OK... I found a critical clue in solving the LOW BATTERY problem... the vehicle system is not going to "sleep" or shut down mode at night or during the day. But Ignition OFF power draw from the 12VBattery is worse at night. My 2016 Discovery is having this same problem. Key things I have observed when vehicle is locked, key fob is not near the vehicle, ignition is OFF...1) Yellow LED indicators at door panel Lock/Unlock switches never turn OFF; 2) red Hazzard Lamp triangle illuminates only at night; 3) Instrument Cluster LCD, only at night, turn ON for 5 seconds, OFF for maybe 1 second displays only "PARK" in upper right corner... the power of the LCD sucks the 12V battery down until Low Voltage Inhibit occurs then cycling stops .. hence we are all greet with a Low Battery message when we return in the morning. 4) I noticed that when doors are locked if one lifts the door handle, the instrument cluster does not wake up and display the mileage like other vehicles. OK by now you might have guessed, I'm an engineer. I hope the fellows at the JLR dealer relay this info the JLR software people. I know an collegue at JLR, but I haven't seen or heard from him in >7 years... I'll try to email him tonight.