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Issues with my Model S
- Thread starter GJ79
- Start date
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- 12v 12battery Model S
SPXMike
Member
Concur. A driver's side window falling out is unacceptable, especially for a car as pricey as an A8. But an intermittent electrical problem that kills the car dead? That's Russian Roulette every time you leave the driveway.
No I found that I can change my Escort Radar detector to where the display actually shows the 12V system voltage.
Just got another update. The issue did not follow the HVJB to the other vehicle. They are moving on and try the swapping out chargers and see if they would cause it. Vehicle has been in the shop 12 days. It starts to scare the crap out of me knowing the level of technology in this vehicle and how difficult it seems to find a cause of an intermittent issue that renders the vehicle useless when it occurs.
JRP3
Hyperactive Member
Your description of what occurred while supercharging with the 12V dropping so low sounds as if the DC/DC converter is shutting off or being disconnected intermittently, so the 12V system is only running from the 12V battery and being drained down.
The issue occured on both: regular charging and Supercharging. But it only occurs when charging.
yes it dropped within 2 minutes. they are replacing the chargers now. Which I don't really understand cause I thought they were completely bypassed when supercharging.
Yes, strange. Unless somehow chargers could pull a large amount of current on the 12v side. Even if it was charging on AC, the chargers go to the HV pack, not the 12V system.
This is one of those things that will be so obvious when it is found, and probably something small. But finding it...
Would be interested in seeing the voltage at the actual 12v battery terminals when it is dropping. And of course the current, but that's a bit harder. Is there anything that is high current draw on the 12v side? I think it's just lighting and computers.
I guess the 11.9 could just indicate the DC/DC converter turned off. That's still a healthy voltage for a battery. It would drop to that and stabalize.
Have you discussed lemon laws with them? At least it sounds like they are taking it seriously.
JRP3
Hyperactive Member
Sure, I just meant that the reported voltage going down to 11.9V confirms to me that the DC/DC is being taken off line for some reason. I don't know if the DC/DC dropping out is stopping the charge session, or if something else is stopping the charge session and then the DC/DC drops out.
JRP3
Hyperactive Member
I can't answer answer that. I don't hink there is anything using that uses thatmuch 12 volt power. It simply shouldn't do it and I am almost sure its some kind of component that is bad between the DC/DC converter and the chargers.
Yeah I don't think that would fly, also I do believe regardless of the miles that a 2 year old vehicle shouldn't do this. Again I had Kia's that were more reliable. A vehicle in this price range should be reliable, period. That's what I expect when I have a car serviced, otherwise what is the point of the service. We could just wait til it breaks.
JRP3
Hyperactive Member
You'd think, but that doesn't seem to be the way the world works. Higher end vehicles seem to be much less reliable than mid range vehicles such as a Camry or something. Not that I'm suggesting your problem is at all acceptable.
Well, if they sent out a batch of Model 3's with this issue it would be a disaster, so lets hope they use it as an example and get it fixed.
I doubt that the average Model 3 owners wants or expects to pay upwards of 6-8k for new chargers or junction boxes once their car hits 50k miles. 50k miles is nothing nowadays !!!
I monitor mine all the time with the detector. I run 13.6 (usually that low when AC running high) to 13.9
I'm still wondering what caused this issue. First of all we need to suspect DCDC converter. Tesla should try change DCDC before changing out chargers.
That said I still doubt dashcam... is it always on, while vehicle is off? If so can you put some monitoring device like a tester in between to measure amps going into dashcam? Need to find 12V hogging device. Going from 13Vish to 11Vish doesn't seem right. Internal batteries or capacitors inside some connected device become very low resistance?
That said I still doubt dashcam... is it always on, while vehicle is off? If so can you put some monitoring device like a tester in between to measure amps going into dashcam? Need to find 12V hogging device. Going from 13Vish to 11Vish doesn't seem right. Internal batteries or capacitors inside some connected device become very low resistance?
It is not the dashcam, It did also happen when the dash cam was disconnected. And TEsla is not suspecting the dash cam at all otherwise I am sure they would have brought it up. I am suspecting something in the 12 Volt charging circuit. No 12 Volt device would cause a voltage drop that fast under load unless it's some kind of short.
If the 12V low issue occurred when the dashcam is taken off, then it likely be caused by 12V circuit shorting or something like that. Maybe Tesla need to open up and find any suspicious wires or harnesses in 12V circuit. Haven't heard of such 12V issues though in TMC. Hope you and Tesla can resolve this wierd issue.
They did that when the isue initially occured a few months ago. They went through all the harnesses and see if something was damaged there. They now lean more towards a component like the charger shortening the cirquit at certain times. The fact that this only occurs when charging makes me lean towards the charging cirquit too. But this also always happened about 2.5-3 hrs into the charging cycle when the SOC was around 40% or lower when starting to charge (I told them that several times but they seem to ignore my talking) . It seems like Tesla does not have a good way in the shop to charge and discharge the battery for testing. From what I was seeing tehy only charge a few minutes here and there and it sems like they do run the heater in the cra to discharge the battery. You would think they would have some kind of system setup to drain the battery for testing.
