Does disconnecting 12V prevent vampire drain?

[IdaX]

How long did you leave it parked? Did you leave sentry mode on?

Vampire drain should only be 4-5 miles a day unless you're constantly waking the car up or have sentry on.

This was in December, before Sentry Mode. Left it for Dec 20 to Jan 8 at the airport. Obv was super cold out; presumably some of the drain that I experienced must have been from battery conditioning in the cold weather?

 

[dennisvab]

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.

My model 3 sat an the auto auction for over 2 months with a dead 12 volt. I obviously don’t know how much charge there was initially but I picked it up with 174 miles of charge left. Also during my rebuild I left it outside in the freezing temps with the 12 volt taken out. There was almost no drain of the HV.

 

[rhaekar]

This was in December, before Sentry Mode. Left it for Dec 20 to Jan 8 at the airport. Obv was super cold out; presumably some of the drain that I experienced must have been from battery conditioning in the cold weather?

You're vampire drain is going to be huge if it's very cold outside. No wonder you drained your battery.

OP is in socal.

 

[ebmcs03]

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.

I left it parked for 2.5 weeks when i went to japan and lost a total of 30 miles. That’s about 10% of the battery.

 

[Tha_Reaper]

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.

I think you should use teslafi and find out if your car even goes into sleep mode at all, and use teslafi otherwise to force it into sleep mode. i only have the car for 1 week now, but the first 2 days the battery drained 3-4% overnight. Now i use teslafi with good sleep mode settings, and the drain is reduced to 0,2-0,3% overnight.

 

[IdaX]

I think you should use teslafi and find out if your car even goes into sleep mode at all, and use teslafi otherwise to force it into sleep mode. i only have the car for 1 week now, but the first 2 days the battery drained 3-4% overnight. Now i use teslafi with good sleep mode settings, and the drain is reduced to 0,2-0,3% overnight.

I didn't want to pay for TeslaFi... but I'll take you up on your suggestion and investigate the sleep issue with it. Will report.

 

[Tha_Reaper]

I didn't want to pay for TeslaFi... but I'll take you up on your suggestion and investigate the sleep issue with it. Will report.

You can try it out for 4 weeks for free if you use a referral code

 

[Garlan Garner]

The drain is not that bad.

I'm not sure what the complaint is.

 

[joelliot]

You're vampire drain is going to be huge if it's very cold outside. No wonder you drained your battery.

OP is in socal.

Pretty sure if you disconnect like this and freeze your battery, warranty will not cover the repair.

 

[IdaX]

Pretty sure if you disconnect like this and freeze your battery, warranty will not cover the repair.

Well, I mean, the battery freezes anyway once the battery's drained... I haven't seen any anomalous deterioration since the incident yet, tho!

 

[rrolsbe]

My model 3 sat an the auto auction for over 2 months with a dead 12 volt. I obviously don’t know how much charge there was initially but I picked it up with 174 miles of charge left. Also during my rebuild I left it outside in the freezing temps with the 12 volt taken out. There was almost no drain of the HV.

Something must of happened to the 12V battery quickly, shorted cell etc. My understanding is the car will wake up and top off the 12V battery from the traction battery until the traction battery reaches the 20% level which would be around 62 miles remaining for the Model 3 long range. They may of disconnected the 12V battery as recommended by Tesla if the car is going to be unplugged for more that three weeks. That said, I would not think the 12V AGM battery self discharge rate would not be that much in two months? You did not define freezing temps but the traction battery should have no problems setting at temps as low a -10F (maybe lower), if the charge level was not to low or high. When you picked up the car it was at about 60% SOC which should be close to optimal for long term storage.