Lenovo Lenovo – Lenovo AC Replacement Laptop Charger – 20V-4.5A – Rectangular Port

Below are list of compatible HP Laptop Model that fits with the HP 6720S Battery,
Hp 550
Compaq 510, 511, 610
Hp Compaq Business Notebook 6720s
Hp Compaq Business Notebook 6720s/CT
Hp Compaq Business Notebook 6730s
Hp Compaq Business Notebook 6730s/CT
Hp Compaq Business Notebook 6735s
Hp Compaq Business Notebook 6820s
Hp Compaq Business Notebook 6830s

Before using the new replacement HP 6720S battery for the first time, make sure that the battery is fully charged.