What happens to my Tesla 3 if I leave it in the garage unplugged for 7 months?

[.jg.]

Seriously? I am not saying your wrong, but I would love to see more discussion of this option. I guess you are talking about shutting down the BMS and all systems for 7 months? I am not sure that is a good idea. I think the BMS runs everyday for a reason (looking for bad cells, balancing, ? ...). Multi-cell batteries like Tesla uses may require monitoring and correction. I am not really sure. I would be interested in what other people think about the adviseablity of this option?

Tesla say the car should be plugged in, specially if planning to leave it parked up for a while - for the reasons you state. Tesla also suggest that one should not leave the car charged to 100%, so a limit between 50% - 80% seems appropriate. I can't see any reason to do otherwise.

There does seem to be a question mark about how the 12V battery is treated when a Tesla is parked for while and attaching a battery tender would not do any harm.

 

[eladts]

Hello all,

I am planning to take an extended trip abroad. What is the best way to leave my Tesla 3 in the garage during 7+ months? Should I leave it plugged to the wall charger? Unplugged? Has anybody done this? Your advice is welcome. Thanks!

Sell the car and buy another one when you are back. Don't let the car go to waste doing nothing.

 

[jerry33]

Yes - plus the car seems to do stupid stuff to the 12v battery. Some guy did some measurements and analysis, which showed that the car was putting the 12V battery through 5 charging sessions per day. https://syonyk.blogspot.com/2016/10/tesla-model-s-12v-battery-analysis.html This might explain the relatively short lives of 12V batteries in Tesla cars.

That may have been true early on, but the last 12V battery was installed in my 85S five years ago. It's probably time for a new one (no alert yet), but five years is pretty normal for any 12V battery, so the current battery doesn't owe me anything.

And Yes, I'd leave the car plugged in for long term storage. I could be plugged into a 120V outlet. Set the battery level at 50%.

 

[AlanSubie4Life]

I think the BMS runs everyday for a reason (looking for bad cells, balancing, ? ...). Multi-cell batteries like Tesla uses may require monitoring and correction. I am not really sure

I don’t think we know this. I think it is unlikely that balancing takes place when the car is not plugged in. Tesla doesn’t give us info about when the BMS runs, and BMS is probably not the source of daily drain, as most of that drain probably occurs when the HV battery is disconnected (we would need 12V battery data to confirm that assertion though).

 

[rrolsbe]

You don’t want this. Shorter charging cycles are better. I know Elon once said that “70 to 30” is best but that was for someone that literally drove 40% of their battery daily. I asked a few battery experts and the answer is the same, keep it to short top-ups.

I agree shorter charging cycles are better but NO charging cycles are even better. I tired to use a NOCO G7200 Smart Charger on my Model 3 as a battery tender without any success. A few Tesla Model S owners have had good results using the same charger as a battery tender (ie.. car parked for months without any loss of traction battery charge level and NO charging was required).

 

[ReddyLeaf]

Mousetraps, flat spots on tires, to plug or not, what charge level to maintain..... these are all important items that can be solved by one simple solution: You need a house sitter. When should I arrive?