Get from Amazon.com : https://www.amazon.com/gp/product/B005H3CH9W?tag=bromabakery0d-20

Bavvo 12cell Laptop Battery for HP Pavilion DV6780SE DV6775US DV2840SE Compaq Presario

Product Description :
High quality brand-new Li-Ion battery 108v 8800 mAh 12 cells
30-Day Money Back Guarantee 1 Year Warranty
OEM compatible High capacity battery certified by CE and RoHS Guaranteed to meet or exceed OEM specifications
Before purchase please make sure all the technical specifications and the model No match with your laptop battery
If your original battery is a 6-cell battery this 12-cell battery has much higher capacity and works longer hours after each charge However it is bigger heavier and sticks out due to the extra 6 cells It will still fit in your laptop