An update.

Returned from vacation a few days ago and started troubleshooting the re-emerging no start problem. Checked the battery and voltage was fine but nothing was getting to dash, interior lights and it wouldn't crank.

This is a case where I couldn't find the a cause for the particular symptoms I was having and troubleshooting was getting me nowhere. Since the symptoms were closest to a bad ignition switch I replaced the switch. That fixed the problem. So I had a bad battery and a string of bad replacement batteries and a failing ignition switch just to make things more interesting.

FYI- I took the switch apart to see how it works and perhaps fix it. There is a plastic cylinder with ramps in various locations. There are 3 sets of points on either side of where the cylinder rotates. Depending on the position of the cylinder a particular set or sets of points are open or closed. Select points are open or closed depending on position of the key-opening or closing a circuit. The ramps are plastic and the points are metal. Since the ramps are the logical wear point any possible repair didn't make sense.

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X5 4.6 2002 Black Sap, Black interior. 2013 X5M Melbourne Red, Bamboo interior
Dallas