Best practices for leaving M3LR while away

[Alset_Boston]

I am leaving for a 4 day trip and wanted some feedback on leaving the car plugged in or not? It would be charged to 80% and I would leave the AC off.
I’ve heard mixed reviews. Let me know your thoughts.

 

[GtiMart]

I don't understand the mixed reviews. Tesla recommends plugged, and that cannot hurt. If you can plug, plug. Then you can choose whether you want sentry or not, what SOC target you want etc.
Unplugged, your SOC will go down. For 4 days it's really not dramatic as there's no way you'll go from 80 to zero.

There's argumentation as to the target SOC or whether it's essential to plug or not. There's no argumentation about whether being plugged is bad or not.

 

[thefrog1394]

For 4 days, as long as you don't leave it under 10%, it really doesn't matter. As long as you don't have anything keeping the car awake (sentry mode, third party apps or a bad 12V battery), phantom drain is minimal. I parked my car on the street in front of my house at 15% on Tuesday and it's still at 15% as of this morning.

 

[Alset_Boston]

I don't understand the mixed reviews. Tesla recommends plugged, and that cannot hurt. If you can plug, plug. Then you can choose whether you want sentry or not, what SOC target you want etc.
Unplugged, your SOC will go down. For 4 days it's really not dramatic as there's no way you'll go from 80 to zero.

There's argumentation as to the target SOC or whether it's essential to plug or not. There's no argumentation about whether being plugged is bad or not.

Thanks. Appreciate the response. Seems that many have there own version of a best practice.

 

[GtiMart]

If you really want to learn about the best conditions for the longevity of your battery, there are hundreds of pages of threads around here. Makes for great bedtime reading If you want to keep it simple, you can, without completely destroying your battery. Being plugged ensures your SOC will never drop below a minimal acceptable level whatever happens, and does not have additional bad side effects. If you are not in a position to leave it plugged then you need to understand what makes the SOC drop and control it, leave enough SOC upfront etc... It's more complicated that's all.

 

[LoudMusic]

A.B.C.

Always Be Charging

I used to manually manage charging the car in the garage. That's a waste of my time. Plug it in and walk away. The car does everything else. If the battery does not need charge, it won't draw power. If the battery needs charge, it will draw power.

Other than running up the electrical bill there's nothing wrong with leaving sentry and cabin overheat protection on either. If it has mains power you might as well let the car protect itself.

 

[3sr+buyer]

For long term storage, you do not want to:

• Leave it at a high state of charge (>55% for NCA batteries, >70% for LFP batteries) that can increase battery capacity degradation. In general, degradation during storage is lower at lower state of charge all the way down to 0-1%, but (in lab testing of batteries) tends to get significantly worse above 55%/70% (though degradation is smaller/slower generally with LFP batteries than with NCA batteries).
• Allow it to fall to 0% or lower through vampire drain (which is much greater with sentry mode and/or cabin overheat protection with AC, but can still be a percent every few days with that stuff off).

So an easy safe way to park the car is plugged in with the target charge of 50% (the lowest allowed in the UI) (you can leave sentry mode and/or cabin overheat protection on, at the increased cost of your house electricity bill to keep it charged to 50%). If not plugged in, leave enough charge in it so that vampire drain will not pull it down to 0% or lower (but that requires knowing how much vampire drain there is through previous observation).

However, four days is not that long a time, so you have plenty of leeway with respect to vampire drain.

 

[Alset_Boston]

For 4 days, as long as you don't leave it under 10%, it really doesn't matter. As long as you don't have anything keeping the car awake (sentry mode, third party apps or a bad 12V battery), phantom drain is minimal. I parked my car on the street in front of my house at 15% on Tuesday and it's still at 15% as of this morning.

Makes sense and it’s at home so the sentry would be off. Appreciate the response.

If you really want to learn about the best conditions for the longevity of your battery, there are hundreds of pages of threads around here. Makes for great bedtime reading If you want to keep it simple, you can, without completely destroying your battery. Being plugged ensures your SOC will never drop below a minimal acceptable level whatever happens, and does not have additional bad side effects. If you are not in a position to leave it plugged then you need to understand what makes the SOC drop and control it, leave enough SOC upfront etc... It's more complicated that's all.

figured I would save some time and ask. It turns into a rabbit hole!

A.B.C.

Always Be Charging

I used to manually manage charging the car in the garage. That's a waste of my time. Plug it in and walk away. The car does everything else. If the battery does not need charge, it won't draw power. If the battery needs charge, it will draw power.

Other than running up the electrical bill there's nothing wrong with leaving sentry and cabin overheat protection on either. If it has mains power you might as well let the car protect itself.

well said! Like the ABC…

 

[SR123]

Yeah but you're gonna have a higher electric bill

 

[RayK]

Give me your key(card) and I'll take care of it for you while you're gone .

A couple of years ago I left on a trip to Portland, ME (October 2019). We were out there for 8 days. I left my car in the driveway unplugged; didn't really have a choice since I didn't (and still don't) have a home charging setup. Left it at 277 miles (90%). The car lost 13 miles (no cabin overheat protection and no Sentry mode). It also updated the software twice during that time. I remotely checked on it a couple of times. In short, I don't think you need to worry about leaving the car at 80% for less than a week unplugged, or plugged for that matter. The battery will be fine and you're not going to harm it in any way.

 

[Alset_Boston]

For long term storage, you do not want to:

• Leave it at a high state of charge (>55% for NCA batteries, >70% for LFP batteries) that can increase battery capacity degradation. In general, degradation during storage is lower at lower state of charge all the way down to 0-1%, but (in lab testing of batteries) tends to get significantly worse above 55%/70% (though degradation is smaller/slower generally with LFP batteries than with NCA batteries).
• Allow it to fall to 0% or lower through vampire drain (which is much greater with sentry mode and/or cabin overheat protection with AC, but can still be a percent every few days with that stuff off).

So an easy safe way to park the car is plugged in with the target charge of 50% (the lowest allowed in the UI) (you can leave sentry mode and/or cabin overheat protection on, at the increased cost of your house electricity bill to keep it charged to 50%). If not plugged in, leave enough charge in it so that vampire drain will not pull it down to 0% or lower (but that requires knowing how much vampire drain there is through previous observation).

However, four days is not that long a time, so you have plenty of leeway with respect to vampire drain.

Nice. Good insight.

Give me your key(card) and I'll take care of it for you while you're gone .

A couple of years ago I left on a trip to Portland, ME (October 2019). We were out there for 8 days. I left my car in the driveway unplugged; didn't really have a choice since I didn't (and still don't) have a home charging setup. Left it at 277 miles (90%). The car lost 13 miles (no cabin overheat protection and no Sentry mode). It also updated the software twice during that time. I remotely checked on it a couple of times. In short, I don't think you need to worry about leaving the car at 80% for less than a week unplugged, or plugged for that matter. The battery will be fine and you're not going to harm it in any way.

thanks for the insight!

 

[SR123]

ok so serious answer, a Tesla drains about 0.47% of battery a day(assuming sentry mode isn’t on because it drains a lot of battery). So as long as you leave your Tesla on a charge level that sounds reasonable to you, it should be fine. No need for charging for four days straight

 

[father_of_6]

Other than running up the electrical bill there's nothing wrong with leaving sentry and cabin overheat protection on either.

From my understanding, sentry and overheat protection won't run off A/C, so this will drain the battery. Being plugged in will keep it charged, but this will still add "cycles" to your battery, and you only get so many.

Granted, it's probably negligible for a one week trip.

 

[3sr+buyer]

ok so serious answer, a Tesla drains about 0.47% of battery a day(assuming sentry mode isn’t on because it drains a lot of battery). So as long as you leave your Tesla on a charge level that sounds reasonable to you, it should be fine. No need for charging for four days straight

At that rate of vampire drain, you need at least 2% if left unplugged for four days.

 

[SR123]

Yeah