Red cross near battery meter

Hi, 

I have a Dell Precision M6600 and I just installed a new battery. It all seemed fine a couple of hours ago, but now there is a red cross sign next to the battery icon and the power is dropping fast. It displays this even when fully charged. The battery seems to be genuine, it was bought from a trust worthy retailer. 

I would very much appreciate any advice on how to deal with this. 

Thank you, 

Andrei