What is a Laptop car charger?

A Laptop car charger is a type of power supply typically one that is used in the car to power the laptop. Other names include Laptop Car Charger, Auto Power Adapter, Auto Air Power Adapter, Auto Notebook Power Adapter, or Auto DC Adapter.

The Laptop car charger operates by plugging into the cigarette lighter socket in the car. It is able to convert the 12V voltage (sometimes 24V in some heavy-duty trucks or military vehicles) of the automobile electrical system, into the required input voltage of the laptop. By connecting the output plug of the adapter to the laptop, users can then power the machine in the car. Most Laptop car chargers are capable to run the laptop and charge the laptop battery simultaneously.

A Laptop car charger looks very similar to an AC power adapter. They are usually rectangular in shape and black in color and consist of an input and an output cable. The major difference between the two is the AC power adapter is usually equipped with a power cord as the input cable, whereas the Laptop car charger utilizes the cigarette lighter plug to draw current from the battery of the vehicle.

Below is a typical setup of a Laptop car charger at work:


Who needs a Laptop car charger?

Anybody who tends to operate a laptop in the car for a long period of time needs a Laptop car charger. The following are some examples of the people/organizations that can use the Laptop car charger to enhance their mobile computing experience:

  • Law Enforcement
  • Fire Services
  • Emergency Medical Services
  • Public Transportation System
  • Public Utility Services
  • Waste Management
  • Commercial Service and Delivery
  • Warehouse Management
  • Military and Intelligence
  • Traveling Professionals

The Laptop car charger Buying Guide

Unlike the AC Power Adapter, the Laptop car charger usually doesn't come in the original laptop package. People who want to use the Laptop car charger need to purchase the adapter separately. Most Laptop manufacturers offer the Laptop car charger option. Buying from them guarantees the full compatibility between the laptop and the adapter. However, it is also often the more expensive way to obtain the adapter. We sometimes see the price of the Laptop car charger option from the laptop manufacturer being 2X compared to the alternative solutions.

If you know what to look for, finding a cheap alternative Laptop car charger solution with similar performance is easy this is the reason why we constructed this Laptop car charger Buying Guide. In this document, you are going to learn the important parameters to consider when searching for your alternative laptop car charger.

Input Voltage Range

Most passenger vehicles and trucks are designed to output a 12V voltage at the cigarette lighter socket/utility power outlet. However, the voltage on the outlet is not always regulated perfectly at 12V. In some situations, such as during the car's engine cold-start process, the output voltage may vary. It can sometimes go as low as 10V or as high as 18V. Having a Laptop car charger fail to work in the full range voltage swing of your vehicle utility outlet can post issues.

The minimum accepted input voltage range for a Laptop car charger is from 11V to 16V. An adapter with this specification is usually cheap in price. But, the owner might run into the potential issue that the adapter sometimes stops functioning. The better input voltage range specification is from 10V to 24V. With the wider range design, the auto adapter can always guarantee continuous operation.

There are situations when users need to have a Laptop car charger working in an even wider range. For example, military vehicles or some foreign-made heavy-duty trucks are equipped with the 24V battery system and have the chance to output a voltage as high as 32V at the cigarette lighter socket. In this case, an adapter capable of working in the 10V to 32V input voltage range is required. Additionally, some warehouse management services are performed by using the mobile data terminal installed on a forklift of which the utility outlet can generate a voltage as high as 60V. A voltage step-down device is needed to be installed between the forklift battery and the auto adapter.

Fuse Design

The Laptop car charger needs to have a fuse built-in on the input to protect itself because of the unstable utility outlet output. In the automobile engine ramp-up or slow-down process, there might be an extra current surge flow into the auto adapter. Without the proper fuse installed, the surge current might damage the auto adapter, and sometimes the laptop.

Some vendors put the fuse on the adapter main body. It is usually the more expensive way to implement the fuse but offers an easier way to have the fuse replaced. Others put the fuse inside the cigarette lighter plug for a cheaper cost but harder for the fuse replacement. When you buy the auto adapter, you should check if the package comes equipped with some spare fuses for future use. Believe us, there is a high possibility that you will need to replace the fuse sometime in the future.

Output Power Level

Nowadays, mainstream laptops usually ask for no more than 70W input power. The manufacturers have a tendency to carefully select the components they put onto the laptop motherboard, to control both the heat generation inside the laptop chassis and the cost to build the laptop. However, there are machines that demand more than 70W out there. Some gaming notebooks and mobile workstation solutions are more power-hungry to support the installed, high-end graphic display card, or the fast multi-tasking CPU. The best way to determine what power level you need is by looking at the label on your laptop AC power adapter. If you have a 90W AC power adapter for your notebook, try to get a 90W auto adapter. As long as you can match the power level, the auto adapter should be able to support the energy needed to run your laptop on the road.

Output Voltage

The output voltage specification you need to look for on a Laptop car charger depends on the input voltage requirement of your laptop. Most laptop manufacturers have now settled on two voltage systems: 12V and 19V. Some still use odd voltages, such as 15V. The best place to look for the right needed output voltage is on your AC power adapter.

It is also recommended that the output voltage of the Laptop car charger be as clean as possible. However, adapter vendors usually won't make the voltage regulation and noise specification available to the public. (Read this link for the definition and measurement of the voltage regulation and noise on the adapter output.)

Output Plug Dimension

One of the complaints regarding the laptop design is that different vendors tend to implement different input DC Jacks on the laptop. In addition, the information on the DC jack dimension is usually not widely available to the public. By doing so, laptop vendors force the laptop owners to buy power accessories directly from them to ensure the power adapters have the correct output plug which can match the DC jack on the laptop. The notebook vendors can thus earn high profits due to the high listed price of the power accessories.

Below you will find the commonly used power adapter output plug:

plug_polarity Cylindrical shape 2-pin plug: this is the most common type of output plug used on Laptop power adapters. They have several different variations, such as:

(image--3)

o Outer plug dimension (OD): 5.5mm, Inner plug dimension (ID): 1.7mm
o OD: 5.5mm, ID: 2.1mm
o OD: 5.5mm, ID: 2.5mm

One thing to note is the center pin is sometimes designed with reversed polarity: sometimes the center pin represents the power rail, and sometimes it is the ground rail. The best place to check the desired center pin polarity is on the AC power adapter label. The first picture below shows the output plug is a center pin negative design. The second one is the center pin positive design.

4-pin snap and lock plug: Sometimes it is called a power Mini-DIN connector. They can usually be identified by an engraved symbol on the back of the plug, consisting of two wide arrows pointing in opposite directions, but parallel to each other, or sometimes one wide arrow inside a box, pointing towards the end of the male connector.

3-pin plug to enable the data communication between the laptop and the adapter: the latest technology in laptop power accessories is to implement a data pin inside the adapter output plug. When the laptop registers that it has already used the full allowable power from the power adapter, it will try to limit the power usage in the system by shutting down or slowing down a system function. The 3-pin plug is easily identified by its larger cylindrical shape. There are also plug adapters to make the old 2-pin plug work on the new 3-pin plug system (and vice versa).

Again, the best place to find the output plug information is on your AC power adapter. We are in the process of establishing a database with accurate plug information for each laptop existing on the market. Please check back for more information later.

Auto / Air Adapter

empower_plugSometimes the vendors promote their products as auto/air adapters. The add-in phrase, air, simply indicates that the adapter can be used to power the laptop on the airplane if the user can locate an empower connector to plug in the auto/air adapter. It is a common practice to embed an empower plug inside the cigarette lighter plug of the Laptop car charger. The front tip of the cigarette lighter plug is designed to be detachable so the empower plug can be shown. Please see the below picture for reference.

Do you need the air adapter feature? It depends. Not all airline companies deploy empower connectors on the seats on the airplane. You should first check the information on seatguru.com, determine if the airline you usually take offers this feature, and then make your decision.

Misc. Features and Functions

There are other less important, but still viable features and functions to consider when purchasing the Laptop car charger. For example: