12V battery issues (error messages/car charging problems)

[JRP3]

They certainly do have a DC/DC converter that takes pack voltage down to 12V. The question is does it have 2 channels, as I expect, one keeping the 12V battery charged for essential circuits and the other that runs all the other 12V accessories independent of the 12V battery.

 

[StephenM]

Add me to the list of the stranded due to 12v battery

Got in the car. Warnings on the dash and the display screen about imminent shut down due to low 12v battery.

I still love my MS, but the honeymoon is over :crying:

 

[jomo25]

Got in the car. Warnings on the dash and the display screen about imminent shut down due to low 12v battery.

I still love my MS, but the honeymoon is over :crying:

Sorry to hear it. What firmware are you running?

It would be helpful for anyone posting about issues to note the firmware they are running.

 

[StephenM]

The latest one that was available to me, which was 4.3 I believe. Car was at about 200 miles of rated charge and was sitting overnight. When I got into it this afternoon to drive it had 4 messages all related to the 12v battery and within 1 minute everything went black and the drivers side window automatically rolled down.

 

[Al Sherman]

Sorry about this Stephen. Please let us know what's going on. Where is the car? Where is it going? Is someone coming to you? Is there towing involved? What specifically are they doing to the car?

I just went through this a couple of weeks ago. I never got the battery warnings though. Mine went black during the update to 4.4. My SC is convinced that there was a bad batch of 12 volts. I wonder if it was something to do with 4.3?

The car has worked for the last 300 miles and I bought a 12 volt tester. I've been plugging it in randomly and haven't seen less than 13.4v.

BTW, the "honeymoon"just picks up where it left off. I'm still looking for excuses to drive the car! Please keep us updated.

 

[StephenM]

Sorry about this Stephen. Please let us know what's going on. Where is the car? Where is it going? Is someone coming to you? Is there towing involved? What specifically are they doing to the car?

I just went through this a couple of weeks ago. I never got the battery warnings though. Mine went black during the update to 4.4. My SC is convinced that there was a bad batch of 12 volts. I wonder if it was something to do with 4.3?

The car has worked for the last 300 miles and I bought a 12 volt tester. I've been plugging it in randomly and haven't seen less than 13.4v.

BTW, the "honeymoon"just picks up where it left off. I'm still looking for excuses to drive the car! Please keep us updated.

Thanks Al. I was fortunate it happened in my garage, though it did ruin my plans to pick up some friends and go see Iron Man 3 on my day off :-/
What makes it worse is these friends are real gear heads and they were saying to get a Skyline GTR for this kind of money, and now I had to let them know my brand new car stranded me at home.

The local service rep is coming by my house tomorrow morning, so hopefully he can sort it out without having to flatbed it to the service center. I'm not sure what he's planning to do but I'll keep you posted.

 

[Al Sherman]

Thanks Al. I was fortunate it happened in my garage, though it did ruin my plans to pick up some friends and go see Iron Man 3 on my day off :-/
What makes it worse is these friends are real gear heads and they were saying to get a Skyline GTR for this kind of money, and now I had to let them know my brand new car stranded me at home.

The local service rep is coming by my house tomorrow morning, so hopefully he can sort it out without having to flatbed it to the service center. I'm not sure what he's planning to do but I'll keep you posted.

Trust me, I got abused badly at the golf course when I showed up with my 1996 Dodge Ram. Though to be fair, I may have been a LITTLE more obnoxious than you about my 2013 COTY with my skeptical golf buddies.

In my case, they got the car going with the new 12 volt but wanted to do a lot more diagnostics too make sure it was just a bad 12 volt and nothing else.

Very interested to hear of your progress.

 

[PatP]

Quick update everyone. After two dead 12V battery episodes, I finally got my car back.

Very long story short, they tried to find the problem without success so they replaced the whole battery pack!

I trust this replacement but I now have a permanent cigarette lighter digital voltmeter as a safety measure.

I guess my case was pretty unique.

 

[JRP3]

Could anyone pop the nose cone off and put a volt meter on the 12V posts and compare to the cigarette lighter voltage to see if they are in fact on the same circuit? Might need to put a load on, like maybe the headlights, to see if voltage changes on one or the other.

 

[MichaelS]

The Model S has only one 12V system. So yes, it is the same voltage except that the power socket is controlled by the car.

Could anyone pop the nose cone off and put a volt meter on the 12V posts and compare to the cigarette lighter voltage to see if they are in fact on the same circuit? Might need to put a load on, like maybe the headlights, to see if voltage changes on one or the other.

 

[jomo25]

Quick update everyone. After two dead 12V battery episodes, I finally got my car back.

Very long story short, they tried to find the problem without success so they replaced the whole battery pack!

I trust this replacement but I now have a permanent cigarette lighter digital voltmeter as a safety measure.

I guess my case was pretty unique.

For clarity, they replaced the 12V, not the 85kWh traction battery, right?

 

[JRP3]

MichaelS,

Are you sure? I believe the 12V battery circuit is separate and isolated from most of the 12V accessory circuits, with two channels in the DC/DC converter.

 

[SUN-day Driver]

Question about the 12V battery:

Because I can't always predict commute times I often arrive early and on such days like to sit in my car listening to the radio. I know in an ICE this is a bad idea as tha battery can run down and then not start the car, so I have an MP3 player with FM so I can have the car completely off and still listen for, say 30 mins if I have that much time.

In the Model S is this an issue? Since the main battery will charge the 12V, if the main battery has plenty of charge is it safe for me to sit with the radio on for long stretches every day? Or is this a recipe for getting stranded?

 

[Doug_G]

Had a Ranger drop by yesterday to fix some nits. While here he checked whether my 12V system had the latest firmware. He said it was old, so he updated it. Haven't had any trouble with it... that I know of!

 

[StephenM]

Update on my situation. Our local service rep, Barry, came to my house and brought a fresh 12V battery. I watched, and assisted to a very limited degree by holding the flashlight and putting the panels he was removing aside as he went to work. I was shocked with how many things you have to do to get to the battery. It is absolutely buried in the car, and a weekend wrencher could do it, but it would take a very long time indeed for a first-timer. He had some really long socket extenders too, so not sure if an average tool box would be able to tackle this. He said he has already had to change a few of these batteries out for other cars so he's got the system down, and it still took him 30-40 minutes. I'm sure it would have taken me 2+ hours.
End result, everything works now. Drove it to work, everything normal. When I left work at 11 p.m. the dreaded message came back. Car needs service. Immediately pull over to the side of the road as it may suddenly shut down. This was on the screen for about 10 seconds and went away. I ventured to get home and it was alright, though I was worried. This is the same pattern that happened right before my car died the last time. I checked it this morning to see if the message came back, but it did not. I left a message for Barry that this message came back, and went away, just to be prudent. Crossing fingers that the message last night was some leftover anomaly from the problems in the system, but I'm kinda doubting it.

I hope they hurry up and get those P85/Roadster loaners out to Hawaii so I can have some peace of mind that I'll have a TESLA to drive if my car needs to go under the knife :biggrin:
Heck, it would almost be welcome to have a problem if I had a chance to drive a roadster, though it's highly unlikely that we'll have a roadster to borrow.
I happen to see an orange one yesterday on the way to work and had to snap a pic with it. It looks like a little toy car next to the MS. I would LOVE to swap rides! I should have put a note on that guys windshield :smile:

- - - Updated - - -

 

[MichaelS]

No, not 100% sure, but from a technical standpoint it does not make sense to have two 12VDC channels, one to run the car and one to charge the battery. The two have to be tied together eventually so the battery can run the car. But, if someone has evidence to the contrary, I stand corrected.

MichaelS,

Are you sure? I believe the 12V battery circuit is separate and isolated from most of the 12V accessory circuits, with two channels in the DC/DC converter.

- - - Updated - - -

Absolutely. You will not run down the battery if you sit in the car and listen to music. The additional current draw is very low on the 12V and the traction battery will keep it charged. With a 60 kWh pack, you could sit in the car for over 500 hours listening to music before the car traction battery would run out of energy.

Even running a radio in an ICE is not a problem because of the low power draw of the radio. Many years ago you could run the battery down quickly because the old car radios used tubes which sucked a lot of power. (Am I dating myself?)

Question about the 12V battery:

Because I can't always predict commute times I often arrive early and on such days like to sit in my car listening to the radio. I know in an ICE this is a bad idea as tha battery can run down and then not start the car, so I have an MP3 player with FM so I can have the car completely off and still listen for, say 30 mins if I have that much time.

In the Model S is this an issue? Since the main battery will charge the 12V, if the main battery has plenty of charge is it safe for me to sit with the radio on for long stretches every day? Or is this a recipe for getting stranded?

 

[PatP]

For clarity, they replaced the 12V, not the 85kWh traction battery, right?

No, the 12V has already been replaced without succes. They replaced the 85kwh battery pack!

 

[StephenM]

Absolutely. You will not run down the battery if you sit in the car and listen to music. The additional current draw is very low on the 12V and the traction battery will keep it charged. With a 60 kWh pack, you could sit in the car for over 500 hours listening to music before the car traction battery would run out of energy.

Even running a radio in an ICE is not a problem because of the low power draw of the radio. Many years ago you could run the battery down quickly because the old car radios used tubes which sucked a lot of power. (Am I dating myself?)

Umm, this was not true with my 2010 BMW. By the end of my 3 year lease, if I shut the engine off and tried to listen to the radio for even 1 minute it would flash the low battery symbol and shut everything down. I took it in to change the battery out due to warranty and they said it's normal "because modern cars have many sub-systems running even when you're in accessory mode and draws a lot of power from the battery". I never had that problem with my Honda and could listen on acc mode as long as I wanted, so seems like regress.

 

[MichaelS]

Sounds like something was wrong with the car. If you have a 100 amp hour battery and you only draw .5 amps from it, it should last about 200 hours.

You mentioned at the end of a three year lease, sounds like it didn't do that at the beginning. I think the battery was bad, or there was a problem with the charging system in the car.

Umm, this was not true with my 2010 BMW. By the end of my 3 year lease, if I shut the engine off and tried to listen to the radio for even 1 minute it would flash the low battery symbol and shut everything down. I took it in to change the battery out due to warranty and they said it's normal "because modern cars have many sub-systems running even when you're in accessory mode and draws a lot of power from the battery". I never had that problem with my Honda and could listen on acc mode as long as I wanted, so seems like regress.

 

[JRP3]

No, not 100% sure, but from a technical standpoint it does not make sense to have two 12VDC channels, one to run the car and one to charge the battery. The two have to be tied together eventually so the battery can run the car. But, if someone has evidence to the contrary, I stand corrected.

The Roadster had a two channel DC/DC converter, and I think the 12V only needs to be online to initially boot up the car, especially after sleep mode, when most other functions are shut down.

Umm, this was not true with my 2010 BMW. By the end of my 3 year lease, if I shut the engine off and tried to listen to the radio for even 1 minute it would flash the low battery symbol and shut everything down. I took it in to change the battery out due to warranty and they said it's normal "because modern cars have many sub-systems running even when you're in accessory mode and draws a lot of power from the battery". I never had that problem with my Honda and could listen on acc mode as long as I wanted, so seems like regress.

As I recall BMW has had a major 12V problem, especially if you take short trips, which leads to constant undercharging of the battery, and then sulfation. No radio should kill a battery after 1 minute. If the car sub systems were draining the battery so much that the small load from the radio prevented it from starting after one minute then the battery wouldn't have enough power to start the car even if you didn't use the radio.