BRTONG Laptop Battery for Dell Latitude E5400 E5410 E5500 E5510 KM668 MT322 RM649 PW640 WU841 Compatible Models: E5400, E5410, E5410, E5500, E5510, E5510, E5400, E5410, E5410, E5500, E5510, E5510, E5400, E5410, E5410, E5500, E5510, E5510 Compatible part number: KM668 KM742 KM752 KM760 KM970 MT186 MT187 MT193 MT196 MT332 RM649 RM656 RM661 RM668 PW640 PW649 PW651 WU841 WU843 WU852 T749D U116D W071D X064D P858D Battery type: Li-ion; Capacity: 5200mAh/58WH; Cells: 6-cell; Voltage: 11.1V Operation time for standard batteries: Around 2.5-3 hours, the actual operation time will depend on how much electricity is required by the device and how you use it Overcharger and Discharger Circuit Protection, CE-/FCC-/RoHS-Certified for safety, About 500 recharge cycles over the life of the battery. 24 x 7 email support, 12-month hassle-free warranty