Better to charge from 70% to 100% at 120V or supercharger before trip

[korkiley]

I'm taking a trip in three days and will have to leave my model 3 awd in a parking garage for a week or more.

I normally charge to 70% at home on 120V. Would it be better to slowly charge at home to 100% trying to time the charge so that it is complete just before leaving on the trip or would it be better to leave it at 70% then charge it to 100% at a supercharger a mile from my home? The Tesla app says it will take about 21 hours to charge from 70% to 100%. If 10 of those hours are spent charging between 90% and 100% isn't that equivalent or maybe worse than leaving the car charged at 100% for an equivalent length of time?

Thanks for your help!

Kor

 

[jjrandorin]

Do whichever is most convenient for you. You are talking about a single charge to 100%... its not going to matter, because you are not going to leave it at 100% for days. I suspect it would be easier for you to charge it at home to "whatever" before you leave, and then stop at superchargers as needed for your trip.

 

[gavine]

Supercharging from 70% to 100% would take a while too. Probably close to an hour. Supercharging past 80% is very slow.

 

[MrMassTransit]

Do you typically see much vampire drain? If I leave my Model 3 for a week unplugged, it drops from about 70% to 65% or so. I typically see less than a half mile of range drop per day. Unless your experience is different or you are doing a long drive before leaving the car, I personally wouldn't bother charging to anywhere near 100%. Just make sure that cabin overheat protection and sentry mode are off.

Also, hello from a former Burlington resident (I lived there for 8 years until I moved to DC in 2014). Nice to see some Tesla owners in the area. Also, I assume that the parking garage you'll be leaving it in is not the BTV garage. If it is, there are Tesla destination chargers there you can plug into free of charge (they're on the first floor). I suppose there is a chance they will all be occupied, but the handful of times I've been there in the last year I usually see 1-2 open.

 

[korkiley]

Thank you for your responses. My question was poorly phrased partly because I had originally meant to ask two questions, the one I actually asked and also concerns I have about leaving my car for about 10 days in a parking garage--how much charge can I expect to lose during that time. I need to have enough charge to comfortably reach the first supercharger on my return trip. That would probably be Tarrytown, NY.

Hello MrMassT. I've lived in South Burlington for close to 20 years but spent the most of my life in Charlotte. My trip is from South Burlington to New York City where I will be leaving the car in a parking garage. So I'm also worried about, yes, the vampire drain, which you have answered for me.

Since we bought our model 3 in June, it seems like there are suddenly Teslas everywhere in the Burlington area. There were already quite a few though. I don't know if Healthy living had the superchargers before you left. I think it was around 2014 that they were installed. Middlebury also has quite a few.

I know I am only talking about one trip but I would still like to know, in general, does charging to a high percentage on 120V equivalent to leaving the car at a high charge for a while before using it. My impression was that it is best to use the car immediately after charging to 90% and 100%. Maybe I'm thinking too much and maybe nobody can really answer that definitively.

 

[jjrandorin]

Thank you for your responses. My question was poorly phrased partly because I had originally meant to ask two questions, the one I actually asked and also concerns I have about leaving my car for about 10 days in a parking garage--how much charge can I expect to lose during that time. I need to have enough charge to comfortably reach the first supercharger on my return trip. That would probably be Tarrytown, NY.

Hello MrMassT. I've lived in South Burlington for close to 20 years but spent the most of my life in Charlotte. My trip is from South Burlington to New York City where I will be leaving the car in a parking garage. So I'm also worried about, yes, the vampire drain, which you have answered for me.

Since we bought our model 3 in June, it seems like there are suddenly Teslas everywhere in the Burlington area. There were already quite a few though. I don't know if Healthy living had the superchargers before you left. I think it was around 2014 that they were installed. Middlebury also has quite a few.

I know I am only talking about one trip but I would still like to know, in general, does charging to a high percentage on 120V equivalent to leaving the car at a high charge for a while before using it. My impression was that it is best to use the car immediately after charging to 90% and 100%. Maybe I'm thinking too much and maybe nobody can really answer that definitively.

What we know is that it is not great to leave the car at a maximum charge for a "long time". The charge between 90 and 100 is considered "high" state of charge by tesla I believe ( saying that because they denote 90 to 100 percent as "trip" in the charge meter. Charging to 100% at a supercharger will take you a long time because charging rate slows to protect the battery as you near max charge.

So, charging to that rate "slower" should not be a problem since that is what the car will do anyway at a supercharger.

As for your other question, parking without charging...

Make sure to NOT use sentry mode (as most people who park for an extended period of time would want to do). Make sure cabin overheat protection is OFF. Make sure to only check your car via the app infrequently (every check wakes up your car).

Doing that, you should lose somewhere between 1-5 miles per day. The average seems to be 2-3 miles a day. NOTE... if you use sentry mode, you will lose between 1 to 2 miles AN HOUR (so 24-48 miles per day). It is CRUCIAL you NOT use sentry mode when parking the car for an extended amount of time without being plugged in, unless you know that there is an ability to charge very close to where the car is parked.

So over 10 days, you would expect to lose between 10 miles to 50 miles or so, provided you dont use sentry mode or cabin overheat protection (I would turn off data sharing as well so that it doesnt try to download an update while you are gone, thereby waking up the car).

 

[korkiley]

Thank you for that. I had heard that sentry mode consumed considerable power but no idea it was that much! I won't turn it off or cabin overheat protection. Are there any other drawbacks to turning off data sharing? Will I still be able to use the app to check my charge level--OCCASIONALLY? : )

 

[Big Earl]

Why charge to 100% at all? You can make it to just about any Supercharger with a partial charge.

 

[jjrandorin]

Why charge to 100% at all? You can make it to just about any Supercharger with a partial charge.

Because OP is stating they will drive to their destination and then park for 10 days. Better to start off with as much range as possible when you do that, if you havent before, in the chance that you lose more range than you are expecting because of "something" (forgetting to turn off cabin overheat protection, etc).

Since we know that the car is designed to be charged up "as much as you need, when you need", what reason is there for this OP to NOT charge to 100 percent in this situation?

 

[korkiley]

Why charge to 100% at all? You can make it to just about any Supercharger with a partial charge.

Actually, I won't. I was looking at the worst case scenario and being new to traveling outside my area I'm a bit of a wimp. I've been looking at the route again with A Better Route Planner and it looks like I can safely leave with an 80% charge. There were other variations of my route that required a 90% charge though.

 

[justsomeguy]

Actually, I won't. I was looking at the worst case scenario and being new to traveling outside my area I'm a bit of a wimp. I've been looking at the route again with A Better Route Planner and it looks like I can safely leave with an 80% charge. There were other variations of my route that required a 90% charge though.

You can change a lot of settings in ABRP. You can tell it you don't want to charge to 100%, or not arrive with less than 20% and it will work some magic for you (where possible).

 

[Big Earl]

Actually, I won't. I was looking at the worst case scenario and being new to traveling outside my area I'm a bit of a wimp. I've been looking at the route again with A Better Route Planner and it looks like I can safely leave with an 80% charge. There were other variations of my route that required a 90% charge though.

ABRP is very helpful for planning. Have a great trip. Also, don't worry about charging to 100% if you need to.

 

[MrMassTransit]

To answer simply, there is no downside to charging to 100% on 120V. If you were planning to leave the car for weeks on end then it is not great for the battery, but for a handful of hours it is not a problem. Typically I charge to 95% prior to a road trip. I have 240V charging, but only charge at 24 amps given panel constraints. Leaving the car at 100% for anything less than a day is nothing to worry about.

For your scenario, if you are really worried, just charge on 120V to 97% or so. But you should have absolutely no qualms about letting the car sit above 90% for less than a day. Just charge on your 120V connection and don't worry about it.

On any road trip, if you find you are projected to not have enough range to make it to the next charging stop, just slow down by 5 or 10 MPH and you'll gain a decent amount of additional range via higher efficiency. I find I almost always beat the in car estimates by a good margin.

Since we bought our model 3 in June, it seems like there are suddenly Teslas everywhere in the Burlington area. There were already quite a few though. I don't know if Healthy living had the superchargers before you left. I think it was around 2014 that they were installed. Middlebury also has quite a few.

I think Health Living installed the Supercharger just after I left, but I've definitely seen it in my occasional trips up there. When I bought my Model 3, I listed my Leaf for sale online. The buyer ended up living in the Middlebury area, so I drove the car up to him and hit a few ChaDeMos on 7. I have some friends in Fairfax who are thinking about a Model Y when it comes out - so they're definitely becoming more popular.

 

[korkiley]

I’ve been parked in the parking garage for a week now. I’ve only lost roughly 2% or 6 miles. I took jjrandorin’s advice and turned off cabin overheat protection, avoided sentry mode and avoided checking on the car through the app. In spite of that, I have been in and out of the car numerous times to fetch things. I charged up to about 90% at Tarrytown which left me with about 84% by the time I parked here in Manhattan.

There were a couple of crazy coincidences. After I parked I asked the parking attendant if there were any charging stations in the garage. He pointed in the row directly across from me where I saw two chargepoint chargers and there was a white model 3, just like mine, charging at one of them.

The second coincidence was that in front of the building there was a black model 3 with Vermont plates. She was parked there for several days. I did, one day, see the owner sitting in her car. I would liked to have tapped on the window and talked to her but I didn’t want to scare her!

It turns out, we’ll be here until the 25th or 26th so I will observe my vampire drain carefully and report back. I switched to miles instead of percentage so I would have a more accurate reading of the projected mileage remaining. It was on 251 miles today.

I wished I hadn’t charged nearly as high in Tarrytown, no higher than 85% instead of 90%.

 

[darth_vad3r]

I’ve been parked in the parking garage for a week now. I’ve only lost roughly 2% or 6 miles. I took jjrandorin’s advice and turned off cabin overheat protection, avoided sentry mode and avoided checking on the car through the app. In spite of that, I have been in and out of the car numerous times to fetch things. I charged up to about 90% at Tarrytown which left me with about 84% by the time I parked here in Manhattan.

There were a couple of crazy coincidences. After I parked I asked the parking attendant if there were any charging stations in the garage. He pointed in the row directly across from me where I saw two chargepoint chargers and there was a white model 3, just like mine, charging at one of them.

The second coincidence was that in front of the building there was a black model 3 with Vermont plates. She was parked there for several days. I did, one day, see the owner sitting in her car. I would liked to have tapped on the window and talked to her but I didn’t want to scare her!

It turns out, we’ll be here until the 25th or 26th so I will observe my vampire drain carefully and report back. I switched to miles instead of percentage so I would have a more accurate reading of the projected mileage remaining. It was on 251 miles today.

I wished I hadn’t charged nearly as high in Tarrytown, no higher than 85% instead of 90%.

Curious what charge you decided to leave home at.

If I can comfortably make the first supercharger with 90% or less, I don't charge above 90%. Starting at 100% vs 90% only saves you 3-4 minutes at the first Supercharger. LOL.

e.g. You want to leave the first Supercharger at 85% and it takes you 60% to reach it.
a) Charge to 100% at home, drive 100% -> 40%, charge 40% -> 85%
b) Charge to 90% at home, drive 90% -> 30%, charge to 40% in 4 minutes, then ... continue charging as in (a)

This is exacerbated if this isn't your home->SC leg, but a SC->SC leg. If you wait for 90->100% it takes FOR EVER and all you are doing is saving literally a couple minutes at the next stop.

 

[jerseygirl18]

Do you typically see much vampire drain? If I leave my Model 3 for a week unplugged, it drops from about 70% to 65% or so. I typically see less than a half mile of range drop per day. Unless your experience is different or you are doing a long drive before leaving the car, I personally wouldn't bother charging to anywhere near 100%. Just make sure that cabin overheat protection and sentry mode are off.

Also, hello from a former Burlington resident (I lived there for 8 years until I moved to DC in 2014). Nice to see some Tesla owners in the area. Also, I assume that the parking garage you'll be leaving it in is not the BTV garage. If it is, there are Tesla destination chargers there you can plug into free of charge (they're on the first floor). I suppose there is a chance they will all be occupied, but the handful of times I've been there in the last year I usually see 1-2 open.

i'm curious..also a newbie. every day my schedule changes & there is nothing consistent about my travel distances
sometimes several short trips around my little town or once a week a trip to city 30 mi away. Should i have a regular pattern of charging or charge the nite before based on my plans for the next day? i have been ..chg nightly & go for 80% (have had car 6 days)
thanks in advance

 

[darth_vad3r]

i'm curious..also a newbie. every day my schedule changes & there is nothing consistent about my travel distances
sometimes several short trips around my little town or once a week a trip to city 30 mi away. Should i have a regular pattern of charging or charge the nite before based on my plans for the next day? i have been ..chg nightly & go for 80% (have had car 6 days)
thanks in advance

Keep doing what you are doing. It's nice to leave home with a full tank every day. For whatever "full" is for your typical needs.

If you are trying to ultra-optimize the health of your battery long term (like hundreds of thousands of miles) and you can easily get by with 70% daily, that seems to be the expert's opinion on the best (Prof. Dahn). Elon agrees, but thinks 70% is only marginally better than 80%. 90% isn't 'bad', but 80% is 'better'.

90% is better for the 'miles' calibration on your gauge. If it starts to bother you that that number drifts around, and down a bit, then you can change your charging habits to 90%, but even so, if you go 90-85-90-85-90-85 you'll still see the same "issues" (not a real issue unless you let the drift bother you). If it starts to REALLY tank a lot you can start being concerned it's not just a calibration issue but some actual battery issue.

 

[davewill]

...
I wished I hadn’t charged nearly as high in Tarrytown, no higher than 85% instead of 90%.

Don't sweat it. All of these "best practices" are much more important when thinking about daily behaviors. One incident of 10 days at 85-90% instead of 75% isn't going to mean anything significant.

 

[korkiley]

Curious what charge you decided to leave home at.

If I can comfortably make the first supercharger with 90% or less, I don't charge above 90%. Starting at 100% vs 90% only saves you 3-4 minutes at the first Supercharger. LOL.

e.g. You want to leave the first Supercharger at 85% and it takes you 60% to reach it.
a) Charge to 100% at home, drive 100% -> 40%, charge 40% -> 85%
b) Charge to 90% at home, drive 90% -> 30%, charge to 40% in 4 minutes, then ... continue charging as in (a)

This is exacerbated if this isn't your home->SC leg, but a SC->SC leg. If you wait for 90->100% it takes FOR EVER and all you are doing is saving literally a couple minutes at the next stop.

I forget how much I charged to at the supercharger near home. It was probably near 90%. I needed (wanted : ) to stop at two super chargers on the way to NYC. We stopped for the night at Lenox, MA but had to go 40 miles back to Williamstown the next day so first we drove 8 miles south to the Lee, MA supercharger where I charged from about 32% to 83%. The final supercharger before NYC was Tarrytown where I charged from 32% to 90%. I could have done 86% or less but until I have more experience I’m erring on the side of being extremely conservative. I arrived at the parking garage at Columbia University with about 83% charge.

A couple of days after my arrival here I sent an email to the Columbia University parking services asking if I could charge at the charger in the parking garage with my visitor permit ($22/day). I finally heard back from them today and they said I could! Of course it’s too late now but if I had known about that ahead of time I could have charged to a much lower level at Tarrytown.

I also stopped by the Tesla store on West 14th street here in Manhattan last Sunday. They confirmed my suspicion that the super chargers here in Manhattan are not practical. You have to pay for parking first of all, and then you would be lucky if you could find the space in front of the charger to be free once you’ve made that commitment. By the way, when my wife and I were walking on the street over that way today we saw a Mercedes plug-in hybrid charging at the curb from a cable that traversed the sidewalk covered by a protector (to protect pedestrians more than the cable I assume). It just goes to show you that where there’s a will there’s a way.

 

[korkiley]

Don't sweat it. All of these "best practices" are much more important when thinking about daily behaviors. One incident of 10 days at 85-90% instead of 75% isn't going to mean anything significant.

Yes, but if you discover that wasn’t true after all in five years, it will be too late! My impression is that no one really knows for sure about these things. Although I am somewhat reassured by statements such as yours, the skeptic in me find’s it difficult to accept without reservation!