The Dc rating on the laptop really means little, the "black" block that you connect between the wall outlet and the laptop converters the power to an more appropriate energy that the laptop needs ...

The "Black block" between the wall outlet and the laptop converts your 110/230 V AC(Alternating current) to 19v DC(Direct current) and should come with Amps reading as well ...

Clearly the Higher the DC value is the more power the laptop needs ...

Hope this helps ...

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