charger


Having a dead car battery can be a frustrating experience, especially when you’re on the go. In such situations, you may wonder if you can use your laptop charger to charge the car battery. This article will guide you through the process of charging a 12V car battery using a 19V laptop charger.

Checking Compatibility

Before attempting to charge your car battery with a laptop charger, it’s crucial to check the compatibility of the two devices. Most laptop chargers have a voltage output of 19V, which is higher than the 12V required by a car battery. However, it’s still possible to charge the battery using a step-down converter.

Using a Step-Down Converter

A step-down converter is a device that can convert a higher voltage to a lower voltage. To charge your car battery with a laptop charger, you’ll need to connect the charger to the step-down converter. The step-down converter will then adjust the voltage to the appropriate level for the battery.

Connecting the Charger and Converter

Start by connecting the laptop charger to the step-down converter. Ensure that the charger is unplugged from any power source before making any connections. Follow the instructions provided with the converter to properly connect the charger.

Connecting the Converter to the Battery

Once the charger and converter are connected, you’ll need to connect the converter to the car battery. Use the appropriate cables and connectors to establish a secure connection. Make sure to connect the positive terminal of the battery to the positive terminal of the converter and the negative terminal to the negative terminal.

Charging the Battery

After all the connections are made, plug the laptop charger into a power source. The step-down converter will regulate the voltage, ensuring that the battery receives the correct charging current. Keep an eye on the battery while charging and monitor its voltage regularly.

Safety Precautions

When working with car batteries, it’s essential to take proper safety precautions. Ensure that the area is well-ventilated to prevent the buildup of flammable gases. Avoid smoking or using open flames nearby. Additionally, wear protective gloves and goggles to protect yourself from any potential accidents.


Charging a 12V car battery with a 19V laptop charger is possible with the use of a step-down converter. However, it’s important to ensure compatibility and follow safety precautions to avoid any damage or accidents. If you’re unsure about the process, it’s always recommended to consult a professional or use a dedicated car battery charger for optimal results.