Still can't comment about automatic functions after 4 days, but regarding other communcations I mentioned previously, perhaps a difference is that my car is almost never locked in the garage and I am guessing it is not locked at the dealership presently.
So, perhaps it is not in the "Guardian" mode. I can see the logic in the car trying to shut down as much as possible to conserve battery if it is parked (at the airport) for 10 days.

 

No need to guess - the remote app should tell you!

 

Ha!!
Just checked -- hood open, unlocked.
Does that mean they are actually working on it??

 

Dunno, but it sounds promising!

 

Next oddity. Yesterday after I got the low battery warning I as usual hooked up the CTEK. Went to disconnect the CTEK today, more than 24 hours later I think, and the CTEK only got to stage 4 in the charging cycle. WTF? Never happened to me before with the F-Type or any other car that a charge took this long. Removed it, reconnected it and switched it to AGM mode in case that would make any difference, but I have charged the battery before both in normal and AGM mode without any issues...

 

Don't know what model CTek you have but if its the really small one and the battery is severely discharged it might take one or two full days to fully charge the battery especially if you have a significant parasitic drain on the battery fighting the charger. Alternatively the battery is just kaput.

For reference I used to use a Battery Tender on my car before I got a large capacity CTek. If the battery was really discharged the BT would take a day and a half to fully charge the battery.

 

Might make sense to give it a full charge with a more powerful unit.
If the battery is not new, you might try to equalize it - there is a CTEK setting for that.
Either way, it sounds like you have current drain going on.

Here is a testing method for parasitic draws:

 

The CTEK charger I have is the MXS 5.0 and it's worked fined over the years with other batteries of similar capacity - two XFs and a BMW. It never took this long to get it fully charged. So it quickly reaches 80% charge which is what stage 4 means but so far hasn't managed to get up to 100%. There was no problem with that the other week when I last charged it. I'm leaving the charger connected until tomorrow to see if it goes beyond stage 4. If it doesn't it's definitely time to let the dealer take a look.

I thought of the few power related mods I did to the car but don't think any of that could cause any power drain. I didn't wire anything in and just changed the mirror indicator lights, footwell lights and puddle lights in the doors. I assume that power to all those lights is cut off when they're not used but is there any possibility that say a failing footwell LED would cause some power drain?

The manual oddly enough states that the battery has to be removed from the car to be charged but we all charge it in the car, usually without any issues. Makes me wonder if the dealer could decline to do any related repairs on warranty because I tried to charge the battery myself without having it removed...

 

I thnk the "remove the battery to charge" is Jaguar covering itself in case you connect a high power charger and it fries modules. The CTEK, as you've found, gives a very gentle charge. It sounds like maybe you have a drain that's just a bit more than the CTEK can overcome.

 

Checked the CTEK again and lo and behold the battery was finally fully charged now. It's all still a bit weird so I'm definitely keeping an eye on this.

 

Yep, that sounds like a good explanation.

 

Back to my original post.

A month later, and no low battery message. I've driven it a bit more, but haven't used the tender. Not sure what's going on, but until it consistently complains, I'm not buying a battery because I'm, a parsimonious SOB.

 

...then lithium is probably not for you :-)

 

Today, 4.5 months after my original post, the battery has met its maker. Got in it this morning to go to the gym and the car would not notice either of the FOBs. I took my wife's car instead. When I got home I measured the battery voltage, around 12.3. Last week it was 12.45. Just for s&g I tried to start it. it fired right off. The charging voltage was about 14.8 - 14.9 which is correct for an AGM. I turned off the car and measured the battery voltage 12.4 and dropping to 12.2. So somewhere between 12.2 and 12.4 is where the electronics decide that they don't want to play.

So a stop at Costco and a new battery is in the trunk of my wife's car waiting for the weather to turn back into spring. (Snowing here today)

 

The Interstate battery that I got at Costco in April failed about a week or so ago. The car still started fine, but I always got the low battery alarm. Battery voltage measured at 12.53V and would not get higher. So today I took it back to Costco and got a replacement. Costco has an interesting approach to replacing batteries under warranty. It should be a free exchange, but their view of free exchange is refund the purchase price and then charge for the new battery which, of course, is more expensive. I asked to see the manager who took the additional charge off. The warranty on the new battery started on the date of purchase of the original battery.

At any rate, the new battery voltage measures 12.73V and I'm sure after being on the tender will get to 12.8V.