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I ordered online for a Lenovo 65W AC adapter for Lenovo G550 laptop.

My original adapter had specifications: 19V 3.42A (64.98W)

While the one I got has specifications: 20V 3.25A (65W)

I want to know if it is safe to use the second adapter with my laptop.

Edit 1: The new adapter is also from Lenovo.

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marked as duplicate by Ƭᴇcʜιᴇ007, Karan, Breakthrough, Tog, gronostaj Jul 11 '13 at 7:09

This question was marked as an exact duplicate of an existing question.

Did you buy it from Lenovo or from a 3rd party? If from a 3rd party, I would not trust it. It does not provide enough current (3.25A < 3.42A) and will force more than the expected voltage through the laptop (20V > 19V). These differences might be within tolerances, but there's no guarantee of that, and if they aren't, then you can fry your laptop at worst or at best it simply won't provide enough power to charge the battery.

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It is from Lenovo. – Xolve Jul 8 '13 at 20:10
It'll provide enough power, but the voltage difference concerns me; if unable to make absolutely certain from the laptop's documentation that it can accept 20V input, I would not use the adapter -- even if the DC-DC converter can be overvolted and still remain functional, doing so will almost certainly shorten its lifetime. (As far as I know -- it'd be nice to have an EE confirm that, my knowledge of the field being only that of an interested and somewhat capable hobbyist.) – Aaron Miller Jul 8 '13 at 20:13

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