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12 volt battery warning - rotten egg smell...can I drive it a week?

Tube Guy

Member
Jan 2, 2019
63
17
So Cal
Hi folks

My X has a service appointment in 5 days for another issue. The 12 volt battery warning light came on a few days ago, and now today there is a rotten egg smell. Does anybody have knowledge about this issue?

I have to say getting support from Tesla SUCKS. Nobody to ask. I mean really. I love the car so much but they need to step it up.
 

VikH

Supporting Member
Supporting Member
Nov 23, 2015
1,082
1,025
Midwest, USA
You should get your 12V changed out asap or expect that you may be stranded at any point. The rotten egg smell may be from your A/C.
 

Webeevdrivers

Active Member
Jan 2, 2017
2,365
4,400
Canada
One of your cells in your 12 volt battery has become a dead short. The other 5 cells are now taking the full brunt of the approximate 13.2 volt charge. Instead of each cell getting 2.2 volts they are getting 2.6 volts. The smell is the electrolyte burning off and venting. Get it changed fast.
 

forkee

Member
Jul 20, 2018
776
974
Southern California
i had to wait 2 weeks before coming in for the next available scheduled service and it was intermittently farting in the garage, and it made it fine till i brought it in. but i have heard stories of people coming out to a dead car that they could not even get in, so your experience may vary. the most annoying thing was that i couldn't use summon or update the firmware until the battery was replaced. i would update your service appointment details to add that in there, otherwise they may not have available batteries for you. as of this past monday, SC in buena park is on back order and waiting for a lot of them, so best to notify them ahead of time before bringing it in, otherwise they won't have the part and you will be have to reschedule or wait for mobile tech to come.
 

doghousePVD

My grandfather’s car
Dec 3, 2018
650
600
New England, USA
Rotten egg smell is hydrogen sulfide (H2S) coming from your 12 volt battery. Beside being really stinky, it is very poisonous. You really want to get that battery changed out ASAP. If you are not driving it, disconnect the battery so it does not produce more H2S. Note that disconnecting the 12V will disable sentry, doors, lights, etc.

Hydrogen sulfide from battery charging is pretty rare. It only happens when the charger is way overcharging/too high voltage. As a temporary fix, you probably could stick any 12V battery in order to drive it to the service station. However that battery is likely to be damaged from overcharging, too.

The likelihood of actually getting poisoned is low since it is so smelly. However, it is very difficult to tell the difference between trace quantities (annoying, but not a too serious health issue) and really dangerous amounts. H2S is also very corrosive to metal. see Wet Hydrogen Sulfide (H2S) Cracking

So, beside potentially health issues and severe corrosion to the car, you might also be stranded somewhere.

What hazardous gases are associated with lead acid battery charging stations? | GfG Instrumentation | GfG Instrumentation
 

ajdelange

Active Member
Dec 10, 2018
1,077
638
Virginia/Quebec
The smell is H2S from the battery. Lead acid batteries often give out a slight whiff of H2S (they contain lots of sulfate) but if it is strong something is definitely wrong and you should get it replaced ASAP. In the interim I'd leave the frunk unlatched. This is so that if the battery does go TU you can easily access the jump terminal and get enough DC into the car to open doors, put it in neutral etc.
 

Tube Guy

Member
Jan 2, 2019
63
17
So Cal
i had to wait 2 weeks before coming in for the next available scheduled service and it was intermittently farting in the garage, and it made it fine till i brought it in. but i have heard stories of people coming out to a dead car that they could not even get in, so your experience may vary. the most annoying thing was that i couldn't use summon or update the firmware until the battery was replaced. i would update your service appointment details to add that in there, otherwise they may not have available batteries for you. as of this past monday, SC in buena park is on back order and waiting for a lot of them, so best to notify them ahead of time before bringing it in, otherwise they won't have the part and you will be have to reschedule or wait for mobile tech to come.


We have tried to update it but nobody responds to let us know they read it. It's really horrible.

Now I just looked at my app on my phone. It did show the upcoming appointment. Now it shows NOTHING about it, and doesn't have a button to MAKE an appointment.
 

ElectricLove

Member
May 28, 2013
554
323
If you want a battery right away these guys have them in stock and ship out fast. Also it’s a major upgrade over the lead acid batteries!

www.ohmmu.com

They are Lithium 12V specifically for Teslas.
 

forkee

Member
Jul 20, 2018
776
974
Southern California
We have tried to update it but nobody responds to let us know they read it. It's really horrible.

Now I just looked at my app on my phone. It did show the upcoming appointment. Now it shows NOTHING about it, and doesn't have a button to MAKE an appointment.

check your account online. it should still be there
 

pereiks

Member
Sep 25, 2019
136
36
Sammamish, WA
If you want a battery right away these guys have them in stock and ship out fast. Also it’s a major upgrade over the lead acid batteries!

www.ohmmu.com

They are Lithium 12V specifically for Teslas.

Battery Management System prevents damage to battery in extreme situations and also balances the battery cells to maintain the pack for longer service life!

How safe is to put lithium 12v battery in Tesla? Is it in the right place to prevent damage from overheating? Tesla is using A/C to cool down main battery but not this one.
 

ajdelange

Active Member
Dec 10, 2018
1,077
638
Virginia/Quebec
The pitch from Ohmmu suggests that there is a reasonably sophisticated BMS within the unit. So when the battery gets hot, stop or slow charging it. If the battery is too cold to accept charge at the desired rate turn on an internal heater. The 12V battery doesn't handle traction load or A/C compressor load so it probably isn't going to need cooling. The BMS is certainly sophisticated enough to balance 3 cells.

All speculation here, of course. The site implies these things but stops far short of telling what they are actually doing. As such I'd be interested in hearing from anyone who has had any actual experience with one of these. Handbooks list this chemistry as being good for 5 years but Ohmmu only warrants for 4. ??
 

ajdelange

Active Member
Dec 10, 2018
1,077
638
Virginia/Quebec
We have tried to update it but nobody responds to let us know they read it. It's really horrible.

Now I just looked at my app on my phone. It did show the upcoming appointment. Now it shows NOTHING about it, and doesn't have a button to MAKE an appointment.
Through the app is the only way to make an appointment - if it works. It once took me three days to set one up. The trick was that I had to use a non existent address to get it to accept anything from me.

They removed the ability to make appointment from our on line accounts several months ago nor is there any indication of existing appointments in the online account.

I'd suggest reloading the app and seeing if your existing appointment pops up. If not, I can't think of anything to do except go to the SC or start all over with the app.

Yes, it really is horrible. It is this that I think will be the "Tesla Killer".
 

Black Beauty

Member
Jul 8, 2018
34
19
Chicago Area
I just had this problem and scheduled an appointment. It put me out 2 weeks and my car died yesterday. The fire dept came out to the office because the smell was really strong and someone reported it (I don’t blame them).

I think Tesla should expedite battery issues to avoid cars dying on owners. It seems to be common and getting prompt service is impossible.

The Model X is a premium car. I wish I could say the same about the service.
 
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Reactions: Mjølner

jboy210

Supporting Member
Supporting Member
Dec 2, 2016
5,468
3,468
Northern California
I just had this problem and scheduled an appointment. It put me out 2 weeks and my car died yesterday. The fire dept came out to the office because the smell was really strong and someone reported it (I don’t blame them).

I think Tesla should expedite battery issues to avoid cars dying on owners. It seems to be common and getting prompt service is impossible.

The Model X is a premium car. I wish I could say the same about the service.

Call roadside service since it is a safety item and see if that helps. When I had a flat tire and got the car towed in, service put me at the front of the list because it was a safety item
 

KitCatTe$la7

New Member
Nov 29, 2019
1
0
Usa
Same happened to me. Car lasted about 1 week and then odor started. I thought I had a sewer problem. Finally realized that the rotten egg smell seemed to follow me and found this thread. Called local Tesla service and got right in. Had mobile appt to replace the 12v on 12/4. They said that it’s safe to drive but some have reported that the car dies then has to be towed to service. The problem is that the 12v battery is being over charged.

Hi folks

My X has a service appointment in 5 days for another issue. The 12 volt battery warning light came on a few days ago, and now today there is a rotten egg smell. Does anybody have knowledge about this issue?

I have to say getting support from Tesla SUCKS. Nobody to ask. I mean really. I love the car so much but they need to step it up.
 

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