Safe to charge SR+ to 100% and sit overnight before roadtrip?

[JWSM3Owner]

Hi all—I pick up my SR+ in a week and then I’ll be taking it on a 900 mi r/t road trip for the holidays. I usually don’t look forward to the drive but this year, there is no place I’d rather be than the driver’s seat of my new Model 3!

Question for the group: I know you aren’t supposed to routinely charge to 100% for battery health, except for road trips. My problem is that my condo doesn’t have charging yet, so I can’t use the scheduled departure feature. Do folks think it would be a problem to supercharge the night before to 100% and then let it sit overnight for about 10 hours? I figure the drive home + vampire drain would reduce it to 95% SOC by the time we leave bright and early the next morning.

Appreciate the feedback!

 

[davewill]

Sure. You only really need to think about this sort of this if you're doing it on a daily basis. For the occasional road trip, just do whatever you need to.

 

[ucmndd]

A couple ways to look at this.

First, the battery will be fine if you decide to do it this way. Some people will come in here and tell you you’re basically killing kittens by doing this, but that’s just hyperbole. Don’t make a habit of it or anything though.

Second, and perhaps more importantly, you should ask “do I need to?”

More specifically. Do you NEED the full 100% charge to make it to your first supercharging stop? If not, then there’s no reason to do this. In this case it won’t save you any time, it will actually cost you a bunch.

It takes a LONG TIME to supercharge to 100%, so you’ll be waiting around a lot the night before.

Let’s say hypothetically you charge to 100% and make it to your first charging stop with 30% left.

OR you charge to 90% and make it to your first charging stop with 20% left. The time it takes you to go from 20-30% at that first stop will be far far less than the time it takes you to go from 90-100% the night before.

So in short; I would only do this if you NEED the 100% to make it to the first charger. Otherwise you’re just wasting time.

 

[ItsNotAboutTheMoney]

Don't get your hopes up about picking up the car. Tesla has pulled the car from under plenty of peoples' feet

But it's not going to be hot then either, which makes sitting at a bit less than 100% less of an issue.

 

[toolman335]

Exactly, I was going to ask how far until your first Supercharging stop? Absolutely no reason to be at 100% unless that's how far you have to go on your first stop.
I do agree that it might be a bit premature to count on having that car and then immediately taking off for a long road trip. I hope you're staying at a friend's house and don't have hotel reservations lol.

 

[JWSM3Owner]

Thanks for the tip, I guess I figured I could rely reasonably well on my delivery appointment. Fortunately my trip’s a week later so if it slips a bit, no problem. If it slips a lot, well, that’s a different story lol.

The first supercharger stop I had planned to make is 145 miles away gaining elevation most of the way (I’ve got to cross the mountains to get from VA to OH). ABRP estimates I’d get there with 14% remaining if I started at 95% (want to see what Tesla Nav says). But there is a supercharger closer and you guys are right, starting lower/adding that stop doesn’t make a big difference time-wise, but does save the extra time/hassle the night before.

Planning an EV trip really is a paradigm shift. I instinctively want to start with a “full tank” but EV road trips seem to be a lot more about finding the right stops to minimize charge time.

 

[SigNC]

Which direction are you headed for the holidays? Lots of chargers on the east coast with the only real "stretch" being near savanna IMO.

 

[ItsNotAboutTheMoney]

Thanks for the tip, I guess I figured I could rely reasonably well on my delivery appointment. Fortunately my trip’s a week later so if it slips a bit, no problem. If it slips a lot, well, that’s a different story lol.

The first supercharger stop I had planned to make is 145 miles away gaining elevation most of the way (I’ve got to cross the mountains to get from VA to OH). ABRP estimates I’d get there with 14% remaining if I started at 95% (want to see what Tesla Nav says). But there is a supercharger closer and you guys are right, starting lower/adding that stop doesn’t make a big difference time-wise, but does save the extra time/hassle the night before.

Planning an EV trip really is a paradigm shift. I instinctively want to start with a “full tank” but EV road trips seem to be a lot more about finding the right stops to minimize charge time.

Warning: battery temperature.

I'm not sure where you're going, and at what ambient temperatures you have to start being concerned about battery temperature.

When the battery is cold, charging is slower. If you're driving in relative cold, it takes more time to warm up the battery.

An advantage of starting with a full battery is that you get more driving before you have to charge, which gives more time to for the battery to warm up, so you'll get a good charging rate even in colder temperatures.

Newer versions of the firmware software has a feature where if you set the navigation to a Supercharger it will use extra energy as you approach to warm up the battery.

I'm not sure what firmware version introduced battery warming. You should be good, but new cars don't all have the latest firmware.

Perhaps owners can chime in to give hard numbers of those two things: battery temperature, firmware battery warming on navigate.

 

[JWSM3Owner]

Which direction are you headed for the holidays? Lots of chargers on the east coast with the only real "stretch" being near savanna IMO.

Heading west from the DC area. Plenty of chargers along the way, thankfully, so no stretches where I'm worried about not making it. I'll probably be more conservative this first trip and give myself a greater buffer than others might, since I'll still be getting a feel for the new car, and really for EV's in general.

 

[SigNC]

Warning: battery temperature.

I'm not sure where you're going, and at what ambient temperatures you have to start being concerned about battery temperature.

When the battery is cold, charging is slower. If you're driving in relative cold, it takes more time to warm up the battery.

An advantage of starting with a full battery is that you get more driving before you have to charge, which gives more time to for the battery to warm up, so you'll get a good charging rate even in colder temperatures.

Newer versions of the firmware software has a feature where if you set the navigation to a Supercharger it will use extra energy as you approach to warm up the battery.

I'm not sure what firmware version introduced battery warming. You should be good, but new cars don't all have the latest firmware.

Perhaps owners can chime in to give hard numbers of those two things: battery temperature, firmware battery warming on navigate.

This is especially true in a RWD car. I've found it just can't put much heat into the battery when driving fast. The slower you drive the faster it heats the battery from what i can tell.

 

[ucmndd]

Heading west from the DC area. Plenty of chargers along the way, thankfully, so no stretches where I'm worried about not making it. I'll probably be more conservative this first trip and give myself a greater buffer than others might, since I'll still be getting a feel for the new car, and really for EV's in general.

Have fun and enjoy the trip! As you’re getting used to the car and EV travel in general taking your time and giving yourself plenty of buffer will go a long way toward reducing stress.

 

[JWSM3Owner]

This is especially true in a RWD car. I've found it just can't put much heat into the battery when driving fast. The slower you drive the faster it heats the battery from what i can tell.

That's interesting, any thoughts about why?

One thing about low temps, I park in an underground garage that seldom drops below 55 even on the coldest days, according to my current car. Not sure how that affects things--I presumed it would make it easier for the car to keep the battery warm, since the battery will already be reasonably warm. I figured there'd be a range hit regardless since it's typically 30-35 going through WV this time of year.

 

[ewoodrick]

Hi all—I pick up my SR+ in a week and then I’ll be taking it on a 900 mi r/t road trip for the holidays. I usually don’t look forward to the drive but this year, there is no place I’d rather be than the driver’s seat of my new Model 3!

Question for the group: I know you aren’t supposed to routinely charge to 100% for battery health, except for road trips. My problem is that my condo doesn’t have charging yet, so I can’t use the scheduled departure feature. Do folks think it would be a problem to supercharge the night before to 100% and then let it sit overnight for about 10 hours? I figure the drive home + vampire drain would reduce it to 95% SOC by the time we leave bright and early the next morning.

Appreciate the feedback!

Absolutely, positively okay to do.
The studies show degradation after many months of sitting at 100%

 

[hugh_jassol]

That's interesting, any thoughts about why?

One thing about low temps, I park in an underground garage that seldom drops below 55 even on the coldest days, according to my current car. Not sure how that affects things--I presumed it would make it easier for the car to keep the battery warm, since the battery will already be reasonably warm. I figured there'd be a range hit regardless since it's typically 30-35 going through WV this time of year.

Another thing about charging to 100% - for the first 30-40 miles of the trip you will not have the full regen braking available because a battery at 90+% charge cannot "accept" energy at the rate the regen produces it. So the car will limit regen until the battery is below about 85% or so. The same effect happens when your battery is "cold". In my experience, 55F is cold enough to cause the regen to be limited for a bit regardless of the state of charge of the batt. Once the batt warms up after 15-20 miles of driving, it's warm enough to get full regen again.

As for range loss in the cold...once the battery is warmed up, it almost doesn't matter what the outside temp is for efficiency. In fact if you had a garage that was 80F and then drive through 25 F (without using heat) for the whole battery, you will get very near full range. What kills the range most in the cold weather is starting out with a cold battery and cabin... then having to heat the batt and the cabin and not driving long enough to warm up the battery, parking for a while, then repeat. In that scenario, you will see significant range loss.

 

[JWSM3Owner]

Thanks, this is all super helpful. Appreciate the tips!

 

[OrthoSurg]

I usually charge to 90% de night before and when I wake up ai put the charge to full charge

By the time I eat breakfast, load the car, but my bike in the trunk it’s around 97% and then charging becomes extremely slow

So you don’t have the negative aspect of having the battery staying at 100% too often