TLC&reg; 5200mah 11.1V High Performance Battery for Studio Dell Studio 1555 1535 1537 - 12 Months Warranty Battery type: Li-ion; Capacity: 5200mAh/58WH; Cells: 6-cell; Voltage: 11.1V; 100% brand new from manufacturer. Under 100% Aging Test. Up to 500 cycles life, low self-discharge, no memory effect; Dual IC chips provide protection against short circuit, over-discharge, overcurrent. CE/FCC/RoHS certified for product safety. 24/7 email support, 12-month hassle-free warranty. Grade A Cell ensures fast charging and low power consumption; Built-in circuit protection ensures both safety and stability. Operation time for standard batteries(6-Cell, 4400mAh): Around 2 hours, the actual operation time will depend on how much electricity is required by the device and how you use it.