cold start problem with fully charged battery

[omodos]

happy new year to all , ok my battery or drain saga continues...temps out here are what most peope on the forum would class as mild 7c has been the coldest so far....

I thought last nite at 7pm to hook up the ctek under the hood and took it off at 7am this morning....the led on ctek showed green ie fully charged battery.

However it took leaving the key position 1 for 7-10 seconds before the X5 would fire up...this has got me confused....either the ctek is telling me battery is charged and aint or I have some other issue with the X5...any pointers much appreciated.... I know having a 3.0d engine narrows down the feedback I may get but thought I'd try the forum.....