Hi I have bought MacBook Pro (15-inch, Early 2011) recently and there was a problem with it. It was charging really slow. 8 hours of charging for full capacity charge. And then I found out the guy I bought the laptop from gave me the 45W Magsafe charger. And I need an 85W Magsafe charger (I guess that is the original one) and on Ebay I find out that there are versions of it. Like A1290, A1343, A1175 and so on. Can I buy any of them without having any compatibility issue? Is it okay to buy any 85W Magsafe charger? Thank you for reading.