Hi Jud1
thanks for your reply.
Yes the immob was off. the first time the car has started, the second time the starter was a little slow and third time the lights of the dashboard stopped (battery was at 8volts after the third try).
I was thinking to charge the battery but when i have seen it, i have noticed it's a very small one, and the power of this battery sounds very low compared to the one used by other forum members (i had a look at each of the 22 pages of this technical jdm forum)
I have taken few pictures this morning.
The current battery:
http://image.noelshack.com/fichiers/2015/10/1425631507-img-0449.jpg
http://image.noelshack.com/fichiers/2015/10/1425631514-img-0451.jpg
But thanks for your advice, i will try to install the battery this weekend, i was wondering if the windows were going down with the key or not.
I was thinking, with the central locking system, maybe the vehicle needs power everytime to not loose the key data.
About changing my battery for an uk version, it's something i'm considering but i don't know which model i should buy and which terminal converter i should buy.
Also i have taken a picture of the hood locking system
http://image.noelshack.com/fichiers/2015/10/1425631525-img-0450.jpg
i have checked this morning , there is nothing blocking it, i will try to use some wd40 on the mecanism tomorrow