Charging a 45w laptop with a 65w charger. bad? (Explained)

You may have heard that you can’t use a laptop charger that provides a higher wattage than the laptop itself requires. or can you use a 65w charger on a laptop that requires 45w?

A lot of people are wondering if this is true or not. So, can you use a 65W charger on a 45W laptop?

The answer is yes. You can use a 65w charger instead of a 45w charger. If the voltage is the same, the laptop will only utilize the power it requires from the charger. You will be fine.

However, it is beneficial to use a higher watt charger than a lower one because using a lower watt can put a load on the charger and can cause heating.

In this blog post, we will further explain what wattage is and when you should use a higher wattage charger on a laptop.

What is wattage?

A wattage is a unit of measurement that defines the amount of power that a device uses per second.

Or A watt (W) is the amount of work accomplished when one ampere (A) of current passes through an electrical potential difference of one volt (V). It can be expressed as

W = V . A

So basically, you have to take the product of the output voltage supplied by the charger with the output amp.

Laptop chargers are usually rated in watts. In most cases, the laptop comes with a charger that provides the specific wattage that it needs.

Using a charger with a higher wattage than needed.

As we mentioned earlier, you can use a charger with a higher wattage on your laptop.

Because the laptop will only use as much power as it needs from the charger. So, if you are using a 65w charger on a laptop that only requires 45w, the laptop will only use 45w, not 65w.

But before using a higher watt charger, you need to check the voltage. Because if the voltage is higher than what the laptop requires, it can burn circuits, etc.

It is important that the new supply has the same voltage as the original supply. Not higher or lower. For example, you don’t want to power a laptop that takes 14V with a power supply that supplies 19V.

The amperage will fluctuate proportionally with the wattage. The amount of amperage entering the battery will be handled by the laptop if the voltage is within the limit of what the laptop requires.

Voltage is pushed amperage is pulled.

This is why you should always check the voltage before using a different charger on your laptop.

This is also the reason that you should avoid using a charger that supplies less amperage because the laptop will try to pull more amps than what the power supply can supply. This can result in heating both the charger and the laptop.

What is the difference between a 45W and a 65W laptop charger?

The simple answer could be that the difference between the two is 20w. You can use the 65W charger.

The brick will be a little larger and heavier, and it might charge your battery a bit faster. If they are from the same company, the plug and the voltage will be the same, so it will work with your laptop fine.

45w vs 65w charger Dell

Since both of these chargers are from the same company, they have the same output voltage, which is 19V. You can use a 65w charger on a 45w laptop. But if you have to choose between the two, then it is better to go for the 65w one.

Can I use a 65w charger instead of 30w?

In short, yes you can. If your laptop requires 30 watts and the charger is 65-watt then it’s completely safe to use that charger. It will charge at a regular speed because only 30w will be used out of the total 65w.

Take an example of a light bulb, if you put a 100-watt bulb in a 60-watt socket it will still only draw 60 watts of power it is not designed to draw 100 watts.

The same goes for your laptop and a lot of other devices it will only draw as much power as it needs from the charger.

Is a 65W charger safe?

The safe wattage range for a wall adapter is 45 watts to 96 watts, which will most certainly be able to charge your laptop.

So,65W laptop chargers are completely safe to use if the voltage is within the limit for both the phone as well as the laptop.

They’re designed to be used with laptops that require higher wattage. So, if your laptop only requires 45W of power, using a 65W charger will be perfectly fine.

Is 45w enough to charge the laptop?

As said earlier 45w lies in the safe range for an adapter so it is enough to charge the laptop.

But if the laptop is capable of handling higher watts than that then it won’t be enough. The laptop will charge, but not as quickly as it could with a higher wattage charger.

So it is better to use a higher watt charger if the laptop is capable of handling it.


I hope you found this article helpful. Laptop chargers come in a variety of wattages, and you can usually use a charger with higher wattage on your laptop without any problems.

However, it’s important to make sure that the voltage is compatible with your laptop, as using a charger with incompatible voltage can damage your laptop.