FWIW I've been monitoring our new (build date 8/4/09) X5 35d's voltage after sitting overnight. And guess what, I have NEVER seen a voltage above 12.45v. Just now it was 12.33v. This is on a brand new 35d which is commonly driven 25-50mi (one way) into the nearest larger towns. But occasionally only 3-5mi (one way) to the local village.

By way of comparison, there's the voltage on our ranch truck today -- 12.45v. The last time I drove it was about a week ago. OBTW the ranch truck is over 20 year's old, and is only RARELY driven during the summer (no AC and 105 degrees). A very busy week for the ranch truck would include a couple of 3-5 mi trips (one way). Many weeks it isn't driven at all. It hasn't seen a trip of 25 miles, or more, in months.

IMHO BMW is being disingenuous about the low voltage issue(s) on E70s. The "you don't drive it enough" story is simply a dealer excuse for a fairly serious design/implementation flaw on these overly complicated electronic juice hogs.

Funf Dreisig