I used a Source London card today and took a very brief charge from the 7kw point at South Woodham Ferrers station. Curiously, Source East don't list that charger, nor those at Wickford or Witham stations, as theirs. My Plugged-in Midlands card worked on it as well, but not the CYC or the Ecotricity cards, although I am sure that they used to. Source London don't list them either.
Al those points are marked on Chargemaster's map.
Al those points are marked on Chargemaster's map.