This is a brand new Dell T749D battery.
This T749D battery is rated at 5200 mAh. This is the highest rating available for a 6 cell battery pack. The higher the mAh rating, the longer your battery will run before it needs to be recharged again. There are no compatibility issues if your existing battery is rated at 4400 or 4800 mAh or a lower Whr.
We are a US based business with knowledgeable support staff to assist you before and after the sale. Yes, we have a phone number and real people answer your call! Free technical support is available if you need additional help in diagnosing power problems with your battery, ac power adapter or battery meter software.
All our products carry a full 2 Year warranty and every battery is charged and tested before it ships. We provide a 30 day money back guarantee if you are not completely satisfied.