Yesterday morning on my ~25 mile commute, I decided to engage the Max Battery mode now available on my P85D. I had already driven 5 miles up to that point, so the car wasn't completely cold and the outside temperature varied between 61-64 degrees according to the 17” screen. The final 20 miles took a little over half an hour to complete, varying at times from a crawl to 75mph as traffic opened up. The Max Battery indicator displayed ‘preparing…’ throughout a period of 30 minutes and did not show 'Ready' until near the end of my commute where I finally had an opportunity to do a 0-60mph launch. Immediately after that launch, the Max Battery indicator finally showed ‘Ready’. Since I was a couple minutes away from the office at that point, I had no opportunity to really test it out beyond that. Observations: I've seen some folks speculate about Max Battery temp being achievable within a few minutes of hitting the button or alternately by driving around for ~15 minutes, but my experience engaging Max Battery while simultaneously driving still took 30 minutes to achieve optimal temperature, all performed with moderate outside temps. My battery consumption for the full two-way (~50mile) commute on this day (Max Battery mode preparing in one direction only) was 351wh/mile. On similar commutes recently, I’ve tended to average about 310wh/mile over the full 50miles. You can do the math, but it seems like it had a fairly significant impact on energy consumption (though I did do one launch, which probably had some measurable effect on the 50 mile average) It seems that currently Max Battery mode is pretty much useless outside of a scenario where you're going to be doing runs at a drag strip where the outside temp is really low and conditioning the battery this way might give you a few tenths in the 1/4 mile time. Because it takes so long to fully heat the battery, it’s really not even useful as an impromptu launch control or to impress passengers unless you’re willing to drive around with a hot battery, waiting for just that right moment. If the Ludicrous mode upgrade for P85Ds requires Max Battery to be ‘Ready’ for Ludicrous mode to become available (as early indications seem to suggest) then I think I will save my $5k... In fact, I’m not sure why anyone would go for it under these conditions unless you have cash burning a hole in your pocket. Will wait a bit longer to make a final decision here (maybe a software update will improve the situation somewhat), but as it currently stands, I don't think Ludicrous mode is in my future.