Weird issue with 12V Battery

[goodbadboys9]

I am having weird issue with my car.I am getting error messages if I dont drive the car for a day or so.

Below are the error messages.
Voltage supplied too low
vehicle might shutdown
schedule service immediately

What I noticed is when I park the car my dc-dc converter isnt charging the 12V battery but it is charging the battery when car is on or If I restart the car by disconnect the battery & fireman loop for couple of hours.

Does any one know if 12V battery send signal if it is running low or is there any fuses I can check to see why dc-dc converter isn't charging the battery when car is off

 

[Tam]

...disconnect the battery & fireman loop for couple of hours...

It doesn't sound normal. 12V battery is automatically charged whether you run your car or not and you certainly do not have to disconnect any wire either.

 

[goodbadboys9]

Do we know how frequent does 12v gets charged from dc-dc converter?

I read that there is some switch on MCU in service menu to disable 12V support do you think it might be related to that?

 

[kindred7]

When the car is resting, wake the car with the app and run the hvac for about 1hr.

After that go out to the car and change the wheel configuration in the settings and reset the car, this is a deep reset. Remember to change the wheel configuration graphic back if you like.

See if this solves your problems. If not you need to change your 12v.

 

[goodbadboys9]

Thanks Kindred.Will follow your steps & see how it goes.

I tried to change wheel configuration when I had the errors & errors came right back after reset.

I thought it was 12V battery issue & I put in a new battery to rule it out but I still have the issue

 

[VTompson]

When the car is resting, wake the car with the app and run the hvac for about 1hr.

After that go out to the car and change the wheel configuration in the settings and reset the car, this is a deep reset. Remember to change the wheel configuration graphic back if you like.

See if this solves your problems. If not you need to change your 12v.

hey! what is hvac?

 

[EVortex]

hey! what is hvac?

Heating, ventilation, and air conditioning.

 

[goodbadboys9]

Tried this procedure, I hear contactors closing & when I try to start the car after reset using wheel configuration update got the errors right back

 

[kindred7]

There was a thread here a couple years ago that was about replacing blown fuses in the dc-dc converter, have you checked this out?

 

[Doanster1]

Could be the battery sensor attached to the 12v. Just had mine replaced a couple weeks ago after getting “Power reduced” msgs every so often without any subsequent ill-effects. SC tested everything else, including health of the 12V battery and deemed it good so the sensor must’ve been flaky and sending false readings every so often which triggered the errors.

 

[goodbadboys9]

Might be my issue too.Do you know part number for the battery sensor?

 

[goodbadboys9]

There was a thread here a couple years ago that was about replacing blown fuses in the dc-dc converter, have you checked this out?

I dont think it is blown fuse in DC-DC converter here is my logic & I might be wrong too if fuse is blown it shouldn't charge the battery at all but the battery is being charged when I rest the car or when driving or when charging the car(I mean using wall charger or supercharger)12V Battery isnt getting charged only when car is off(I plugged in aftermarket battery monitor in the afternoon & I haven't seen it charging 12V battery since then)

 

[Doanster1]

Might be my issue too.Do you know part number for the battery sensor?

SENSOR INTELLIGENT BATTERY(6007953)

Reading through the old text exchange with the SC on this, they orig said the sensor reads out values from the DC/DC converter and was passing wrong values every so often. They called the part (multiple times) the 12V sensor though so now I’m curious as to where it actually is so will look it up on EPC later tonight. It was def a Ranger serviceable part so I’m thinking on/around the 12V battery.

 

[goodbadboys9]

SENSOR INTELLIGENT BATTERY(6007953)

Thank you very much for your IM response too

 

[Doanster1]

I was right. Sits on the positive terminal of the 12V battery. Number 14...

 

[goodbadboys9]

I was right. Sits on the positive terminal of the 12V battery. Number 14...

Got it.Thank you very much.Will see if I can take it out & test it anyway

 

[goodbadboys9]

Last night DC-DC converter kicked in & charged the battery but most of the time my battery stays at 12.3-12.7V
I think for Tesla's battery are supposed to be @13.7V right ? or Is it normal for 12V battery to be @12.3V

I attached some of the graphs below & 13.7Voltage until 09:30AM is while charging the car

 

[goodbadboys9]

 

[goodbadboys9]

Seems like DC-DC converter kicked in at midnight. Is there anyway I can test intelligent battery sensor?

 

[Doanster1]

View attachment 604739 View attachment 604738
Seems like DC-DC converter kicked in at midnight. Is there anyway I can test intelligent battery sensor?

Not that I know of, especially as it’s currently not a hard fail condition. If we only had access to the logs...