12 volt battery(ies) management

[Aka-none]

So the car has 1-2 12v batteries but how are they maintained and how can we see their status before they die and leave me stranded?

 

[bcjenkins]

So the car has 1-2 12v batteries but how are they maintained and how can we see their status before they die and leave me stranded?

My LEAF is the same. I know the 12V is dead when I receive a fault and cannot start the car.

A third party BMS is probably the only way to manage this.

 

[EVCar]

So the car has 1-2 12v batteries but how are they maintained and how can we see their status before they die and leave me stranded?

This was a very active discussion back in 2022, here as well as other EV fora. Seems like not a frequent event as previously feared. There was even talk about a gadget that would allow you to read the current voltage. The access is also not very user friendly.

 

[Aka-none]

I wonder if any of those odd items in the api are related to the 12 volt battery

 

[californiaboy935]

Interesting

 

[ke2]

Are peoples 12V batteries dying that frequently? From what I've seen on ICE cars if the 12V battery isn't in the engine compartment getting heated and cooled all the time and having engine/road debrie splattered on the battery the 12V batteries last years. In my BMW Z3 I don't ever recall replacing the battery (12V battery was in the trunk) and my Prius the batter is likewise not in the engine compartment and lasted 12 years. My honda civic hatchback on the other hand had all kinds of battery life problems (battery was in the engine compartment near the radiator). On a lucid I'd expect the 12V battery to be in a nice secure place without large temperature gradients or any debrie getting to the battery. So I'd expect the battery life to be a decade or more.

 

[Aka-none]

Are peoples 12V batteries dying that frequently? From what I've seen on ICE cars if the 12V battery isn't in the engine compartment getting heated and cooled all the time and having engine/road debrie splattered on the battery the 12V batteries last years. In my BMW Z3 I don't ever recall replacing the battery (12V battery was in the trunk) and my Prius the batter is likewise not in the engine compartment and lasted 12 years. My honda civic hatchback on the other hand had all kinds of battery life problems (battery was in the engine compartment near the radiator). On a lucid I'd expect the 12V battery to be in a nice secure place without large temperature gradients or any debrie getting to the battery. So I'd expect the battery life to be a decade or more.

This is a case where there isn’t a direct comparison. In an ICE vehicle the battery has one job, start the engine. Even if it has voltage you can often tell it’s going bad as it begins having trouble starting the engine.


I haven’t seen anything similar in our vehicles, or anyone else’s either.

 

[borski]

Are peoples 12V batteries dying that frequently?

No, except for some models in the past. Ioniq 5 had a problem with dying 12v (they’ve since fixed this I’m told) and Lucid Air had a problem where the HV battery would need replacement but the symptom was the 12v died. Long time ago.

For anyone wondering, there are two 12v batteries in your car, and they aren’t redundant.