Many of us have experienced the dead battery syndrome as a result of someone poking something into the OBD port, whether that be your friendly dealership or the nice state inspection machine looking for emissions compliance (Texas not Cali!).
Symptoms usually indicated by the hazard switch staying lit after ten minutes of the car not going to sleep.

But has anybody just had that happen without OBD interference ? I drove into the office the other day just to round off the wheels and parked up at home as normal. But this morning I noticed the triangle was lit and the battery was pretty much almost gone. The fob wouldn't unlock the door either so had to resort to the manual key. Nice to know the alarm works though ;-)

Attached my charger under the bonnet, waited for it to recharge and then closed her up. Triangle went away after the expected ten minutes and we seem to be all good....

Has the ODB virus mutated ?

 

It’s just likely your battery is on the way out or you have a different source of battery drain

 

Original battery? Borbor may be right. How often do you drive it and what's the average trip length? Could be that it has just drained down over time from not logging enough run time to fully recharge after each start.

 

I experienced a flat battery about a year into ownership for no good reason I could determine (no OBD port use). At the time I didn't know to check the hazard light switch so don't know if it was lit, the first I knew about it was InControl calling me to say the car had reported the battery was flat (it obviously had enough juice to go online). I called Jaguar Assistance and they sent a guy out to get me started - I charged the battery overnght and haven't had any issues since - two plus years and counting. So I'd say it is possible for a module to randomly get stuck on, albeit unusually rare (IME).

 

Actually, I had a door handle that caused a battery drain. My triangle was lit when I parked each night prior to figuring out the issue. So I think it can also indicated a battery drain from another source than the battery being bad.

 

I’ll hope it’s just random insomnia. The car was locked and alarmed but I don’t think bad battery or module drain usually keep the triangle lit. Battery is not the original as it was replaced by the dealership under warranty. I keep it plugged into a CTEK if I’m not going anywhere for a couple of weeks. This past year I really let the side down having only driven about 1500 miles and it’s service time again 😂😂