To stay plugged-in or not

To stay plugged-in or not

On the weekends I try to limit the use of my baby as much as possible. That also means not leaving it plugged-in. Is this a good idea? I know that Elon says a plugged-in Tesla is a happy Tesla, but I figure battery life will be better the less I keep it plugged-in. Am I wrong?

Bighorn | 10 maggio 2019

Plugged in doesn’t mean it’s actively charging, so no stress on the battery.

Aerodyne | 10 maggio 2019

Interesting. The only issue I have currently, (And I was going to search this up before posting) is when I plug in I get a lot of cycling of the contactors in the charge port, like every 5 min.

I think if you are monitoring the car, and your vampire drain is minimal, say 1kw a day, leaving it unplugged is no big deal IMO.

Storing at 50-60 percent will most likely be more beneficial than most anything else you can do.

pjw315 | 10 maggio 2019

You are going to doubt the word of a genius? He is not going to tell you to leave it plugged if it is bad for the car.

SO | 11 maggio 2019

I leave mine plugged in for months on end in the winter set to 50%. The car takes care of itself. Just set the charge level to less than 90%.

You don’t want to have a situation come up where no one is able to plug in the car and it drops to zero.

barrykmd | 11 maggio 2019

Yes, you are wrong. Always plugged in.

NCC1701S | 11 maggio 2019

Be sure to unplug when a thunderstorm comes calling. No sense in risking damage to a $100k computer.

kerryglittle | 11 maggio 2019

Leave it on life support when not using it.

EVRider | 11 maggio 2019

I think people worry too much about this. Do whatever is convenient for you — either way the car will be fine. I haven’t kept any of our 3 Teslas plugged in when not using them, and they seemed perfectly happy to me. :-)

kerryglittle | 11 maggio 2019

You are probably right EVRider. When I go to Tesla SC there are maybe 80 Tesla's in the lot waiting to be sold. They aren't being plugged in while sitting there. Whether they power them all down I have no idea what they do while they sit for weeks or months on end.

murphyS90D | 11 maggio 2019

My car is only plugged in when I am charging it. If the car is not actively charging, being plugged in does absolutely nothing. The contactor in the EVSE is not closed so no power is connected to the car.

Charsiubao | 11 maggio 2019

I believe leaving the car plugged in DOES serve some meaningful purpose... I left the car plugged in at 50% level and went on a 3 week vacation last year, when I came home, the car showed 50% battery life, so my interpretation would be that, when the car is plugged in when not used, the charger would actually monitor the battery health or level, and start charging when the battery is below a certain miles loss threshold when not used.

Bighorn | 11 maggio 2019

It does maintain charge whenever it drops a certain threshold.

EVRider | 12 maggio 2019

Of course keeping the car plugged in maintains the set state of charge, but there’s no significant benefit to doing so if you don’t need to. It does no harm either. Whatever works for you.

Anthony J. Parisio | 12 maggio 2019

While what you are doing isn’t hurting the car, it’s completely unnecessary. Why add complication to your life for no reason? I only put about 5000 miles a year on my car. I have done this for four years. It’s always plugged in and set to 80%. This leaves nothing to chance. It’s always ready with more power than I need. The only downside to this is the 12V battery gets used way more than if it was driven often. However the main pack shows no loss of miles. All the best.

Bill_75D | 12 maggio 2019

Anthony, can you elaborate on your statement " The only downside to this is the 12V battery gets used way more than if it was driven often."

I'm not clear why plugging in saves the 12v battery.

jordanrichard | 12 maggio 2019

Plugging in every day, by habit, removes any chances of running into a situation where you need to go somewhere unexpectedly and there is not enough charge.
When I first got my car, I did an experiment of seeing how long I could go without charging. I went 4 days, but then it dawned me that if I had to go somewhere out of state, I would be stuck. Now I will grant you that this was 5 years ago when there were only 3 superchargers in all of New England, now there are 10 here in CT alone.
However I still plug in every day.

Anthony J. Parisio | 12 maggio 2019

Sure, when we drive the DC to DC converters take over and the 12V batter is bypassed leaving it unused. So it is preserved just like in a Fossil car. However while sitting the computers, etc. are powered by the 12V battery. This means it is deep discharged and recharged at least 4 times a day. This much greater use than in any other car. So the 12V battery’s life is cut short. It’s very common for a car that sits as much as my car to need a new 12V battery every year or two years.

DRFLGD | 12 maggio 2019

Thanks everyone.

Anthony J. Parisio | 12 maggio 2019

Just to be clear, the ware on the 12V battery happens whether plugged in or no. It is sitting undriven that causes the excessive ware.

Yodrak. | 12 maggio 2019

"I figure battery life will be better the less I keep it plugged-in."

Why do you figure that?

redacted | 12 maggio 2019

@Anthony you'd have to drive quite a bit to extend the battery life by much. 6 hours/day of driving would only seem to extend it by months.

bill | 12 maggio 2019

@AERODYNE " your vampire drain is minimal, say 1kw a day"

I think your estimate of drain is way to low. That would say a Model S 90 would last about 82 days if left with a full charge.

I just moved to Denver Colorado and I am living downtown with no option to charge where I park. I left my car from 10:42 pm on May 6th with 216 miles of rated range and when I returned on May 10th at 2:13 PM I had 170 miles left. So I lost 46 miles in 87.52 hours. I believe rated range is based on 290 WH/mile. so 46 miles would be 13.3 KW or 3.67 KW/Day. The weather in that time period was on the colder side say an average of 45 degrees.

So this would suggest the longest you could leave a S90D unplugged assuming you left it at 80% and did not let it drop below 20% would be: 13.4 days if the average temp was 45 degrees F

(82 *.8) - (82*.2) = 49.2 KW / 3.67 = 13.4 Days

barrykmd | 12 maggio 2019

bill - that seems way too high. Is pre-conditioning on? Can't believe cabin overheat protection would have any effect the way the weather was last week :-)

I lose 3-4 miles/day.

bill | 12 maggio 2019

I do not believe so. I will check next time I am in the car. I am also going in for service Tuesday so I will check with them.

BPSoCal | 12 maggio 2019

@barrykmd - is that range loss on sentry mode as well? I have noticed much higher drain on sentry than not.

p.c.mcavoy | 13 maggio 2019

@bill - A couple things can influence your range loss.

- Cabin overheat protection enabled, even if the temperature is moderate, prevents the car from going into a deep sleep, increasing battery drain. I tried turning it on one day, when cool, and saw drain much greater than normal.

- Similarly, keeping the app active on your phone, or some other 3rd party apps depending upon how set, will increase the drain in the car. Again, this is due to preventing the car from going into a deeper sleep state.

- Drop in battery temperature will result is what looks like vampire drain. This is actually what I think most likely in your situation. If you had been driving the car such that the battery was warm, and then it's fully cooled over 2-3 days to 45F range, then you'll have seen some range drop simply due to the fact that the battery is able to provide less available energy at a cooler temp. I've observed this on several occasions, and actually caught it a couple times via using a tool to remotely log my car. What I saw was I suddenly lost several miles (like 10) over the course of just a few minutes as the battery temp likely when across a break-point in the BMS estimation algorithm and my predicted rated miles dropped in a large step between to data points, ~ 30 minutes apart.

barrykmd | 13 maggio 2019

BPSoCal - I have an AP1 car and don't have sentry mode. however, running a camera should not be a high power consumer. I do have a Blackvue dashcam and it draws under 5W. Assuming it is 5W, 1 kWh is 200 hours, or 8+ days, of use.

sner66 | 13 maggio 2019

FWIW I have a 2014 P85 and plug in only when charge drops to less than 100 mi (usually keep battery in 40-70% range). Since I don't drive a lot, this means I charge about 1-2 times/week . I range charge before long trips and in 5 years my max has dropped only from 262 to 256.

I remember the "a plugged in tesla is a happy tesla" slogan but part of the impetus for that was to allay lingering range anxiety in the early days( I recall even Tesla technical battery people implying this). I doubt it makes a big difference if you plug in every night. There was a discussion on this topic over at the TMC forum.

Anthony J. Parisio | 13 maggio 2019

ABSOLUTELY not true!

bill | 13 maggio 2019

I do not have pre-conditioning on and I set the Climate Control to off when I leave the car. Here is an email I got from Tesla: (I let them know I have an S and not a 3).

Hi Bill,

I am the Virtual Diagnostic technician and I am looking into your concern for range loss. I have performed a remote battery check, and found that your battery is healthy! I also looked into the range loss on your vehicle, and have found that your Model 3 can consume up to 1.5% of energy a day while idle, this is mostly used on keeping the 12V battery charged, and connectivity to the Tesla Network. Checking on the car via the app will also use more energy, and not allow the car to “sleep”. Based on your concern that you lost just under 4 miles per day, I would suspect that is normal!

Please let me know if you have any additional questions or concerns.

Best regards,

bill | 13 maggio 2019

Is there a way to power down the car and leave it? When I power down the car and open the door it powers it back up. Also would that cause the 12 volt batter to drain? I would expect the drain on the 12 volt is caused by the car being powered up.

Aerodyne | 13 maggio 2019


Per Tesalfi, I do loose only about 1 to 1.3 Kwh a day.

I always keep in plugged in. Not just because some genius is addressing some edge cases like storage and the like, but less wear and tear on The MC and charge port, and as insurance should the 12V take a dump and leave the BMS inop. in hot weather.

Yodrak. | 13 maggio 2019

ABSOLUTELY not true!"

Yes, but does not answer the question I asked. What makes the OP think it would be true?

Bighorn | 13 maggio 2019

Not sure Anthony realized you were on the same page.

bill | 14 maggio 2019

Unfortunately my current parking situation does not allow me to charge, I am living in Denver Down Town and parking at the convention center. So I have to take the car to the nearest supercharger to keep the car changed. So I am focused on how long I can leave it before I need to bring it for a charge. There is a supercharger out by the airport which is not to far away so if I don't let it fall below 20% I should be ok.

I think I may know why my car is consuming so much. I checked all the settings and they are all set for minimum energy consumption. I have been using Teslalog since I bought the car so it appears that may be the culprit.

One thing that would help is if the car could message the phone app. That way it could send it the info, like amount of charge so that the phone would not have to wake up the car to let you know how much charge you have.

This way when the car is parked and not plugged in it could send the info to the app and go into deep sleep. It could wake up periodically to refresh the data which could be as little as once a day. Then when you use the car it could go back into the way it works now.

booshtukka | 14 maggio 2019

I always leave mine plugged in. Sometimes I'm away long enough that otherwise the battery could go flat, and it's been made clear that that is A Bad Thing.

If there was a way to properly shut it down and have no vampire drain, I could do that, but I didn't think that was an option?

bill | 14 maggio 2019

It is interesting that one of the main goals of the Tesla is to reduce energy waste and while some may think the loss is small but now that there are over a half a million Teslas out there and growing dramatically that small amount per car becomes is significant.

As for carbon emissions don't forget a significant amount of the electricity used to charge your Tesla is still coming from fossil fuels.

I would think it would be a priority for Tesla to figure out how to reduce the vampire drain as much as possible.

Even at 1 KW per day that is over 1/2 a megawatt loss not even considering the amount of energy lost charging that KW (line loss and inefficiencies of the charging).

murphyS90D | 15 maggio 2019

All of the electricity to charge my car comes from the solar panels on the roof of my house 50 weeks of the year.

Vampire drain can be totally stopped by disconnecting the 12 volt battery. Keeping it charged is the source of the vampire drain. Connecting a quality 12 volt battery charger to the 12 volt battery will also stop the loss of charge in the HVB.

Anthony J. Parisio | 15 maggio 2019

Bighorn you are right.
@Yodrak sorry I didn't understand you were agreeing.

barrykmd | 15 maggio 2019

bill - Are you not aware that there are 3 EV chargers in the Denver Convention Center parking garage? They are free to use. Check their web site, or plugshare, for details.

Aerodyne | 15 maggio 2019

For those that use logger software like Teslafi...

Turned off all sleep modes, and Vampire drain doubled.

Signed up for Clean Power, so all my power comes from renewables, I do not worry about the vampire drain.

Yodrak. | 15 maggio 2019

"sorry I didn't understand you were agreeing."

No problem. The OP still has not answered the question.

Yodrak. | 15 maggio 2019

"Signed up for Clean Power, so all my power comes from renewables,"

No, it does not. You are just paying as if it did.

Electricity flows according to the laws of physics, money flows according to contracts. They are two different paths and the latter does not change the former.

bill | 18 maggio 2019

"bill - Are you not aware that there are 3 EV chargers in the Denver Convention Center parking garage? They are free to use. Check their web site, or plugshare, for details."

I have only been able to find one on P1. It is to bad they do not have any 115 Volt plugs near spots that would be perfect,

My plan is if I get to low I can go in the evening when there is a good chance no one is using the one charger.

bill | 18 maggio 2019


I looked at plugshare and they say there are three charger less plugs near the entrance to P1. I will have to check that out.


Aerodyne | 18 maggio 2019

Yodrac...not all my electrons entering my meter come from non carbon generating sources, true. Only 50% on average in my area.

The other 50% is purchased on my behalf from said sources by clean power alliance, so says the contract.

I'm not convinced solar on my roof is the way to go with only 13KwHr usage per day. This is a reasonable, reversible, no risk alternative.

bill | 18 maggio 2019


Just came back from a visit to the Denver Convention Center Parking. There is only one charging station in the parking garage. The other three spots have no charging capability, they are only spots reserved for Hybrids and EVs. Interesting that two of the three were in use and were not either EV or Hybrids. Especially since there was plenty of parking and these are not even conveniently located.

When Plug share said no chargers were available I thought it meant there were Nema Plugs but it means no charging!

It wasn't a wasted trip since the Charge Point Charger was available and I was in need of some electrons.

barrykmd | 18 maggio 2019

bill - sorry about the confusion. Yhe one time I was there, I parked in the first EV spot I saw. At that time, the garage was pretty empty, as there was no event going on. I parked there to meet a friend for lunch a few blocks away.

This is from the convention center's web site.
Three FREE Parking Spaces for Hybrid and Electric Cars:
The Colorado Convention Center Parking Garage has designated three reserved parking stalls for Hybrid and Electric Vehicles for up to 8 hours of FREE parking. These free "Green" stalls are offered on a first come first serve basis and when available are located on level P1 in the garage. Thank you for partnering with the Colorado Convention Center to reduce our impact on the environment and our valuable natural resources.

An electric vehicle charger is also available in space 1081 for up to 8 hours of parking. Customers with a charge point card can utilize the charger (parking fee applies for this space).

Earl and Nagin ... | 19 maggio 2019

@bill and @barykmd,
Interesting to hear followup about the Colorado Convention Center. I mentioned the issue of the silly "green" car spaces (for stupid LEED compliance) to their management many years ago, suggesting the strong benefit that an EV charger would actually make. I'm glad to hear they have at least one charger although, clearly, they still, really don't get it.

the.hulk | 19 maggio 2019

The owner's manual explicitly states to plug in the car when not in use to maximize battery life and there's no benefit to waiting until there's a low SOC before charging.

Follow the manual would be my recommendation