how do i make my cigarette lighter live?

I have a 1999 rover 400 series 1600. I have just brought a solar trickle charger with crocodile clips to connect straight to the battery ,or there is another connection to plug into the cigarette lighter if it works when the ignition is turned off. so my question is how can I make it live? ty

from the last news http://ift.tt/1KzCSQ7

via IFTTT