This word comes from little England, where there is a place called Battersea Dogs Home. Used when one sees a dog-ugly girl.
English Chav 1: Brair, check out that biatch over there! (forgets to breathe and asphyxiates)
English Chav 2: Yeah, blad! She's from Battersea!
Battersea is a small section of London, England that is home to the world renowned Battersea Dogs Home as well as the Battersea Power Station (made famous by Pink Floyd's album cover for their concept album "Animals")
The iconic Battersea Power Station has been decommissioned for quite some time now and is available for about 735,000,000 USD.
Do you know where we are?
Yeah, dude, we've just exited downtown London. We're in Battersea.