I'm just about to take delivery of my PHEV. I'll get a fast-charge point installed hopefully soon, but when I'm charging from a domestic 13 amp socket, either at home or if I'm visiting friends say, who may not have a conveniently close 13 amp plug socket, can I use a suitably-rated (i.e. full 13 amp) heavy-duty extension cable? Is it safe? Is the answer different if it's rainy? I've seen what appear to be pictures of extension cables in use in the Netherlands but I've also seen people like Source London saying you should never use an extension cable. Would welcome people's comments.