Battery type: Li-ion; Capacity: 2600mAh; Cells: 4-cell; Voltage: 14.8V. Compatible Models: D550 X451 X451C X451CA X45Li9C X45li9c X551 X551C X551CA X551CA-0051A2117U X551CA-DH21 X551CA-SX024H X551CA-SX029H X551MA Compatible Part Numbers: 0B110-00250000 0B110-00250100 0B110-00250100M 0B110-00250600 A31LJ91 A31N1319 A41 A41N1308 CKSE14122 Operation time for standard batteries(4-cell, 2600mah): Around 1.5 hours, the actual operation time will depend on how much electricity is required by the device and how you use it. 24 x 7 email support, 12-month hassle-free warranty. All DTK batteries are UL/CE-/FCC-/RoHS certified for safety and packed with a variety of safety features, including short circuit, overheat, and overload protections.Strict guidelines for compatibility, and standards compliance for environment safety.Grade A cells ensure fast charges and low power consumption; Built-in circuit protection ensures both safety and stability.