Can i use a higher watt charger for my laptop

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Laptop power supplies, does current matter?
Can I use a power adapter with more current but lower voltage on another laptop?

I have an ASUS K50IN laptop which requires an input of 19 V at 3.42 A. Its charger has stopped working (wires cut by rats!). My brother have a charger that is 19 V, 7.1 A. Their polarity is the same and the tip fits correctly.. Can I use this charger on my laptop?

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Oftentimes, we find ourselves looking for substitutes for our technical devices in certain situations. Which is why most laptop users tend to use laptop chargers of a lower wattage power adapter. Although this seems like a nice hack for a while, there might be a few consequences of using a lower wattage charger for your laptop.

Can i use a higher watt charger for my laptop

Also Read: How Many Watts Does It Take to Charge a Laptop?

What Does Charger Wattage Mean?

To put it simply, the wattage indicates the amount of power that can be drawn in once your laptop is connected to the power outlet. Each and every single charger has its own level of wattage, which is why they are categorized as either “high wattage chargers” or “low wattage chargers”.

How Exactly Does a Laptop Power Supply Work?

We can compare the power demanded by your laptop with the need for lighting in your room. Although you might be alright with dimmer lights or lights with lower brightness levels and power such as 45W or 60W bulbs, they won’t be as effective for when you need extremely bright light for work.

Also Read: Can I Leave My Laptop Plugged in Overnight?

Similarly, the supplied power supply of your laptop is built to handle and endure the worst possible charging conditions. And although it may seem to function normally in most cases, it won’t be getting enough power to run high capacity programs.

Once your charger has been plugged into the wall socket, the AC power is automatically converted into DC power and transmitted to the motherboard. The motherboard will then distribute it to various other parts of your laptop, especially the battery as it will be storing DC power that can be used later.

Can I use a Lower Wattage Charger for my Laptop?

The answer is yes. You definitely can use a lower wattage charger for your laptop (you can even charge your laptop without a charger!), but this will directly impact the performance of your laptop itself. For instance, using a 45 watt charger for a laptop that requires 90 watts might not enable it to function at its maximum potential. Again, this greatly depends on the type of activity being carried out on your laptop itself.

Also Read: Laptop Won’t Turn on OR Charge [FIXED]

For instance, if you’re using your laptop to read some article, or if your laptop stays idle with minimal brightness level, the low wattage charger will work perfectly fine. But if you plan on watching a video or a movie at high volume, it is highly likely that your laptop rejects the power coming in through the charger, and switches over to the DC power stored in its battery. Since the laptop will not be gaining any power through the low wattage charger, it will ultimately shut down once the battery runs out.

Also Read: Can You Use a Laptop Without a Battery?

Using a low wattage charger for your laptop will be more of a frustration, rather than a convenience to you. Based on multiple reviews and experiences by users, as well as professionals, it can become quite difficult to properly charge your laptop through a low wattage charger. Since the power trickles in slowly, it might take hours to fully charge your laptop, which is definitely not an ideal situation if you’re in a hurry.

It is possible to charge your laptop battery externally (without a charger) using the USB-C port.

What are the Risks Associated with Using a Low Wattage Charger for your Laptop?

With a low powerage, you can potentially cause a fuse in the power supply, damaging it and various other components of your laptop. Since your laptop will be charging at a slower rate than usual, despite having a high current, the battery of your laptop will get ruined as well. The life of your battery will be substantially reduced, and it will get drained at a much faster rate as well.

Also Read: How to Replace Laptop Battery Cells

Most users also complain about their device and the adapter overheating, since it takes a longer time for the battery to fill up. These cooling problems could also have some other negative impacts on your device, further reducing the performance and capability of your laptop.

There will also be the risk of breaking some components of your laptop as they will be demanding power, but will be unable to get it due to a power shortage resulting from using a lower wattage charger.

Also Read: Laptop Lags Slows Down When Plugged In Charging? [FIXED]

When you use a lower wattage charger, the voltage regulator inside of the motherboard adjusts the voltage in the current to match with the requirements of the internal components of your laptop. This way, you can easily power up your device with a lower wattage charger that has a minimal difference than the one actually required to power up your device. For instance, you can easily charge your 20V PC with a 19V charger without any complications.

But if the difference ends up being significantly higher, you might end up facing complications with the voltage regulator, so much so that it ends up failing or breaking down.

Is it Possible to use a Lower Wattage Charger Without Harming your Laptop?

Realistically, there is one situation where you could use a lower wattage charger without negatively impacting your device and its performance. If you plug in your laptop when the battery is fully charged for external power support, you can avoid both overheating your device as well as ruining the life of your battery.

In case the battery of your device is not charged, make sure that you’re not currently using the laptop while it charges. Doing so will further protect the life of both your laptop, as well as its battery.

Although it isn’t recommended to use a lower wattage charger for a substantially high powered device due to the complications that can occur from it, professionals have deemed it to be safe to use when in a sticky situation. Continuous usage of a lower wattage charger will, however, will be risking serious damage to your precious device.

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How Many Watts Does It Take to Charge a Laptop?

Can I Leave My Laptop Plugged in Overnight?

Laptop Won’t Turn on OR Charge [FIXED]

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Can i use a higher watt charger for my laptop

So I did this search on your answers to power supplies but I’m still not clear about the difference between amps, volts and watts. I’ve got a 130 watt power supply leftover from my last Dell laptop that I would like to use on my new Ultra book, which came with a 65 watt power supply. Both units are 19.5 volts, but the 130-watt is 6.7 amps and the 65-watt has a rating of 4.6 amps. What I’m trying to accomplish is keeping the 65-watt unit wrapped up in my laptop bag and the 130-watt wired into my desk for convenience.

You should be able to use your 130-watt power supply with your new machine if a couple of conditions are met.

Let’s review those conditions.

Swapping power supplies

It can be confusing if you’re not familiar with how a power supply (and to some degree, electricity itself) works.

The rules boil down to this:

  • The output connector must match.
  • The +/- polarity of the output connector must match.
  • The output voltage must be the same.

In addition,

  • The output amperage must be greater than or equal to that required by the laptop.

or:

  • The output wattage must be greater than or equal to that required by the laptop.
Can i use a higher watt charger for my laptop
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Input versus output

You may get confused about which set of numbers to pay attention to.

Somewhere on the power supply itself, there will be a confusing jumble of information and logos, all often in very small print.

There are two sets of numbers we care about are input and output.

Can i use a higher watt charger for my laptop
Power supply input and output specifications. Click for larger image. (Photo: askleo.com)

Input specifies what the power supply itself requires. Normally, it will say something like “AC 100V-240V”, and may or may not include watts or amps. This is what the power supply takes as its input from your wall socket.

Electrical systems around the world use different standards. 120 volts or 240 volts are most common. A label on your power supply that includes something similar to “100-240V” as part of the input specification means the power supply will work with whatever it’s given in that range, be it 100 volts, 240 volts, or anything in between. In other words, it’ll work just about anywhere.

Naturally, you should check to make sure your power supply includes something like “100-240V” if you’re traveling to a location with a power standard different than your own.

Output specifies the characteristics of the power provided by the power supply to your computer. This is often something like “DC 19.5V 4.62A”, meaning that this power supply provides electricity at 19.5 volts and is capable of providing a little over 4.5 amps of electricity.

The input numbers are all about connecting to the wall socket. It’s the output numbers that need to meet your computer’s expectations.

On plugs, sockets, and polarity

Particularly when using a power supply from a vendor different than the one that produced your device, it’s critical that the polarity be correct. The connections have positive (+) and negative (-) wires, and those must match what your laptop expects, or you can damage it.

Among that jumble of logos and small print on the power supply label, there is typically a diagram that indicates polarity.

Can i use a higher watt charger for my laptop
DC adapter polarity. Click for larger image. (Image: Wikimedia commons)

This must match what your computer expects. Unfortunately, while there are generally accepted standards for labeling power supplies, there’s no equivalent for the laptop or computer itself. Look for similar information either on the computer case or in the computer’s documentation.

If you’re not sure, don’t try until you have someone knowledgeable look at it.

The other way to determine what your computer requires is to look at any power supply you already have that works, like the one it came with. For example, if both of your machines are Dell laptops, as long as they use the same kind of power connector (you wouldn’t be able to plug it in, if not), they will be polarized the same way. In Dell’s case, that means the positive lead is in the center and the negative lead is the outside of the connector.

Output voltage must match

The output voltage provided by your power supply needs to match. There is no substitute for that.

If your computer needs 19.5 volts, or the prior power supply provided 19.5 volts, then your power supply must be 19.5 volts. Period.

Normally, if you’ve got the same kind of power supply from the same manufacturer and it can plug in at all (meaning the plugs match), voltage isn’t something you have to worry about. I’ve used different versions of Dell power supplies across a number of different Dell machines.

But regardless of the source or the computers involved, the voltage output by the power supply — the number associated with “V” — must match the voltage expected by the computer you’re plugging it into. If you’ve got an existing power supply you’re replacing, you can read the output voltage from its label.

Amps or watts must be the same or more

I’ll just refer to watts since it’s perhaps more common, but the same comments apply to amps. (Often the power supply label will include only one or the other.)

Unlike voltage, which is a constant, the watts rating of a power supply indicates what it’s capable of. A power supply rated for 130 watts can provide up to 130 watts. It can easily provide anything between zero and 130 watts of power; it just can’t provide more than that.

Your laptop will require a certain number of watts. The power supply you use must provide at least that many, and it’s OK if it provides more.

Since your laptop came with a 65-watt power supply, it’s safe to assume your laptop needs no more than 65 watts of power. That means:

  • The 130-watt power supply will work just fine and will have plenty to spare.
  • The 65-watt power supply will work because that’s what came with the laptop.

So the scenario you’re running should be just fine.

What if watts or amps are less?

If you use an underpowered power supply — one that cannot provide the number of watts or amps that your laptop might require — results are unpredictable.

While rare, it is possible you could damage the laptop or the power supply.

More commonly, your laptop simply won’t charge, or won’t charge as quickly.

Some years ago, I had a higher-end, powerful Dell laptop. I had the opposite scenario of yours. It came with a 130-watt power supply, but I also had a 65-watt power supply.

This machine would, of course, work properly with a 130-watt power supply. But if I connected a 65-watt power supply instead, the laptop would tell me at boot-up, “The power supply that’s connected isn’t powerful enough. I may not be able to recharge; I may only be able to recharge at a very slow rate.”

So in my case, the laptop was able to detect that I had put in a power supply that wasn’t really strong enough. In my experience, most laptops aren’t as informative.

  • Match the connectors
  • Match the polarity
  • Match the voltage
  • Make sure amps or watts are greater than or equal to what is needed

Meet those requirements, and you’re good to go.

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