I just bought a replacement 36A15Ah Lithium battery off Ebay for my old Oxygen Emate City 2011 bike for £217.90 that came with various bits and pieces including a charger with an EU plug.
I just bought an EU/UK plug adapter, but also have my old charger that I bought as a stand alone item some years ago of Ebay that came with a UK plug. I guess I have two now!