Air vent delay

Hello, i have a bit of a strange issue, XF 3.0S Diesel 09 reg, now that the cold weather is here i have noticed when i come out to the car and its cold the engine starts straight away when you push the button but the air vents and radio do not open/ come on for about 30secs i am also unable to move the seat and the heated front screen does not work once she warms up the all goes back to normal except the screen which still does not seem to work, i have checked both fuses and they are fine, if i was to guess its as if the battery isnt holding the charge and once it get a bit of charge from the alternator everything barring the screen fires up, anybody else had any sort of thing like this happening, thanks for the time

steve