Hipower 9 Cell Laptop Battery For HP Probook 4330S, 4331S, 4335S, 4336S, 4440S, 4441S, 4446S, 4530S, 4535S, 4540S, 4545S, 633809-001, PR09 Laptop Notebook Computers Battery Cells: 9 Cells Output Voltage: 10.8V Capacity: 6600mAh; 72Wh