XPS l701x 150 genuine adapter: can anyone tell me the exact model?

Hi guys,

I've recently purchased a l701x with a non genuine adapter. The laptop recognize the battery, but it doesn't charge it, due to the fact that it is a 90w adapter (and not genuine). I believe my laptop doesn't work at the full speed, too.

Now I don't know if the battery that I have is broken, or if it doesn't charge because of the ac adapter.

I'm looking for a genuine l701x adapter, but I've found tons of models out there (pa-15. pa-5m10, just two examples), but I want to purchase (better if used!) THE 150w original model. So I can understand if my battery works or not.

Can anyone please tell me the exact genuine model that Dell sold with 150w xps l701x, the one with nVida GT445M with 3gb of RAM? 

Thank in advance!