Coolgo&reg; New Laptop Battery for HP Compaq HSTNN-IB1A HSTNN-LB1A HSTNN-Q78C HSTNN-Q78C-3 BQ350AA 587706-761 HSTNN-Q78C-4 HSTNN-Q81C HSTNN-Q81C-3 HSTNN-Q81C-4 HSTNN-W79C-5 HSTNN-W79C-7 HSTNN-W80C HSTNN-I86C-3 HSTNN-I86C-4 HSTNN-I86C-5 HSTNN-I85C-3 HSTNN-I85C-4 HSTNN-I85C-5 HSTNN-LB1A 587706-761b320 321 325 326 420 620 621 425 625 4320t 326 420 ProBook 4320s 4321s 4325s 4326s 4420s 4421s 4425s 4520s 4525s 4720s HSTNN-CB1A HSTNN-DB1A HSTNN-CBOX HSTNN-CB1A - 18 Months Warranty [li-ion 6-cell 4400MAH] High-Quality: Our battery choose high quality and new lithium-ion cells, safe and reliable, stable performance which can charge-discharge more than 500-800 cycles. Quality Certication: All the products pass the ISO9001, CE and ROHS, FCC multiple international authentication and completely accord with environmental protection requirement. Consummate Design: Excellent design makes the product not only has the overcharge, discharge and short circuit multiple protection, but also to balance charge-discharge of all the internal cells. Environmental Test: Standard modern assembly line. All products have passed a variety of charge-discharge and aging test before they leave the factory. 100% quality test for all items. Operation time: For standard battery(6-cell, 4400mah): 2-3 hours; for extended battery(12-cell, 8800mah): over 4 hours (Note: The actual operation time depends on how much electricity is required by the device and how you use the battery.)