TLDNR: assumes the car was left outside with no power at all. In you know, like an airport parking lot.
A week in sub freezing temps not plugged in. This isn’t just your fault it’s actually expected. Your battery heater ran out the battery trying to keep the cells from freezing. Lithium batteries have to remain above freezing so they have heaters. That slush stuff they’re filled with, much like a lead acid battery, can’t be allowed to freeze. Unlike a lead acid battery though they’re NOT acid. There are two types I know of: heat tapes and heat pumps. Pumps are more efficient than tape. A tape heater can eat 1/3rd of your battery on a really cold night. I think you have a heat pump (which is better) if you’re lucky only the 12v battery is hosed. Those are relatively cheap. If you fragged the big one though it will not recharge again. Your car now has a non-rechargable battery. You really just left the thing in an outside parking lot in the winter for a week?! This is as bad as the people who think they can get away with having no charger at all and just hitting superchargers occasionally. That can work if there’s never any cold weather. California, Hawaii, Florida, etc.. Apparently it works as far north as Chicago most of the time. Where I live? No. Get the thing on a flatbed, get it to a heated garage with a charger, (even just a light socket will work. Your car should have come with a charger that does level1) and pray. If you’ve got heat tape your main battery is probably done for. It died a few days after you left it alone outside in winter weather. If you’ve got a heat pump there’s a decent chance. It might have lasted long enough. Another day and it would be dead. Also your 12v battery may be fried too. That will also need charging/replacement. Gas engines have a nearly unique quality. They’re nearly immune to terrestrial levels of cold because gasoline freezes at some ungodly low temperature. Diesel and lithium slurry? Not so much. Even gas cars can have block heaters because if it gets cold enough the oil turns solid and the metal the block is made of shrinks. The darn things can crack
TLDNR: an example of sorts
I grew up with 70’s and 80’s era Volkswagen diesels. Back then there were 2 types of diesel #1 and #2. #2 had less energy in it (so fuel economy was worse) and it was more expensive, BUT it gelled at a much lower temperature. We lived in NorthDakota so we used #2 in the winter and #1 the rest of the year. The gas stations usually took care of the change. One time though my dad bought gas in a place that didn’t and the fuel in the rabbit gelled on a very cold night. We had a garage but it was unheated. My dad took a kerosene powered room heater lit it up, and put it in the garage. Took 3 days to liquify the fuel.
After it was warm enough my dad drove the thing around for a while to empty the tank and got some real #2 in it after which it was fine. Only happened once. You may not be so lucky. If your lithiums froze the battery pack is toast.
In Minnesota you CAN’T just leave your car out forever. Next time leave your car on the charger and take a taxi to the airport. Doesn’t need much. Even a regular light socket will do it. If you can park somewhere where there is power available you can leave your car out overnight for a nearly infinite period. If you don’t, and it’s cold, there is a time limit though. You passed it or you didn’t. I’m not sure. If your car WAS plugged in it’s the 12v though. If your area ever gets snow for more than a day or two you probably need a charger.
My car has never seen a public charger and hopefully never will. Unless I try to take the thing cross country. They cost multiple times what power costs are in my area.
Nice long write up, but you missed a lot of key facts about both the situation and the Nissan Leaf.
1) the Nissan battery heater for the Li battery doesn't turn on until the Battery temp is near 0 deg
2) the outside temp at the airport when this happened was around 32 deg F according to the O.P
3) Leaf traction battery don't use a 3rd of the capacity running the battery heaters.
4) they don't loose there capacity in a week of sitting, Heck I have supercapcitors that will hold their charge longer than that.
5) the traction battery is disconnected when the car is off, no Vampire loads on the traction battery, other than a 4 min charge to the 12 volt every 24 hrs. and the battery heater if the battery temp drops below 0.
The service manual is a long hard read, but much better than making assumptions without looking at the facts. Last time I looked the service manual for 2015 and older could be downloaded for free from the Nico site, I would recommend even if you have a new model to get one and read it.
I know people (or hope anyway) have the best of intentions in helping. However, it doesn't help if the info you are giving is wrong. Like it or not, Nissan built the car and has the best info on it.
All cars sit for over a week at some point in their lives, whether at a dealers lot, the factory lot or when someone goes on vacation, it is expected "use" and not the cause of the traction battery going flat.
Hopefully we will hear back on what the dealer finds. I have a suspicion, but what I think should set a DTC. So far none has been reported. I can rule out things by what has been reported by the owner and what he was able to do with the car before it was towed to the dealer.
This isn't a game where you get a prize for being the 1st one with the right answer, it is someone with a problem that asked for help, guessing is not how you solve something like this. Resolving of the problem starts with a logic tree, with known info and ruling stuff in or out by what can be observed. That which can not be observed directly must be done with DTC and scanners that can look into what is happening or not happening.
Repairing modern equipment has got so much harder in recent years, I have been in the trade (recently retired) for over 50 years, the last 20 or so the pace of difficult to nail down problems has expanded exponentially. It is all too common (and a natural trait of humans) to try and equate back to something in the past. Unfortunately things have changed a lot since then.
I am very interested in what the dealer finds.
