I have a Roomba 2.1. I love it! I recently replaced the battery. When I received it, I charged it over night. In the morning the light was green so I proceeded to use it. It would not work. I put it back in the docking station and the light was red? What now? What can be possibly wrong with replacement battery for my Roomba 2.1? What can I do about it? I would really appreciate some useful information from your side. Thanks.