AddOn's 312-0749-AA is a Dell compatible LI-ION 9-CELL 11.1V 7800 mAh Notebook Battery for Dell portable computers. This higher-capacity 7800 mAh battery packs more punch than the OEM. It has a similar form factor to the OEM and is made specifically for the Dell series of portable computers. AddOn batteries are 100% tested and compatible for the systems intended for. Battery life depends on many factors including: available DRAM, screen brightness, applications, features, power management, battery condition and other customer preferences. AddOn part numbers mimic the OEM, and are comparable in form factor and battery life.