It finally happened to me, but it was my own dumbass fault!
I'm kicking myself because I've had
zero issues with the car so far. I hope the flat battery isn't going to be start of any problems, because it's entirely self inflicted.
We had one of those weird overcast days today that's sort of dark enough for the auto lights to have the DRLs on, but not dark enough for it to put the full headlights and tail lights on. It's a legal requirement in Iceland to drive with your headlights on all the time, so I flicked them on.
Usually when I park the car, I don't switch it off. I just get out, the car senses the key is gone, and I lock it, which causes it to turn off itself. The headlights are on a fifteen second timer, and go out when I walk away, so I never check that the lights have gone off. I'm one of those people who always has the key in their pocket, and has the "start on arse detection" option switched on, so I never really usually interact with the key for the car much. I often even just use the touch sensor on the doorhandle to lock it before walking away.
Today I forgot to turn the lights off before getting out, and because I don't turn the car off before doing so, I didn't get the audio ping to warn me that the lights were still on when when I opened the door. I always usually drive with the front fogs on too out of habit because of shit visibility over here, so they were also left on to add to the battery draw. Bugger.
About six hours later, my boyfriend came home from work, pulled in, and when he came into the apartment he said "Your car's lit up like a schizophrenic Christmas tree and the blinkers and tail lights are going mental."
I hadn't remembered that I'd left the lights on, so I was super confused. Went downstairs, and was confronted with the back end of the car doing this:
The car was nosy parked against the wall, and the front lights were doing the same, as well as the side repeaters on the cameras.
Car would not respond to the keyfob, and of course, I started flapping because even with a flat battery on god knows how many other cars I've owned, I've never seen the lights behave like this. Super weird.
Unlocked the driver's door with the manual key, and
super carefully opened it to stop the window fucking up the a-pillar, and the car wouldn't power on. Weird rapid chattering and clicking coming from under the dash, and the same from somewhere in the boot - which I remembered other people mentioning when their batteries went flat.
I had a spare battery from my old Subaru Legacy that I also run, so I hooked this up with jump leads, and immediately the car starts up when I push the button. Horn starts blaring, blinkers and headlights are going, full alarm mode. Easily silenced with the fob by hitting the door unlock button. Pretty much every warning on the dashboard known to man, but as soon as I power the car off, then on again, they all clear and the dash is all good and green.
Seems the random clicking noises people were hearing were coming from the car's alarm system, with it trying to activate the horn and lights when the battery runs down, but not having enough power to do so. Strange, because I didn't think my car had the alarm, given none sold in Iceland have the option by the map lights to turn it off. Seems that every e comes with an alarm, just in some areas not the ability to disable the ultrasonics inside the car. This must be a regional thing I guess, maybe there's some legislation for it in certain territories or something.
So yeah, plugged the driver's side seatbelt in with the car powered on and left it for thirty minutes. Multimeter across the battery with the car turned off after this and it's a good 12.8v. I don't trust it though.
It's lasted all winter just fine, but after hearing the horror stories of how the factory Panasonic battery is garbage and performs super badly, becoming unreliable after just one discharge, I'm gonna pick up the YUASA replacement tomorrow just to be on the safe side.
Lesson learned - don't rely on anything being automatic - check your lights before you get out