12 volt battery

[RidgeRunner]

Are there any subtle signs the 12 volt battery is losing its capacity. My concern is that we have to ride the ferry twice per week and it is about 30 minutes each way. So, there may be longer duration of load on the battery running HVAC, radio, seat heat, screen than the normal user doesn't get.

 

[canadianeh]

Well my 12 volt DIED at 15 months old.
2022 Model Y performance.
I had 10 minutes of warning, first a message like "electrical system unable to support all features"
Followed by "pull over safely" Vehicle shutting down.
And it did.
A little more advance notice would have been great!

The unfortunate reality is batteries sometimes fail all at once, as oppsed to a slow degradation which can be tracked. It is my understanding that a Tesla needs the 12V battery when awake to manage large changes in low-voltage power demands. So without it the car shuts down.

Given both of these messages, is it worth proactively changing the 12V battery!? My car is at 55K, no changes or problems except for failure of one of the oil pumps and wire harnesses.

 

[fiehlsport]

Given both of these messages, is it worth proactively changing the 12V battery!? My car is at 55K, no changes or problems except for failure of one of the oil pumps and wire harnesses.

It's better to maintain the battery by charging it to 100% on a high quality battery charger a few times a year. This extends the life of lead acid batteries significantly.

Normally a good interval for cold climates is 4-6 years though, even if the battery hasn't failed yet.

 

[jcanoe]

Given both of these messages, is it worth proactively changing the 12V battery!? My car is at 55K, no changes or problems except for failure of one of the oil pumps and wire harnesses.

That depends on your tolerance for being inconvenienced by a failed 12V battery. You can carry a small lithium jump starter (these start at ~$60 USD) in the frunk. You would be able to jump start the Tesla Model Y (boot up the computers) once you are able to open the frunk to access the 12V battery and use the jump starter. (You could use a small 9V battery or A23 12V battery to release the hood.) Some Tesla OE 12V batteries fail within the first year or so while others last longer than 4 years (the basic Tesla warranty period.)

 

[Eric33432]

Well my 12 volt DIED at 15 months old.
2022 Model Y performance.
I had 10 minutes of warning, first a message like "electrical system unable to support all features"
Followed by "pull over safely" Vehicle shutting down.
And it did.
A little more advance notice would have been great!

Was this a Li-Ion 15 volt battery? I thought Tesla changed the LV battery to Li-Ion in 2020 or 2021. My 2022 Model X has a Li-Ion LV battery.

If this was the Li-Ion LV battery it is the first time I have heard of one of these failing.

 

[Occhis]

Replacement 12v cost is around $100 from Tesla. At 55K probably worth replacing sooner rather than waiting for warnings, especially during winter months. Not worth getting stuck somewhere. It’s going to fail at some point, they all do whether EV or ice. At the very least, monitor the voltage in service mode.

 

[Wattsisname]

Was this a Li-Ion 15 volt battery? I thought Tesla changed the LV battery to Li-Ion in 2020 or 2021. My 2022 Model X has a Li-Ion LV battery.

If this was the Li-Ion LV battery it is the first time I have heard of one of these failing.

Indeed!

Was this a Li-Ion 15 volt battery? I thought Tesla changed the LV battery to Li-Ion in 2020 or 2021. My 2022 Model X has a Li-Ion LV battery.

If this was the Li-Ion LV battery it is the first time I have heard of one of these failing.

In the UK, a 2022 would have the 15 volt Li-Ion. Can't speak for US made cars.
Perhaps the OP will " enlighten" us.

 

[jcanoe]

In the US, Model 3 and Model Y that have the AMD Ryzen processor also have the 15.5V lithium low voltage battery as opposed the earlier Intel Atom processor and the Hankook ATLASBX maintenance free flooded lead-acid 12V battery.

 

[CinCLT]

So is there an answer -- when should I consider changing my 16V battery? Will it go on forever?

 

[fiehlsport]

So is there an answer -- when should I consider changing my 16V battery? Will it go on forever?

Wait until the car tells you to. It has its own BMS and is constantly monitored. Early failures of these batteries are likely just due to defects, not indicating any sort of intended lifespan. I wouldn't doubt they can go 7-10 years, maybe more.