Our route to Wandsworth (when headed for A3 to parents) is Camberwell, Oval, Vauxhall, head for Battersea, past power station, keep going, head for Wandsworth roundabout. Common just up from there. Traffic can of course vary and never done it at that time. Takes 30 mins ish? Prefer this to South Circular, Clapham and C Junct routes.