the only possible difference you might overlook is that your friend might have a 9cell battery (the battery is quite big that it raises the back of the laptop) and you have a 6 cell battery (which your laptop is as flat as a table).  9 cell batt = 90w adapter (actually, itz 85Whr adapter),  6 cell batt = 65w adapter.

 

 

try to detach both of your batteries and you willl see the inside face of the battery which type it is. :)

 

hope i clarify things for you.

I think they send what they have with the 65 watt battery. I got the 90 watt charger with the 6-cell battery with my M1530.