Dtk 9 Cells High capacity Laptop Notebook battery for Dell Latitude E5420 E5430 E5530 E6420 E6430 E6520 E6530 Inspiron 4420 5420 5425 7420 7520 4720 5720 M421R M521R N4420 N4720 N5420 N5720 N7420 Vostro 3460 3560 Series T54fj [ 9-cell 11.1v 7800mah ] The battery is biggest capacity .So its relatively large size .If you use this battery,can not be used docking station. Battery type: Li-ion; Capacity: 7800mAh; Cells: 9-cell; Voltage: 11.1V. Grade A cells ensure fast charges and low power consumption; Built-in circuit protection ensures both safety and stability. Brand new from Manufacturer. Up to 500 recharge cycles over the life of the battery. Operation time for standard batteries(9-cell, 7800mah): Around 3 hours, the actual operation time will depend on how much electricity is required by the device and how you use it. overheating protection overcurrent protection overvoltage protection overcharge protection over discharge protection short circuit protection