HWG&trade; Laptop Replacement Battery (5741-9cell) For Acer Aspire 4000 4551 4551G 4771G 4741 4771 5000 5741 5742 7741 Series Battery type: Li-ion; Voltage: 10.8V; Capacity: 7800mAh; Cells: 9-cell; Color: Black 100% NEW from Manufacturer; Up to 500 recharge cycles over the life of the battery. Grade A Li-ion battery cell; Rigorous quality control; Ensure product safety and stability 24 x 7 email support; 12-month hassle-free warranty Fulfilled by Amazon.