I agree that cold is not friends to batteries and especially lithium batteries. Tesla cars are equipped with a heater that warms the cells in sub-zero temps as charging Lithium batteries sub 0C is not possible. I'd assume our LiFePO4 (4 for 4 cells) are also equipped with something similar in order to regulate temperature and make sure the battery is nice and cozy warm
but I couldn't find any technical material. Also worth noting, Tesla lithium batteries are liquid cooled by AC coolant lines in high operating temps!
If you check the attached pdf above "LithiumIonInfo", it displays the operating temps, and our batteries shouldn't have trouble down to -25C.
Being curious, I checked some information after I was boosted and drove the car for 45mn at HWY speeds: (but not the closed circuit current monitoring didn't know about it):
Last state of charge findings:
Last: 96%
1 day ago: 90%
2 days ago: 88%
3 days ago: no definitive view possible: No value present, or rest phase too short
4 days ago: 92%
5 days ago: 86%
So based on the above, it seems that everything was fine leading up to that overnight. Maybe the gremlins did something
Charging status histogram: (period w state of charge)
0-40%: 0h
40-55%: 50h
55-70%: 400h
70-85%: 2170h
85-100%: 2700h
However, all this said, I agree with you, better have peace of mind and I will be finally buying the CTEK lithium charger and also the Noco GB-70 portable booster pack. Better be safe and ready than sorry. My brother said just keep calling your free road-side assistance
My prediction: dealer will say we didn't find anything and battery is ok! But I will ask what procedures they did to eliminate alternator fault or at-rest parasitic drain or battery fault..