what happens if power supply is 90 w instead of 120 w

[Adi Cretu]

asus k53 sv has a 120 w power adapter ,what happens if i use 90 w adapter

 

[CraigN]

The battery won't charge as fast, and it could have negative effects on the battery's long term ability to hold the same charge if you use a lower-power charger.

There's also a possibility that it just flat out won't charge because the laptop will see it as incompatible (much like your cell phone does if you plug it into too weak a charger), or is consuming more energy than your charger is providing. I would recommend you stick with the power adapter it comes with, unless there is something wrong with it, then I would replace it with one of equal power.