Ignition key works poorly.

[007 Mondeo]

Good morning, I had a problem with the ignition key opening and closing the door and the boot. I changed the battery and it was a kit better. finally took it all apart , watched u tube video and had it tested, now works  a lot better. I was told not to use cheap batteries also + has to be in line with key not off at an angle.  Has any one else had this problem?