Hi @ehen
According to p.28 of the [http://h10032.www1.hp.com/ctg/Manual/c04763947.pdf|maintenance and service guide] for the model series, there are two compatible batteries that can be used in the laptop, a 4 cell 41Wh battery - p/n [https://www.google.com/search?client=firefox-b-d&q=752237-001|752237-001] (examples only) and a 3 cell 31Wh battery - p/n [https://www.google.com/search?client=firefox-b-d&q=776622-001|776622-001] (examples only).
Search online for the part number to find suppliers that suit you best.