-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
Does disconnecting 12V prevent vampire drain?
- Thread starter SoCalGuy
- Start date
smatthew
Active Member
Tam
Well-Known Member
Wouldn’t matter. Disconnecting either terminal prevents current flow, isolating the battery. But, the car seems to realize the 12V battery is “gone” and compensates.
And since the computer sees the battery as discharged, it would turn the charging circuits on. This will then have a tendency to run the main battery down.
I believe the right answer it\s to disable remote access and I believe there might be an option to shut the car down.
Lasttoy
Active Member
Tam
Well-Known Member
Owners can't turn off your Tesla completely with the suggested procedure of remote access off and on-screen power off.
The BMS still monitors its main battery status and automatically thermoregulates its optimal temperature in its deep sleep.
I assume communication to its mothership won't stop completely in case Tesla needs to push some urgent mandatory safety updates...
Tam
Well-Known Member
Disconnecting the 12V sounds great in theory but we won't know for sure until someone can report that they actually did it with good results after coming back from a vacation.
IdaX
Member
I've got a 2.5-week trip planned coming up, so if anyone has success, I'm interested in hearing about it!
IdaX
Member
Last time I did that I came back and the car was dead -4%. Had to jump it from an ICE and run a 120V cable into the terminal while illegally parked for 4 hours, then charged overnight at a hotel before driving home 40 miles. Not a great experience.
So "charge it to 80% and forget about it" is a dumbassed idea. I need a real solution.
vjason
Member
This is an example of a scenario that needs a known good “fix” if we want any EV to gain mass market adoption (let alone Tesla).
I’ve been out of country since Friday mid- day and while my car is at home plugged in I lowered the charge threshold so I could monitor the drain. So far I’m getting the usual 2-3 miles per day, but I knew to expect this.
The car needs a sort of non-home “park” charge indicator like with long distance trips. As in I’m driving 75 miles to the airport and will be gone 2 weeks am I ok as is or should I top off.
An EV needs to be as effortless to park and leave as an ICE. It’s pretty easy to do, but the vampire drain question comes up far too often (and let’s not get started on using heaters).
I’ve been out of country since Friday mid- day and while my car is at home plugged in I lowered the charge threshold so I could monitor the drain. So far I’m getting the usual 2-3 miles per day, but I knew to expect this.
The car needs a sort of non-home “park” charge indicator like with long distance trips. As in I’m driving 75 miles to the airport and will be gone 2 weeks am I ok as is or should I top off.
An EV needs to be as effortless to park and leave as an ICE. It’s pretty easy to do, but the vampire drain question comes up far too often (and let’s not get started on using heaters).
jdcollins5
Member
When a Mobile Tech changed out a Card Reader on a friend’s car, he opened the disconnect under the right, rear seat and then disconnected the 12V battery to isolate the 12V electronics. From what my friend understood, the disconnect isolated the HV battery and DC-DC 12V converter and then isolating the 12V battery isolated all power to the 12V electronics.
Similar threads
