I am currently having the same problem with my car. It started in all the snow a couple of weeks ago. we had a flat battery so i jumped it off only for it to go flat again. i fitted a new battery and it went flat again again. i then booked it into a garage and he tested the diagnostics and it came up with the
Tdc/Cam sensor. He cleared the fault and was unable to diagnose the drain on the battery. This is still on going. it still goes flat sometimes a week passes but then it lets you down a couple of times in the same day. I am going to have to bite the bullet eventually and book it into renault and pay £70 plus for them to tell me what is wrong with it. please let me know if you have managed to find the problem on yours. Best Wishes. Sam