Testing the health of 12v battery?

[OldPro]

I'm wondering, is there a way to test the health of the 12v battery? Is there something on the display (or should there be) to indicate 12v battery health to avoid
any unexpected "sudden death"?

 

[jjrandorin]

My vehicle has under 6000 miles. I had no issues until I had to park my car at the airport for a week. Not in a covered stall. When returning my battery was very low. I couldn’t update. Numerous alert warnings in car. Tesla service rep said “ it’s about time” and normal to replace the aux. battery at this age. She said if car was driven more the battery would last longer. So a $70 battery ( at a car parts store) will cost me over $ 350.00 to have it replaced at Tesla. So, tell me again on how I’m saving money not having to buy gas???

Unless there is some other problem, you are specifically avoiding talking about, its not $350, or even $200, or even $175. The battery + installation is less than $150 for a model 3. Did you, perhaps, post in the wrong subforum?

You created a new thread in the model 3 subforum, and I merged it with one of the many existing 12v threads. There is no situation in which a model 3 12v battery costs $350 installed by tesla, so what vehicle are you talking about?

 

[CJtes]

Where is the $350 figure coming from, Tesla Service? Battery should be around $85 over-the-counter and $40 or so for mobile service to install.

edit: Is there not a Service Center at 746 Auahi St Honolulu?

Where is the $350 figure coming from, Tesla Service? Battery should be around $85 over-the-counter and $40 or so for mobile service to install.

edit: Is there not a Service Center at 746 Auahi St Honolulu?

Maybe your state is different, but the 12V battery in California is about $85 and labor to install $25-50.

And where can you find a 51R battery with a vent hose port for $70? It's more on the order of $200 (as most of the available ones are AGM). Even a conventional vented battery is well over $100, so Tesla's OEM battery is by far the cheapest option available. You can fault Tesla's parts cost for other items, but their 12V battery really isn't one of them.

How old is your car to need a 12V battery replacement under 6000 miles and not covered under warranty? If you still have warranty, it should be covered under warranty.

Recap update after service completed:

Unless there is some other problem, you are specifically avoiding talking about, its not $350, or even $200, or even $175. The battery + installation is less than $150 for a model 3. Did you, perhaps, post in the wrong subforum?

You created a new thread in the model 3 subforum, and I merged it with one of the many existing 12v threads. There is no situation in which a model 3 12v battery costs $350 installed by tesla, so what vehicle are you talking about?

Recap update after leaving Tesla service center: 2019 model 3 FSD. Under 6000 total miles. Tesla fee for replacing 12 volt aux battery was $85.00 and a labor cost of under $27.00. On invoice, “ ASY,12V BATT AND VENT. PLUG,M3 ( 1129xxxxxx) They thought they would need to replace a inside camera which lead to the higher estimate. There is a well known issue with these aux 12 volt batteries going bad sooner then most would expect. Even talk of maybe replacing these with a lithium battery. When my battery went bad, I couldn't do updates. I started getting all kinds of alert warnings. Will see how this plays out after new battery and software update.

 

[CJtes]

Maybe your state is different, but the 12V battery in California is about $85 and labor to install $25-50.

And where can you find a 51R battery with a vent hose port for $70? It's more on the order of $200 (as most of the available ones are AGM). Even a conventional vented battery is well over $100, so Tesla's OEM battery is by far the cheapest option available. You can fault Tesla's parts cost for other items, but their 12V battery really isn't one of them.

How old is your car to need a 12V battery replacement under 6000 miles and not covered under warranty? If you still have warranty, it should be covered under warranty.

I have updated my issue. To answer your question. I have a 2019 model 3. I was told the warranty for the 12 volt aux battery has expired ( but im still under warranty for the main ( drive harness batteries ). Im assuming the aux battery is just warranted for 2 years?

 

[stopcrazypp]

I have updated my issue. To answer your question. I have a 2019 model 3. I was told the warranty for the 12 volt aux battery has expired ( but im still under warranty for the main ( drive harness batteries ). Im assuming the aux battery is just warranted for 2 years?

It would have been covered under the basic warranty which is 4 years 50k miles (whichever is first), presumably that has expired for you.

Your HV battery is covered under a separate warranty (along with drive unit) 8 years 100k miles for an SR/MR, 120k miles for an LR.

https://www.tesla.com/sites/default/files/downloads/Model_3_New_Vehicle_Limited_Warranty_NA_en.pdf

Ironically driving such low miles wears the LV battery more because you are relying less on the DC-DC converter. Although getting 4 years out of it is still decent.

 

[CJtes]

It would have been covered under the basic warranty which is 4 years 50k miles (whichever is first), presumably that has expired for you.

Your HV battery is covered under a separate warranty (along with drive unit) 8 years 100k miles for an SR/MR, 120k miles for an LR.

https://www.tesla.com/sites/default/files/downloads/Model_3_New_Vehicle_Limited_Warranty_NA_en.pdf

Ironically driving such low miles wears the LV battery more because you are relying less on the DC-DC converter. Although getting 4 years out of it is still decent.

Car purchased April 2019. Im well under the 50k limit. Yes what you stated reaffirms what the Tesla rep said. Driving the car more ( then what I do) actually is better for the 12 volt‘s durability. Thanks

 

[kimwin]

Last I heard, a model 3(and presumably Y) battery of that era was only like $80 at the dealer and another $50 for a service ranger to install.

Can one replace the 12V battery him/her self like replacing battery on an ICE car.

 

[Sophias_dad]

Can one replace the 12V battery him/her self like replacing battery on an ICE car.

Yes, but look for install instructions here on TMC. IIRC you need to power off the car first.

Model 3 Do It Yourself | Tesla

service.tesla.com

 

[RayK]

Yes, there's a specific procedure that should be followed in order to do it safely. I believe it's outlined in the owners manual. It involves disconnecting cables in a certain order, much like an ICE vehicle.

Edit: There's a big connector under the rear passenger seat which must be pulled during the battery swap. This does not exist with an ICE.

 

[Flybyglass]

If you put the car into service mode, looking at the LV battery age it will show Atlas Battery with a "OK" showing. That is about al you can view in advance of a pending failure. Later softwares will flag the screen with a replace message and one may ask show up on your iPhone or Apple watch.