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I have a Lenovo laptop and my adaptor has gone bust. The DC rating on the original adapter is 20V 3.25A 65W. I can't find the exact same part anymore and I am being advised another Lenovo adapter with the specs: 19V, 3.42A 65W. Will using this cause damage to my laptop? What are the implications?

My apologies: I posted the same specs for both adapters. I've corrected them now.

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As long as the input range is fine for your location and the output is the same or even quite similar, shouldn't be a problem at all. – Karan Dec 24 '12 at 15:26
Did you mean both of those specs to be the same? – Kazark Dec 24 '12 at 16:26
Kazark - I did not. I posted the wrong specs, my apologies. I've corrected them now. – Bharath Dec 26 '12 at 3:56
I think a 5% difference in voltage is probably OK in most cases. The current ratings need to be in the same ballpark, but 20% less or 50% more is generally going to be fine. In general, if the adapter is too far undervoltage I would expect that the laptop would simply not charge -- it would not damage anything. And probably if the adapter is too far overvoltage the laptop will shut down to protect itself. – Daniel R Hicks Dec 26 '12 at 4:03

You will not damage your laptop with that other adapter. The lower amperage output will simply mean that your laptop will not charge as fast.

You may be able to find a universal adapter that will match your current adapter. But again, you won't have to worry about any damage as it is providing a minuscule amount under.

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For the sake of completeness: The chargers' polarities also have to match. But since they're from the same brand, that shouldn't be an issue. – Dennis Dec 24 '12 at 15:57
Umm.. the difference is that one is 20v and the other is only 19. This may be close enough to work, or may not. – psusi Dec 26 '12 at 4:05
@psusi The difference was fixed after I had answered the question. I have edited the answer to reflect the changes to the question. – JKM Dec 26 '12 at 6:32

19v may be close enough to work, but you should try to find one that is 20v with at least the same amperage rating.

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Personal pet peeve: "current", not "amperage". – Ignacio Vazquez-Abrams Dec 26 '12 at 4:08

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