12 volt dead suspect climate control...

[KK2018]

2020 soul ev... got up this morning.. -5c... tried to initiate climate pre heating .. nothing.. dead..not plugged in to charge.

Able to open manually and yes the 12 volt is dead. High voltage unit at 90%... was charged up the other day over night.

Has anyone else had this issue?

Dealer indicated the climate pre heating was draining 12volt and that the short trips under 20k were not enough to charge up the 12 volt.... you would think the 12 volt would also charge up with the main unit, but that is apparently not the case...

Apparently the solutions are plug the car in or turn the car on for an hour or so every few weeks to charge up the 12volt....
... I suppose not using climate preheating feature is an option... :roll:

Curious about other people's experiences/comments

 

[IanL]

The generally disseminated information is that the 12V IS charged at some stage during the main battery charging. If yours does not do that, perhaps there is a defect.

It would be interesting to measure the discharge from the 12V with a clamp meter, during preheating.

 

[notfred]

I suspect you just had a 12V that died by itself. The problem with EVs is that you get no warning if they are going bad. I think your dealer is advising you based on how ICE cars work where the 12V battery gets heavy use starting and doesn't get much chance to charge when driving a short distance at low revs.

Preheating definitely has the main battery relay on, you can hear it deep it when you unplug. I haven't checked, but I believe the DCDC converter is running at that point. You can probably tell from the voltage rather than trying to measure the current, around 13.8V is the 12V battery and around 14.2V is the DCDC converter charging it.

Note that as soon as the DCDC converter is on it can provide full output to drive all the accessories and charge the 12V, unlike an alternator on an ICE which can only provide full output at higher revs.

 

[IanL]

I suspect you just had a 12V that died by itself.

I'd agree, except that one would not expect it to die after two years (or less) in service, especially in an EV.

 

[notfred]

Is the car is being left plugged in all the time when not in use? That can cause the 12V to drain because the computers keep waking up to check if it should be charging / preheating, and because it doesn't need that then it never turns on the power which would recharge the 12V.

 

[KK2018]

Thanks for the comments and ideas.

Since this second gen doesn't require the car to be plugged in for climate to run I don't plug it in unless I'm actually charging.

12v Battery tests:
Car is off ... 12.35v
Car plugged in and charging (stage 2) 14.68
Car off after charge (plugged in/unplugged) 12.38
Car climate on 14.08
Car climate on (plugged in) 14.07
Car running no accessories 14.03
Car running with accessories 14.07

12.46v after the tests with Car turned off, not plugged in

It seems that the changing system for the 12v is working... or at least working at the time of tests...

So I seem to be left with an oddity around the sudden drain related to the 12v. I will have the battery tested but suspect it will be fine...

Based on some of the comments, trip length shouldn't matter as the 12v gets charged up by the main batteries as demonstrated by the test results... seems sufficient to me.

I will have the battery tested but suspect it will be fine... I haven't had a battery fail after a couple years but I have heard it happens. I will go chat with the dealer about this... maybe they have a way to diagnose any power draws that may have occurred when the vehicle was off over night (not plugged in)...

 

[KK2018]

Well no surprise... battery checked out fine by the dealer... no charging issues, no system drain/draws noted by the dealer.

Guess we will have to wait and see when or if it happens again.