My mum has an A8 that she doesn't use much. It has ended up with the battery going completely flat. Her key stuck in the ignition, but I managed to get it out with the little button thing. I have tried to jump start it with my powerpack attached to the battery but I am having no luck at all - not sure whether it is too flat or what. I have a small battery charger but it is no good for the 3l V6. Before she joins the AA and gets homestart, any suggestions as to how to get it going?