Further to this - guy in a cobblers told us this isnt as simple as it seems and that if you leave it to go completely dead it can override your system. After a quick search on the problem I found some common examples of renault car keys:
"The only problem I have experienced is the KEY FOB, the battery was running
low on the keys fob in both keys, so though I would get them changed, After
paying £10.00 for batteries we go ahead and change them (I Mean how hard can
it be), Once new battery inserted the keys fobs don't work, after an hour or
so changing the battery's around still nothing. I called my main dealer and
they say that if the battery is not re inserted with in 10 seconds the key
resets itself (10 secs how in the hell can you change them within 10 secs),
They told me to take the car in and they would reset the keys for a charge,
So off we go to Renault to reset the keys, paid the charge, to be then told
the keys need to be replaced and also the infra red receptor!!!!!! For a
little cost of £690.00 (gobsmaked). Decided against this and went to a
dealer in the next town whom fiddled with the keys and to my amazement for a
cost of £0 (Zero) the keys were working not one expensive part needed, I
have written this as a major waring do not believe the first thing you hear
from your dealer!!!!!
I had call out yesterday from my wife who couldn't get her Renault Megane
Coupe started outside the school.
It would seem that it was the key that was faulty as it would neither
operate the central locking nor switch off the immobiliser but she used my
key and off she went.
I assumed that it was the battery but I took her key to the local Renault
dealer who told me that it was the key itself that was faulty and needed to
be replaced at a cost of £135.
I asked why the key had suddenly failed and was told that they didn't last
for ever which surprised me as there didn't seem to be any working parts. I
am not particularly technical and wasn't aware that silicon chips wear out
so you learn something new every day.
It would seem sensible to get both keys renewed at the same time and whilst
I'm at it I may as well get the pair of keys for my car renewed too in case
the chip's are wearing out in them too. What a joke"
Anyone on here had problems like this?