Dr. Battery Green Series Laptop / Notebook Battery Replacement for Acer Aspire 5536-5883 (4400 mAh) 30-Day Money Back Guarantee. 3 Years Warranty Type: Dr. Battery 10.8 Volt Li-ion Green Series Laptop Battery Capacity: 4400 mAh Condition: New 30-Day Money Back Guarantee. 3 Years Warranty 1000+ charge cycles, with Boston Power Sonata 4400 Cell