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Hey, I'm in a bit of a situation. I currently have a pretty ancient laptop (Don't judge me, toying around with an old OS can prove to be pretty fun), however I no longer have access to a charger for it. I've been looking on the Internet for laptop chargers, however I cannot find a single one that matches amps and wattage (the amps and wattage are higher than the laptop's power rating). However, I can find ones that match the voltage.

Will these chargers work with my laptop? Or does it need to match the power rating exactly?

My laptop's power rating is 16V 2.2A 35W. The laptop charger I'm looking at right now is 16V 4.5A 72W.

Oh, and from what I can see in the pictures the charger's output jack seems to be the right size for my laptop.

asked Jul 24 '11 at 18:30

Frinkeldoodle's gravatar image


edited Jul 24 '11 at 18:33

It'll be okay.

The only thing that matters most of the time when buying a laptop charger is the voltage. Higher amps only mean it'll charge the batteries faster.

answered Jul 24 '11 at 18:46

Billy%20Aoki's gravatar image

Billy Aoki

Thanks for letting me know!

(Jul 24 '11 at 18:47) Frinkeldoodle Frinkeldoodle's gravatar image

Personally I would make sure they are pretty close, you also want to check although it's not to much of an issue anymore unless your charger has a center pin ... is polarity.

For battery life is better to charge with low amps and for a long time. I would prefer ,not to use a charger with more than 1A.

Some battery reading:

Understanding lithium-ion (http://batteryuniversity.com/learn/article/understanding_lithium_ion)

Charging lithium-ion batteries (http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries)

How to prolong lithium-based batteries (http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries)

From the last page linked:

Generally speaking, batteries live longer if treated in a gentle manner. High charge voltages, excessive charge rate and extreme load conditions will have a negative effect and shorten the battery life. This also applies to high current rate lithium-ion batteries.

Not only is it better to charge lithium-ion battery at a slower charge rate, high discharge rates also contribute the extra wear and tear..

answered Jul 24 '11 at 20:04

zerocool898's gravatar image


This is very true. Thank you for reminding me of this, for if this battery stops working, I can't get one to replace it :P I'll try to look as hard as possible for a battery that gets as close as possible to 1A.

(Jul 25 '11 at 03:57) Frinkeldoodle Frinkeldoodle's gravatar image

Actually, most if not all of the newer laptops from 1-2 years ago have built-in functions to stop charging the batteries once they're full.

(Jul 25 '11 at 08:50) Billy Aoki Billy%20Aoki's gravatar image

Yes, but this is an ancient laptop, one back from the days where Windows 95 was the standard and 16 MBs of ram was all you needed to run an operating system. I think, though, it stops charging the battery when the battery is full and it just goes into running from outlet mode.

(Jul 26 '11 at 15:55) Frinkeldoodle Frinkeldoodle's gravatar image

Wouldn't the laptop just draw the required current from the charger? e.g the laptop would only draw 2.2A of the available 4.5A from the newer charger as that is all it needs, also wouldn't using a lower rated charger be dangerous and could possibly overheat/burnout because the laptop is trying to draw more current than the charger is capable of?

(May 26 '12 at 06:34) George George's gravatar image

Correct me if I'm wrong but that I how I thought it worked.

(May 26 '12 at 06:35) George George's gravatar image

the rated current and wattage on the charger must be at least what is rated on the laptop (1.5 times more is best and should pass UL certification, not that you are concerned with it), the rated voltage on the charger must be the same of that on the laptop.

answered May 26 '12 at 13:49

trueb's gravatar image


I saw this old post here and just had to correct the person for the safety of the people who may follow their advice.

The things you have to pay attention to is that the voltages are the same, and the wattage is the same or greater than the power supply you are replacing.

If the voltage is different, it either may not start your system, or will fry the system. With the voltage being higher the laptop will draw a higher amount of current, can send higher voltages to your rechargeable battery pack, and even cause them to possibly explode!

If the wattage is less than the one you are replacing then the charger will not be able to supply the required current to properly operate the laptop. You may be able to do this if you are not using the full power of the laptop but it is not recommended. The battery may not charge, the charger may get extremely hot, burn out, or even catch on fire because you are drawing too much current from it.

Higher wattage does not mean that the battery will necessarily charge faster, all that it means is that if your laptop needs more power it will be available. It doesn't mean that your laptop will use it. It WILL NOT damage your laptop to have the power supply be able to supply more current. The wattage is what is available for the system to use, not what it MUST use. The power supply wattage is a function of voltage * available current * power factor (varies depending on type of load resistive, capacitive, inductive) * efficiency. In NO WAY does the wattage mean that if you have a 1000 watt power supply it is going to shove those 1000 watts through your system.

To put it in a different manner... Batteries are rated in amp hours... if you buy a battery rated for 60 amp hours( such as the following http://www.amazon.com/Shuriken-SK-BT60-60ah-Battery/dp/B0024ODKC0) and draw 1 amp off the battery for an hour straight you would have 59 amp hours left. Just because the battery CAN supply 1500 amps doesn't mean the 1 amp draw you hooked up will get all 1500 amps at once. The load will take only what it needs. It is not going to be forcibly pushed through damaging it in any way.

For the power supply and laptop it will mean your system can draw its 700 watts, and still have room to spare, possible even having the power supply run cooler and more efficiently, thus being better for the environment as well.

answered Sep 06 '12 at 18:58

Billtopia's gravatar image


edited Sep 06 '12 at 21:22

it will work but the higher amps will not only charge the battery faster it will tax the battery more and the internal part of the computer too if its ran while hooked to the charger the AMPS do for sure make a big difference and if they are much more then they should be dont not leave it plug ed in while you are far from it because heat will be big not only could it get hot enough to set things around it on fire or cause spontaneous combustion but it can cause over charging of the battery and battery explosion ..

Just saying it it with caution no matter what any one thinks the wrong amperage is a problem same as using a 40 amp fuse in a 20 amp circuit because you keep blowing fuses now the bad or shorting wires can cook and burn everything out ..

just because something could work dont mean it should be done its not voltage in electrical shock that kills its the amperage put that to work in all you do with this stuff any :)

any amps the batery cant use turns into addition heat basically thinks of the heat doubling or even tripleing if the battery charging normal get 120 to 180 degrees it can get 250 and more if over pushed ..

answered Sep 06 '12 at 20:24

jadtechnic's gravatar image


edited Sep 06 '12 at 20:29

I've had HP chargers with identical connectors that varied slightly in some of their settings but worked in multiple laptops with identical connectors. I don't think it's a huge issue.

answered Sep 06 '12 at 21:20

Duodave's gravatar image


I had a similar situation with my sisters laptop. She needed one for her computer because hers broke. The first one I bought her was a cheep one on eBay. That didn't work, so I had to buy her the real one. $50.00. It worked. So, I'd recommend, not using eBay. Not sure, but try not to go too cheap like I did. You will possible be disappointed. The right one might be on the OEM's Website. If not, it could be on newegg.com. Amazon is hard to look for a specific item.

Also, Best Buy might sell universal chargers. If there are any more best buys around your place.

answered Sep 06 '12 at 22:36

Curtis%20Coburn's gravatar image

Curtis Coburn

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Asked: Jul 24 '11 at 18:30

Seen: 18,317 times

Last updated: Sep 06 '12 at 22:36