vampire drain and the 12v battery

[RVD98072]

ok, i'm a pretty new owner so i didn't really know but i left my MX at my work parking structure last week and left town for a week. i didn't leave it plugged in...just wasn't thinking or knew i should do that. i also didn't put the car into low energy mode or anything like that.

i did that because it's a new car and my garage at my townhouse near work is tiny. my townhouse is only a pied-a-terre in the SF bay area but i live in Seattle so i will be flying tomorrow to get the car and drive it home to Seattle.

when i get to the car tomorrow night, i will have been gone for 10 days.

i had around 160 miles of range when i left. i've been checking the app pretty much daily to check on the car and it's been seemingly ok but range is down to about 110 miles now. still plenty of range left before it would go to 0.

my concern now is on the 12v battery. i've been checking the app for car status so i have been waking up the car pretty much daily. i guess the battery is still up and running since the app is able to connect to the car.

i guess my question is how the 12v battery gets charged? am i good since the main battery has enough juice? or can the 12v battery deplete even though the main battery isn't depleted?

should i make sure to stop checking up on the car via the app? i went from checking on the car twice/day or so to checking once/day. i just wanted to make sure that it's still there, not towed, etc.

 

[Solarman004]

12 V battery is charged from the main battery. You will be fine.
Resist the urge to keep checking it and waking it up.
You are correct that in the future if you have a way to keep it plugged in, that would be your best option.

 

[RVD98072]

Ok good. I thought the 12v would be charged from the main battery so if the main battery has charge i should be fine but wanted to make sure.

and yes, in the future i will keep it plugged in when i leave for vacation. i didn't really want to risk it in the parking garage because even though i might have been able to find a parking spot near an outlet, i thought it'd be risky to leave my UMC plugged in like that in case someone decides to steal it, etc.

 

[NHK X]

Don’t think they can steal the UMC when the doors are locked, I think it stays locked in the charge port.

 

[Solarman004]

Don’t think they can steal the UMC when the doors are locked, I think it stays locked in the charge port.

Correct. They can't steal the UMC if the car is locked. But if someone wants to be a jerk, they could unplug it from the wall and steal the 120 V (or 240 V in Europe & Australia) adapter.

 

[RVD98072]

My parking garage isn't that bad for theft so it would probably have been ok but leaving it for 8 days might be a bit much for hogging the outlet as well.

 

[lymex2017]

My MX used to drained about 10 rated miles per day(24 hours) when the firmware was 2017.36, which equivalent to 140Watt of constant power. During that time, I believe that the car is always awake because I got immediate respond whenever I use my phone to check. And the situation is about the same regardless of the 'energy saving' and 'always connected' settings.

After upgraded to 2017.42, things has changed, the draining is very much reduced, sometimes less than one ideal km per day. Here are two screen captures showing drops of only 1 ideal km(about 0.5 rated mile) during 43 hours:


Also, the car seems always on asleep because whenever I use the app, J have to wait about 40 seconds before I can see the display, and the car will fall asleep again after a few minutes.

 

[RVD98072]

I actually had the car in energy saving mode already. It was still draining about 6 miles/day though but I was checking up on the car 1-2X per day.

I'll be sure to keep it plugged in in the future if I'm gone for over a week.