How Long Can a Car Battery Power a Laptop? Simple Guide

When you are engaged in activities that require no access to electricity and are travelling to an area that lacks access to electricity, what can your car’s battery do for your laptop? 

I undertook some research to ascertain the answer as with my previous query. An automobile battery is capable of charging a laptop. I’ll tell you about it in this segment: How Long Can a Car Battery Power a Laptop?

When fitted with an inverter, a car battery can power a laptop for 6.5 hours, a laptop powered by 45 watts can operate for 5.1 hours, and a laptop powered by 60 watts can run for 3.8 hours.

Can You Charge a Laptop in a Car?

Yes, charging a laptop in a car can quickly deplete the battery. When you park your automobile at a location and charge the laptop, your car’s battery can deplete charging your laptop in the car while running will not affect the vehicle’s battery. 

However, to charge your laptop successfully using a car battery, you require a car inverter and the appropriate laptop adaptor. Utilising the inverter with the engine switched off will undoubtedly drain the battery, mainly if done overnight. 

Each car comes equipped with a cigarette socket/lighter next to the car stereo. The inverter should be connected, followed by the laptop adapter.

The inverter converts DC electricity to alternating current so that you can charge the laptop. If you must charge your laptop using your car’s battery, you must use a deep-cycle battery that quickly drains and recharges.

When the vehicle’s motor is turned off, the deep cycle battery should be utilised in conjunction with an inverter. Avoid charging the laptop for more than two hours if you’re using a regular automotive battery with the engine turned off.

Draining the Battery of an Automobile When the Engine Turned Off

When the engine is not running, the battery is responsible for powering the electrical system. It is why, if you keep your headlights on overnight, it will drain your car battery.

The same thing occurs when an inverter uses while the vehicle is parked. While some inverters include a shutdown feature, this does not guarantee that your kick starting will continue to operate once the car battery drains to a specific level.

To crank a kick starter, an immense amount of amperage is required. You risk becoming trapped if you use an inverter to charge a laptop while camping. In this instance, the best answer is to use a deep cycle battery to power the inverter and any electrical appliances as desired.

How Long Can a Car Battery Power a Laptop?

How Long Can a Car Battery Power a Laptop

It’s a little tricky to explain, as a car battery can classify as both a “starter battery” and a “deep cycle” battery. A car battery’s internal structure comprises thin lead plates that provide a greater surface area for conducting current. Now i will talk about How Long Can a Car Battery Power a Laptop?

The alternator recharges it once you begin driving. It can exert a tiny amount of stress on itself (2-3%) for approximately two to three seconds before supplying electricity to your vehicle. You will not get more than ten or so total discharges from a discharged battery by powering various gadgets or appliances with it, as this would damage the battery.

Additionally, deep-cycle batteries include thicker plates, protective alloys on the plates, and a lower surface area, enabling them to withstand hundreds of full or partial discharges.

#1) An Inverter’s Ineffectiveness When Charging My Laptop

When customers purchase new laptops, this is the most frequently used method of powering them. If you wish to continue, you require an inverter to recharge your battery. An inverter converts DC battery power to alternating current, allowing you to use it to power your devices.

Inverting this energy dissipates inefficiencies and heat. On average, an inverter is approximately 15% inefficient. Specific individuals possess more characteristics, whereas others possess less. We will assume a 15% efficiency for our calculations (or an 85% efficiency for those who see the glass as half full).

#2) Inefficacy of the Laptop Port

Laptop power sources are never 100% efficient even when running them off wall power. The cord you are following connects to a rectangular box in the middle. It is the PS, and it converts the 110-volt AC electricity coming from the wall into 19-volt DC.

Despite your laptop plugging into your house’s alternating electricity, it runs on direct current (DO). Inefficiencies in the PSU include the inverter, and 10% is a reasonably common percentage.

How Much Time Can You Run an Inverter Before the Battery Drains?

The amount of electricity utilised is determined by the period of time the inverter can charge a laptop or other electronic equipment. To begin, you should identify the wattage of the gadget and the reserve capacity of the battery.

For instance, if the battery has a capacity of 100 amp hours and the laptop consumes 45 watts of power, it is capable of charging the laptop.

However, if you completely charge your laptop after three hours, you are safe. Larger loads, such as a television, a desktop computer, or other energy-intensive equipment, will rapidly deplete the automotive battery.

FAQs -How Long Can a Car Battery Power a Laptop?

Is It Bad To Use a Laptop in a Car?

As long as you are parked, there is no reason why it should not be. Consider a few factors such as the temperature, especially if you’re working in full sunshine, and keep your door closed if someone fancies a grab and run theft.

How long can I run my laptop on car battery?

Laptops can be charged using a car battery, But the Question Is a Car Battery Powerful Enough to Run a Laptop for a Long Time? With an inverter, an inverter-enabled 60-watt laptop can run for 3.8 hours when powered by a car battery for 6.5 hours, whereas a 45-watt laptop can run for 5.1 hours.

How Long Will a 12v Battery Last?

When not in use, a 12-volt Gel or AGM battery has a typical lifespan of up to six years when maintained. The battery retains around 80% of its initial capacity after five or six years of float voltage operation at an average ambient temperature of 25 degrees Celsius. 

Can a Laptop Stay in a Hot Car?

If your laptop is powered off and kept in the trunk, you can keep it in a hot car for up to 8 hours. Please remove the battery from your computer and keep it in an empty cooler bag with insulating characteristics.

Can a Laptop Overheat in a Car?

Summer heat in a car can reach temperatures high enough to melt plastic, which means that delicate components in your laptop may melt. You risk damaging your hard drive, display, connector cables, and other components just by leaving it in a hot car.


Numerous person inquire How Long Can a Car Battery Power a Laptop? is a critical question. Charging the laptop while the automobile is in motion is an excellent technique. A car inverter is required. 

To choose an inverter, you must access a 12V power source. Unless you’ve installed a long-lasting battery, avoid charging your laptop while the vehicle is not running.

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