Why does wattage matter in an ac adapter

I'm still confused. Can I use a laptop charger with a higher wattage? The Caveats. I said in the beginning that there were a few caveats. The Voltage needs to be the same or at least very close to that required by the laptop.

We would generally not recommend using a charger or more or less than 1V of what is required by the laptop. HP have Fujitsu laptops generally require 20V, but we've never had a problem with 19V chargers.

You can not however use a 15V charger on a laptop that requires 19V or vice versa. The output tip needs to match. There are many types of tips. There is the traditional barrel tip which is a simple barrel shape connector with a hole in the middle.

These are measured in the form of 5. These need to match or else the connector will not fit or will be too loose. 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.

The answer is yes. You definitely can use a lower wattage charger for your laptop you can even charge your laptop without a charger! 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. 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. 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. With a low powerage, you can potentially cause a fuse in the power supply, damaging it and various other components of your laptop. Improve this question. Community Bot 1. Gelo Gelo 1 1 gold badge 1 1 silver badge 3 3 bronze badges. Good question, and yosh m's answer is perfect. Just for your own information, an electrical system will draw X amount of current if it is supplied at Y voltage.

If you increase the voltage, the current it draws goes up as well as the power consumption. The device will only "draw" as much current as is able to pass through it limited by its resistance. As mentioned, however, trying to draw more current then the charger is capable of may cause heating problems. Add a comment. Active Oldest Votes. Improve this answer.

Peter Mortensen KeithB KeithB 9, 2 2 gold badges 21 21 silver badges 15 15 bronze badges. If only I could minus 1 your comment for adding nothing useful to the discussion. Mine was an educated guess based on years of experience dealing with this sort of thing. It's been too many years since I last studied for my Ham radio license and so I no longer recall the specifics of electronic theory regarding this. But, as evidenced by the other answer you added nothing to, my guess was as good as his facts.

Read yosh m 's answer if you're interested in the difference. I just explained the downvote, I could have done it without writing a word like the other downvoters The Overflow Blog.