How Long Can Your Car Battery Power Your Laptop?

Laptops are notorious for draining power, and this begs the question of how you can power them using your car battery while on the road.

So, for how long can your car battery power a laptop? A standard battery in your car can charge a 45-watt laptop for 3.7 hours. For a 65-watt laptop, the charge time reduces to about 2.4 hours.

If you happen to use a 90-watt laptop, the battery gives charge for about 1.6 hours, and still has some charge to ignite the engine. When the inverter is excluded, the charging time should be about 4.5 hours, 2.9 hours and 1.9 hours respectively.


Of course, the estimations given are based on the assumption that your battery is filled to the capacity. Besides, it’s assumed that the laptop has a proper charging cord. If any of these factors are affected, it means that the charging time is likely to reduce significantly.

If you run out of laptop power while out there on the road, you shouldn’t worry because the battery in your car can be of much benefit. You only need to know how to connect the laptop to the power supply.

How Can You Charge Your Laptop Using a Car Battery?

Of course, this is one question that most drivers are always asking whenever they find themselves in the dark after their laptops run out of power. Say, for instance, you are out there camping, and then your lecturer requests you to resubmit the assignment. Your computer is out of charge, and unfortunately, the job isn’t saved on your smartphone.

The experience can be traumatizing as you know these assignments and work reports usually come with deadlines. However, it doesn’t have to be as ugly as it sounds. With your car around, you can power up the laptop and deal with the task without any worries.

There are two ways to connect the computer to your car battery. One, you can have it connected directly, without an inverter or use the inverter. Whatever option you pick has an impact on the charging time. Of course, when the inverter is absent, the amount of charging time increases.

Using a Power Inverter to Charge Your Laptop in a Car

When it comes to powering your laptop in a car, it would be best if you applied a power inverter. The inverter eases the connection and is safe to use for both your car battery and laptop. To make this possible, you ought to have the inverter itself. Also, you will require a functioning cigarette lighter.

Therefore, if the one in your car isn’t working, the charging process won’t be effective. One thing that you must remember is that you can’t charge the laptop when the vehicle is idle. By doing so, you will end up draining your battery sooner than you had anticipated. Below is a step-by-step guide on how to connect the laptop to charge like a professional.

1. Prepare

As opposed to charging your laptop using a wall socket, when using your car battery, you need a special adapter to run on DC. Therefore, before you begin the procedure, you have got to ensure that you have the right adapter. For the adapter to work, you will have to remove a portion of your power cord and replace it with a DC cord. The DC cord is designed to fit perfectly into a car cigarette lighter socket.

What if you don’t have an adapter? You can quickly get one at your nearest electronics shop. Also, you can find these adapters cheaply at online stores such as Amazon. When buying an adapter, it would be best if you went for the universal version as opposed to the model-specific versions. By doing this, you will be avoiding the misery that comes when a need arises to top up a different laptop.

2. Plug the Adapter into Your Laptop

Once you are sure that you have got the right DC adapter, and it’s connected to the other end of your laptop charger, it’s time to get the job done. Start by attaching the right end of the charger into your laptop.

3. Place the Battery in a Secure Location

With the charger inserted into the device’s charging port, continue to find a safe spot to place the laptop. Remember, you have to charge the laptop while the car is on the move. Therefore, you ought to ensure that it’s placed on a firm ground to avoid damaging while on the move. An empty seat works perfectly as the place to safeguard the laptop.

4. Plug the DC End into Your Car’s Cigarette Lighter

With the charger in the laptop’s charging port, you can continue and plug the DC end into your car’s cigarette lighter. It’s the same way you would do with a phone charger. Therefore, that shouldn’t be a problem.

5. Start the Car and Drive

With the charger connected on both ends, you should go ahead and start the vehicle. The laptop should start charging immediately, and that’s based on the model you acquired. It would be best if you allowed the battery to continue charging for the estimated timeframe to avoid depleting your battery. By surpassing the expected time, you may end up with a flat battery hence trouble when starting your car the next time.

Can the Inverter Empty Your Car’s Battery?

Currently, you will find power inverters I different ratings. Say, for instance, you will find the 150W, 240W, 240W, 300W, and 500W. When charging your laptop in a car, a laptop charger with a rating of 150W and 300W is more than what is needed.

With the capacity, you can expect your battery to drain faster as opposed to when you are using an adapter with a lower rating. If left connected overnight, the inverter can end up wasting your car’s battery. Therefore, it would be best if you didn’t use the inverter to charge when the vehicle is idle.

Can an Inverter Harm Your Car?

If your laptop inverter is misconnected, you may end up damaging the cigarette socket. That’s why it’s recommended that you understand how to connect the inverter first before you even start shopping for the right power inverter. It would be best if you went for a branded inverter for the sake of convenience. Those cheap inverters you find in the stores can do you more harm than good.