12v battery

[alyuan]

Given the multiple lockdowns, does the community charge their 12v battery while the car is sitting idle? I use a ctek for my ICE cars, wondering if this is applicable to M3? any specific procedure to follow?

 

[BCTS]

Given the multiple lockdowns, does the community charge their 12v battery while the car is sitting idle? I use a ctek for my ICE cars, wondering if this is applicable to M3? any specific procedure to follow?

The Main Battery keeps the 12V Battery charged through the DC-DC Charger built into the car. I believe this only stops occurring under a certain battery percentage (likely to be around 10-20% or so).

Keep the Car charged at a reasonable level and its not an issue at all.

 

[cafz]

Yes, at least with the Model 3 you just need to leave it plugged in - it'll keep the main battery topped up from the charger, and the 12V topped up from the main battery.

The Model S - at least older ones - didn't seem to work that way and it was possible for the 12V to go flat if left for a long period, even plugged in.

 

[BCTS]

Yes, at least with the Model 3 you just need to leave it plugged in - it'll keep the main battery topped up from the charger, and the 12V topped up from the main battery.

The Model S - at least older ones - didn't seem to work that way and it was possible for the 12V to go flat if left for a long period, even plugged in.

Originally I think that was the Cafz but they changed that In a Firmware update to keep the batteries topped up more in Model S now also...

 

[paulp]

Yes, at least with the Model 3 you just need to leave it plugged in - it'll keep the main battery topped up from the charger, and the 12V topped up from the main battery.

The Model S - at least older ones - didn't seem to work that way and it was possible for the 12V to go flat if left for a long period, even plugged in.

Thats how the original model S was supposed to work, but a combination of random dud 12v batteries and questionable software made it a bit hit and miss. I was one of the lucky ones that seemed to always have my 12v charging well, and yet when I replaced that early car with a new model S the battery had to be replaced the week I recieved it. No issues since though, and I do nothing other than plug it in.