Find powerful battery for Samsung NT-N150

Hello

I am looking for a powerful (> 4400mAh) battery for my Samsung NP-N150. The reason for this is that My IPC laptop can charge the battery on AC power only up to about 20% and

only very slowly. The unit is about 4 years old.

So far I've found some links:

http://www.pcbateria.es/samsung-np-n150.html

http://www.bateriabaratos.com/samsung-np-n150.html

http://www.elecachat.fr/samsung-n150.html

Unfortunately there were no hits at Samsung NP-N150.

Now my questions:
First Do you know where to find some perhaps such a battery?
Second Would you in the above shops to buy something?

greeting