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

[KenEE]

Visibly? Was the case distorted from heat or something? That would be concerning.

Yes the case was distorted. Wish they were going back in with a Lithium Ion battery. That thing is burried and a LI would last 3-4X longer than lead acid. It would also be much smaller and lighter.

In fact I was thinking since we don't have to crank a starter to turn an ICE you could mount a very small 12V lithium battery right behind the nose cone and just remove the burried lead acid.

 

[lolachampcar]

It would be helpful to know if anyone else can confirm the same failure mode for the 12V battery. If you're having the problem, try to get a look at the battery when they pull it out.

I've not seen a lead acid battery distored before. Has anyone seen this failure mode away from Model S and, if so, what was the cause.

 

[rick325]

I've not seen a lead acid battery distored before. Has anyone seen this failure mode away from Model S and, if so, what was the cause.

I have. My son has a ride-on electric go-kart w/ 4x6V LA batteries. He mistakenly let it overcharge (I think the charger was complicit too, as it should have shut down) and there was a visible distortion of the battery casing on 3 of the 4 cells.

 

[mknox]

Yes the case was distorted.

Wow. That certainly would indicate that these 12v problems have more to do with the charging algorithm than a bad batch of batteries going into the new cars.

 

[MarkR]

I've got the same error message and had a ranger to the house yesterday. He reported that it appears to be a software glitch, but also seemed to confirm that the charging system may be partially responsible. His attempt at a solution: charge overnight in 'range mode' and wait for the next software patch. We will see. As of this morning, I still have the battery error message.

 

[strider]

I just got the 12V battery message this morning. My car was delivered w/ 4.0 so this is not a "pre-4.0" problem. It's a daily driver and standard-mode charged every night.

I drove into work just fine and went out to lunch w/ no problem - message was still there but everything worked. Nervous about going out to the parking lot to find a dead car this evening...

 

[swegman]

Visited the Rockville MD service center today. The techs told me they have been told by the factory that the battery issue is a firmware (not software) issue. They also told me that they have not had to deal with any dead battery (or warning notice) issues with respect to the 12 volt battery. According to them, a 14.5 volt or slightly higher voltage is acceptable when charging.

 

[steve841]

I've got the same error message and had a ranger to the house yesterday. He reported that it appears to be a software glitch, but also seemed to confirm that the charging system may be partially responsible. His attempt at a solution: charge overnight in 'range mode' and wait for the next software patch. We will see. As of this morning, I still have the battery error message.

Don't hold your breath. That didn't work for me. All I can advise is: If you are getting the 12v warning, don't be anywhere you cant leave your car, because total shutdown comes without warning.

 

[FlasherZ]

I just got the 12V battery message this morning. My car was delivered w/ 4.0 so this is not a "pre-4.0" problem. It's a daily driver and standard-mode charged every night.

As I understand it, the fix for the charging system was delivered in v4.1. First, a bad fix in 1.19.27 (that left me unable to charge), then a good fix with 1.19.31.

 

[badgerlake]

As I understand it, the fix for the charging system was delivered in v4.1. First, a bad fix in 1.19.27 (that left me unable to charge), then a good fix with 1.19.31.

The battery message reappeared for me on 1.19.31. Service told me they were aware of this issue and an update is coming soon to address it. Asked if I could safely drive it with this message and was told yes. Awaiting update (4.2?)...

 

[MikeK]

It's crazy that you have a 85kW battery right there that's capable of jump starting and charging the 12V battery, but no way to activate it. It just takes a moment of 12V on the terminals to get the S going under its own power.

They could add a hidden button somewhere to activate the 15V charging momentarily and then you would never be stranded.

Interesting tidbit: The EV-1 had exactly this button. Under the dash, on the right-hand side. I never had to push it, personally.

FlasherZ expressed doubt that such a button was possible if the main contactor was open. I confess that I don't know how the EV-1 implemented this feature.

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I've not seen a lead acid battery distored before. Has anyone seen this failure mode away from Model S and, if so, what was the cause.

I've had AGM lead acid batteries swell and crack open when left to deeply discharge. Happened to the batteries in a UPS that I had in storage, even though the batteries were not actually connected electrically. I had to take the whole bleeping thing apart to get the batteries out and replace them with new ones...

 

[PatP]

Not confirmed if that helps (but pretty confident), but until they correct the 12V battery issues, my trick is to charge the car at very low amps (like 10 amps) so it charges for very long (ex. 12 hours). This way the 12V battery gets charged longer.

 

[lolachampcar]

IF the problem (big IF) is too high a charge voltage from the traction battery when the car is off, then a seperate charger MAY hold the voltage on the system high enough to keep the traction battery charging from coming on. ALL BIG IFs without testing.

 

[dtich]

Not confirmed if that helps (but pretty confident), but until they correct the 12V battery issues, my trick is to charge the car at very low amps (like 10 amps) so it charges for very long (ex. 12 hours). This way the 12V battery gets charged longer.

yeah, i did this too. i went away for 10 days and lowered the charge current to 24 from 40.. for a couple reasons, but one was to make sure the car charged for a while at least every other day rather than big spurts.. made sense to me, we'll see how it works out.

 

[FlasherZ]

Interesting tidbit: The EV-1 had exactly this button. Under the dash, on the right-hand side. I never had to push it, personally.

FlasherZ expressed doubt that such a button was possible if the main contactor was open. I confess that I don't know how the EV-1 implemented this feature.

Sorry, I should have been more clear. You need power of some sort to close an electrically-operated contactor. The EV-1 could very well have had a manual rod that pushed the contactor closed (and you could have that in the model S, too), to provide "jump start juice" to the lower voltage systems. There are lots of ways to design these -- I don't know of the EV-1's systems either...

I've had AGM lead acid batteries swell and crack open when left to deeply discharge. Happened to the batteries in a UPS that I had in storage, even though the batteries were not actually connected electrically. I had to take the whole bleeping thing apart to get the batteries out and replace them with new ones...

The same situation here, although mine was due to a miscalibrated UPS unit -- it charged 12v cells at a voltage that was too high.

 

[MikeK]

I'm pretty sure the EV-1 was not a mechanical link to the main contactor. Now i'm intrigued. Maybe I'll see if I can find out.

 

[tezco]

I'm pretty sure the EV-1 was not a mechanical link to the main contactor. Now i'm intrigued. Maybe I'll see if I can find out.

Might have just been a manual switch in parallel with the contactor. As long as it just powered the 12V battery charging circuit, the contacts wouldn't have to handle a large current load. Or, I suppose it could have powered a small DC to DC converter which in turn would pull down the main contactor.

 

[MikeK]

Might have just been a manual switch in parallel with the contactor. As long as it just powered the 12V battery charging circuit, the contacts wouldn't have to handle a large current load. Or, I suppose it could have powered a small DC to DC converter which in turn would pull down the main contactor.

I chatted with a fellow former EV-1 driver, and he believes that it's pretty similar to what you described -- that the DC-DC converter was not connected through the main contactor, so you could cause it to come on by pressing this hidden button if the 12V was kaput.

 

[strider]

So service had me do a low-amp range charge (they requested 5A but that would have taken 3 days so I did it at 24A), then unplug the car and let it sit for 60 minutes. No dice. Drove back and forth to work without incident. Last night the "Tesla Elves" did some work on my car remotely and now the error is gone. I'll keep my eye on it.

 

[Lloyd]

I got the dreaded 12 volt battery warning this am! Reported to service 14 hours ago, and no response!

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Now I have a tire pressure warning also. I will check them tomorrow, but I suspect that they are correct.