# Can I use a power adapter from one laptop on another laptop?
**URL:** https://boards.straightdope.com/t/can-i-use-a-power-adapter-from-one-laptop-on-another-laptop/912148
**Category:** Factual Questions
**Created:** [June 23, 2020, 12:20am UTC](https://boards.straightdope.com/t/can-i-use-a-power-adapter-from-one-laptop-on-another-laptop/912148 "2020-06-23T00:20:37Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@RTFirefly](https://boards.straightdope.com/u/RTFirefly)
#### Post date: [June 23, 2020, 12:20am UTC](https://boards.straightdope.com/t/can-i-use-a-power-adapter-from-one-laptop-on-another-laptop/912148/1 "2020-06-23T00:20:38Z")
And if so, does it have to be an exact match with respect to voltage and amperage?
My laptop’s adapter seems to be having problems. Its output is 20V, 2.25A. Can I use another adapter of similar but not exact voltage and amperage, or would that risk screwing up my laptop?
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### Author:  [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)
#### Post date: [June 23, 2020, 12:23am UTC](https://boards.straightdope.com/t/can-i-use-a-power-adapter-from-one-laptop-on-another-laptop/912148/2 "2020-06-23T00:23:32Z")
IMHO you will be OK if the output voltage is the same, and the amperage is the same or higher. Anything other than that and you would be inviting possible damage, although it may work.
I think your bigger problem is getting the plug to match.
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### Author:  [@RTFirefly](https://boards.straightdope.com/u/RTFirefly)
#### Post date: [June 23, 2020, 12:25am UTC](https://boards.straightdope.com/t/can-i-use-a-power-adapter-from-one-laptop-on-another-laptop/912148/3 "2020-06-23T00:25:59Z")
Guess I order a new adapter then! My others have higher amperage, but are 19V.
Thanks for the info!
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### Author:  [@leahcim](https://boards.straightdope.com/u/leahcim)
#### Post date: [June 23, 2020, 12:31am UTC](https://boards.straightdope.com/t/can-i-use-a-power-adapter-from-one-laptop-on-another-laptop/912148/4 "2020-06-23T00:31:36Z")
My guess would be that if the laptop wants 20V and you connect a 19V adapter, it is probably within design tolerance.
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### Author:  [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)
#### Post date: [June 23, 2020, 12:49am UTC](https://boards.straightdope.com/t/can-i-use-a-power-adapter-from-one-laptop-on-another-laptop/912148/5 "2020-06-23T00:49:01Z")
IANAEE but this is probably true. A 5% voltage variance may be OK. (A higher voltage would probably be more risky than a lower one.)
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### Author:  [@kanicbird](https://boards.straightdope.com/u/kanicbird)
#### Post date: [June 23, 2020, 12:05pm UTC](https://boards.straightdope.com/t/can-i-use-a-power-adapter-from-one-laptop-on-another-laptop/912148/6 "2020-06-23T12:05:55Z")
I’ve done it on several models, it really is a moment of true ‘plug and pray’, always worked fine even with slightly different voltages.
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### Author:  [@Chronos](https://boards.straightdope.com/u/Chronos)
#### Post date: [June 23, 2020, 1:05pm UTC](https://boards.straightdope.com/t/can-i-use-a-power-adapter-from-one-laptop-on-another-laptop/912148/7 "2020-06-23T13:05:26Z")
A lower voltage might not work, but probably won’t damage the device.
A higher voltage might damage the device.
A higher current rating is fine.
A lower current rating probably won’t damage the device directly, but might damage the cord, and could possibly be a fire or shock hazard.
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### Author:  [@Si\_Amigo](https://boards.straightdope.com/u/Si_Amigo)
#### Post date: [June 23, 2020, 1:48pm UTC](https://boards.straightdope.com/t/can-i-use-a-power-adapter-from-one-laptop-on-another-laptop/912148/8 "2020-06-23T13:48:45Z")
I have had situations where different adapter would work when the battery was charged but would not have enough umph to charge up a completely depleted battery. Found this out while I was on the road and had to make an emergency trip to Best Buy before they closed.
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### Author:  [@newme](https://boards.straightdope.com/u/newme)
#### Post date: [June 23, 2020, 4:51pm UTC](https://boards.straightdope.com/t/can-i-use-a-power-adapter-from-one-laptop-on-another-laptop/912148/9 "2020-06-23T16:51:31Z")
I suppose that polarity might also be an issue. My adapter is + in the center, but some might be - in the center of the plug.
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### Author:  [@icbm](https://boards.straightdope.com/u/icbm)
#### Post date: [June 23, 2020, 9:07pm UTC](https://boards.straightdope.com/t/can-i-use-a-power-adapter-from-one-laptop-on-another-laptop/912148/10 "2020-06-23T21:07:35Z")
Dell has been using the same plug on their laptop power things for years. They come in a variety of wattages, (60/90/120) though, and the laptop will alert you if you connect one that is under powered and say it won’t be able to charge the battery or run at full speed. When you have to service Dell laptops for clients it’s nice to not have to make sure they’ve left the power thing behind. It’s also a bad thing because Dell systems communicate with the power thing and will usually refuse to work 100% with universal replacements.
[https://lh3.googleusercontent.com/proxy/1LgwnwC45CW0y5jxoooM7ThXD1085jTXMEfiZ6agDRDUA9yTPTIZk5ccJ2hplKz-RELhRhZqSvND49KfpSLxMRGfYQ](https://lh3.googleusercontent.com/proxy/1LgwnwC45CW0y5jxoooM7ThXD1085jTXMEfiZ6agDRDUA9yTPTIZk5ccJ2hplKz-RELhRhZqSvND49KfpSLxMRGfYQ)
Lenovo has been using their small rectangle for a while too. We’ve been able to use the ones for their Tiny form factor PCs on their laptops.
[ ](https://img.tvc-mall.com/uploads/details/801202722A-7.jpg)
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### Author:  [@iamthewalrus\_3](https://boards.straightdope.com/u/iamthewalrus_3)
#### Post date: [June 23, 2020, 10:18pm UTC](https://boards.straightdope.com/t/can-i-use-a-power-adapter-from-one-laptop-on-another-laptop/912148/11 "2020-06-23T22:18:17Z")
> I suppose that polarity might also be an issue. My adapter is + in the center, but some might be - in the center of the plug.
Center positive is by far the post common for DC plugs like that, but there are indeed center negative ones.
You’ll know you used the wrong one right away from the popping sound and the smoke.
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### Author:  [@jjakucyk](https://boards.straightdope.com/u/jjakucyk)
#### Post date: [June 24, 2020, 2:29am UTC](https://boards.straightdope.com/t/can-i-use-a-power-adapter-from-one-laptop-on-another-laptop/912148/12 "2020-06-24T02:29:14Z")
> [@icbm](#):
>
> Dell has been using the same plug on their laptop power things for years.
They’ve moved to a smaller plug for thinner laptops, so they’re not as universal as they used to be. Still, it was nice to just keep a huge old clunker of a power adapter at my desk to I could plug any laptop into it while doing service (while the plug hasn’t changed in years, the transformers have gotten much smaller and better, though yes the wattage rating might not be up to par for universal use).
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### Author:  [@Didi44](https://boards.straightdope.com/u/Didi44)
#### Post date: [June 24, 2020, 5:07am UTC](https://boards.straightdope.com/t/can-i-use-a-power-adapter-from-one-laptop-on-another-laptop/912148/13 "2020-06-24T05:07:59Z")
As others have said, the biggest issue using a charger not specifically designed for your laptop is the battery may not properly charge your battery at best, kill your battery or even possibly cause it explode and/or catch fire, particularly if they’re lithium ion or lithium polymer. [litium polymer battery explode - Google Search](https://www.google.com/search?ei=Zt3yXrnUGca90PEPxpqa8AE&q=litium+polymer+battery+explode&oq=litium+polymer+battery+explode&gs_lcp=CgZwc3ktYWIQAzIECAAQDToECAAQRzoGCAAQDRAeOggIABANEAUQHjoFCAAQzQJQv40BWL-fAWC9pAFoAHACeACAAZwBiAGLCZIBAzAuOJgBAKABAaoBB2d3cy13aXo&sclient=psy-ab&ved=0ahUKEwi5n7CW1ZnqAhXGHjQIHUaNBh4Q4dUDCAw&uact=5)
Read the back of those third party replacement adapters and they should list exactly which models that work with and state which ones they won’t charge the battery on.
I used to have one of the tiny DVR cameras and to extend the recording time I’d charge some lithium-ion batteries I had left offer from my phones. I’d just tape the bare leads from a usb charger to since I no longer had the phones. That is until one day, one of the batteries bulged to 2x the side and really hot! If I left the charger connected, it would have surely have exploded and caught fire!
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### Author:  [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)
#### Post date: [June 24, 2020, 2:02pm UTC](https://boards.straightdope.com/t/can-i-use-a-power-adapter-from-one-laptop-on-another-laptop/912148/14 "2020-06-24T14:02:32Z")
I have a Dell XPS notebook computer at home on which the charger connects via the USB-C port. I _think_ these chargers are more or less generic, so an Apple USB-C charger can charge a Dell computer and vice versa. Perhaps eventually we’ll standardize on USB-C chargers so generic ones can be used?
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### Author:  [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)
#### Post date: [June 24, 2020, 9:42pm UTC](https://boards.straightdope.com/t/can-i-use-a-power-adapter-from-one-laptop-on-another-laptop/912148/15 "2020-06-24T21:42:15Z")
USB-C is a standard just for the plug and cable; the voltage and current can vary based on the charging device. The chargers are not interchangeable. I have a few chargers with USB-C plugs, but if I don’t use the one that came with my phone, the phone shows a warning that it is charging slowly and recommends to use the OEM charger. It works, but that is not the same as being generic.
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### Author:  [@Chronos](https://boards.straightdope.com/u/Chronos)
#### Post date: [June 24, 2020, 11:11pm UTC](https://boards.straightdope.com/t/can-i-use-a-power-adapter-from-one-laptop-on-another-laptop/912148/16 "2020-06-24T23:11:27Z")
The USB standard also specifies 5 V, and I think it also specifies a limit of 1 A unless the device can negotiate for more. If everyone’s following the standard, then anything that physically fits in a USB socket should be safe to do so.
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### Author:  [@RTFirefly](https://boards.straightdope.com/u/RTFirefly)
#### Post date: [June 25, 2020, 12:39am UTC](https://boards.straightdope.com/t/can-i-use-a-power-adapter-from-one-laptop-on-another-laptop/912148/17 "2020-06-25T00:39:37Z")
Just in case anyone’s still wondering, I wound up buying a replacement charger on Amazon, after Googling the model number on my problematic charger. My wife’s got Prime, so I got her to order it for me; should be here tomorrow.
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### Author:  [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)
#### Post date: [June 25, 2020, 4:23pm UTC](https://boards.straightdope.com/t/can-i-use-a-power-adapter-from-one-laptop-on-another-laptop/912148/18 "2020-06-25T16:23:23Z")
> [@Chronos](#):
>
> The USB standard also specifies 5 V
I overlooked this. But then why does my phone complain about some chargers, and some are fast and some are slow?
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### Author:  [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)
#### Post date: [June 25, 2020, 7:51pm UTC](https://boards.straightdope.com/t/can-i-use-a-power-adapter-from-one-laptop-on-another-laptop/912148/19 "2020-06-25T19:51:45Z")
> [@CookingWithGas](#):
>
> USB-C is a standard just for the plug and cable; the voltage and current can vary based on the charging device. The chargers are not interchangeable.
I checked Amazon and they have USB-C chargers that supposedly can be used with Apple, Dell, or other brands of notebook computers. I actually just ordered one to use with my Dell XPS notebook system to have as spare and because it’s smaller than the one that came with the computer. I think the idea is that they are supposed to be interchangeable.
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### Author:  [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)
#### Post date: [June 25, 2020, 8:52pm UTC](https://boards.straightdope.com/t/can-i-use-a-power-adapter-from-one-laptop-on-another-laptop/912148/20 "2020-06-25T20:52:49Z")
> [@Dewey\_Finn](#):
>
> I think the idea is that they are supposed to be interchangeable.
What’ll happen if you plug a notebook computer into a phone charger?
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