12v Battery - Normal Operating SOC?

[Regaj]

With Tesla now changing its 12v "starter" battery from lead acid to lithium-ion... I'm curious what state-of-charge the new lithium-based 12v batteries are operating at.

Lead acid batteries like to be kept fully charged, so the charging system in an ICE vehicle is usually pretty simple. As we all know, though, lithium-based batteries are much happier at a middling - say 50% - state-of-charge. Which is the whole reason Tesla recommends against routinely charging the HV battery to 100%.

Given all that, one would think that Tesla has implemented a charging scheme in the 12v battery that keeps its SOC somewhere around 50%. Has anyone here ever tested that? (My 2022 M3 is still about two weeks out, so I'm not able to check myself just yet).

Just curious...

 

[ATPMSD]

Lithium batteries are happiest when stored at 50%. The system monitors the voltage of the 12V battery and when it drops to a preset level (maybe 50%?) the battery is then recharged to 100%.

 

[Flybyglass]

Lithium batteries are happiest when stored at 50%. The system monitors the voltage of the 12V battery and when it drops to a preset level (maybe 50%?) the battery is then recharged to 100%.

I would also add the Tesla Lithium low volt battery is now around 15 volts (and is small).

 

[sightman]

I would recommend this and the corresponding YT videos. I watched the whole series and it was very interesting.

Tesla's New 12V Li-Ion Auxiliary Battery Has CATL Cells Inside

With the refreshed Model S/Model X, Tesla has switched from lead-acid to an all-new lithium-ion 12V auxiliary battery. Let's take a look.

insideevs.com