|Hi Shanghai, the websites you have provided links to, suggest you are in Italy.|
To save money, buy a compatible battery from Ebay or Amazon, using their UK websites. Even with including the postage you will save much.
Assuming you have an original HP/Compaq battery, use the number(s) on it when searching for a compatible one.
Ideally the battery should have the same number of cells (6?).
The amps should be the same or preferably higher.
Please advise back on progress.
Good Luck - Keep us posted. Buon Natale!