Hello Jay,
Thank you for your interest. Yes, I had read many articles and can confirm that I had taken the necessary actions to ensure that the SP4 was truly/fully powered down. It did/does not drain fully overnight, but from 100% charge it would lose between 20% and 30% overnight. I would log on the next day just to confirm the battery charge percentage and then fully power down again - the result being another 20% - 30% being 'discharged' overnight.
When the SP4 is being used on battery the battery life is good.
There must be a solution to this. Apart from this fault I love my SP4 - but it really is a big usability issue. Are there any reports such as Battery or Other that you would like me to make available to you? If you want to arrange the courier I would be willing to hand over the SP4 for a period of time to help identify the issue...
Regards,
Mark