One week in - first 100% charge?

[Dads-reward]

So, I'm just going to make most likely no more than 120-150 mile trip total (destination, maybe drive around then return). I was thinking of taking the charge to 100% right before I leave. That way I don't keep it at 100% for longer than 10 minutes, and get a lot of range and have plenty to spare for other potential adventures during the day.

Granted if I did, say 90% - usual for the last week for me based on Tesla recommendation (not getting into 90 vs. 80) -- 90% charge is about max 220 miles since I'm still accelerating hard and having fun. If I want to leave 20% in the tank (i.e., recommended to try to be between 20-90 for longevity reasons), that's about 50 miles. So, 150+50 = 200, giving me another 20 miles over and above leaving 50.

Thoughts? 100 (may help in keeping balanced), or since the car is new ... 90% is fine.

Thanks!

 

[TexasEV]

You’ve got this. Charge to 90% routinely and 100% for trips as you said. Just don’t leave it sitting a long time at 100%. The battery will be just fine.

 

[ewoodrick]

Feel free to go to 100% for trips. It will help you learn to get over the range anxiety.

At some point you'll realize that 70 miles left over range is more than a quarter tank and nothing to think about.

Stop listening to all of the numbers being thrown around. 20-90% has very little merit, and even if you accept the small truth in it, this is a trip and you get to remove most all of the rules. Even the on board nav will take you below 20%.

Do a little research, the highest mileage Teslas have over 400,000 miles and tend to Supercharger multiple times a day.

Tesla designed the battery so that you shouldn't worry about it, so don't, just enjoy the car.

 

[ewoodrick]

You’ve got this. Charge to 90% routinely and 100% for trips as you said. Just don’t leave it sitting a long time at 100%. The battery will be just fine.

Are you referring to the study that indicated that charging to 100% for a year loss a few percent of battery capacity?

 

[Dads-reward]

Cool. 100% for tomorrow trip it is!

 

[Salty Kitten]

I have a similar situation except my trip is 60 miles one way (car will sit for several hours) and then 70 miles. Would it be OK to charge to 100% before the first leg of the trip (i.e. Supercharge to 100% and embark on my 60 mile trip)

 

[darth_vad3r]

Supercharging all the way to 100% is slower, so if the SC is mid-way on your trip (and you have range anxiety) you can save yourself a bunch of charging time by visiting it twice for shorter visits when you have a lower SoC (state of charge on your battery).

But really, with a 130mi trip, 90% charge at home before leaving is fine. I only charge to 100% on trips that will end up taking >80% of my battery. As long as there's a charger around if you make unexpected detours you can always top-up.

Your trip is less than 60%, so if you start at 90% you can expect to make it back at 30% which is plenty margin to account for extra consumption from inefficient (fun) driving or a few detours. Supercharge at the end of your trip to get back up higher quickly if you want to test it out or if you have no other good charging setup to get back up to your normal daily use range.

My first trip was spur of the moment-ish and I left with only 65% on a trip that should take 100%-ish ... so I just had to SC twice, one on the way, once on the way back. All was good. Superchargers are great. If I had planned ahead I would have charged up to near 100% at home and then hit a SC on the way back for 5-10 minutes to make it back.

 

[eprosenx]

When going on trips (like to weekend destinations) I will take the car to 100% (normally I just charge to 80% daily because I really don’t need 90% daily).

If I am leaving in the morning and really want the 100% I will charge to 100% the night before. Otherwise I charge to 90% overnight and bump to 100% when I wake up. Sometimes I don’t make it to 100% when starting it in the AM but the two is fine for some of my destinations.

The reality is that I have never taken my car under probably 40% remaining, so charging to 100% is not necessary for these trips, but I like to have the “contingency” range. I often drive over the coast mountains to the beach and it is fairly frequent that there will be an injury accident or trees fall or a washout that closes the road forcing you to drive a very long way back (extremely limited mountain passes).

So basically, don’t worry about taking the car to 100% for short periods in order to take a trip. Just don’t do it every single day for no reason and leave it sitting there. Also, try to avoid 100% charging when it is super hot out, that is also not fantastic for the battery.

Do note that the last 15% charge slows down a ton. Going from 90 to 100 percent I think takes me 1:15 or 1:30 if I remember right even on my 48a 240v wall connector. The battery can’t take the juice that fast when you are cramming the last electrons in.

 

[EV-Tech Exp]

Great advice.

Also, charging to 97% vs 100% should help reduce degradation somewhat without meaningfully affecting the range available....

 

[darth_vad3r]

Great advice.

Also, charging to 97% vs 100% should help reduce degradation somewhat without meaningfully affecting the range available....

What if the car’s “100%” is really 97% already? Do we know that it isn’t? I think some manufacturers’ “100” isn’t a true 100, is it for Teslas?

If it is a true 100%, is driving down to 5% at the end of a trip instead of 8% better or worse than charging to 100% vs 97%?

What’s better?

1. Schedule a charge to 100% (to end shortly before trip begins), drive to destination arriving at 8%.
2. 97% -> 5%

I mean, the reality is that unless you are doing a one leg trip with no supercharging, going over 90% to 95, 97, 100% at the start of the trip is just saving you a few minutes at your first charge stop where you might arrive at 25% instead of 20%. It’s probably not even “a few” minutes. That’s probably literally 2 minutes or less to get from 20% to 25%, even at a 72kW urban supercharger*, never mind 120kW, upgraded 150kW, pre-conditioned battery en route, or heck, v3. Going from 90 to 100% will probably save you 60 seconds in the future for a 20->30% charge

Now if you think about it that way is saving some degradation worth 1-2 minutes extra at the beginning if your next supercharge stop? Probably.

Especially if you were waiting around at the start to get from 95% to 100%! If you were, you just traded away a whole bunch if time and battery stress for saving a couple minutes at your first stop.

So unless that first charge stop is well over 80% away, and you’re nervous about reaching it, I’d normally not bother going to 100%.


EDIT to add footnote:
*Ok, wow so I was almost right? 72kW at 100% efficiency would take 125s to give +5% to a 50kWh pack. Wow. I kinda thought I was borderline exaggerating, but not really.

 

[EV-Tech Exp]

What if the car’s “100%” is really 97% already? Do we know that it isn’t? I think some manufacturers’ “100” isn’t a true 100, is it for Teslas?

If it is a true 100%, is driving down to 5% at the end of a trip instead of 8% better or worse than charging to 100% vs 97%?

What’s better?

1. Schedule a charge to 100% (to end shortly before trip begins), drive to destination arriving at 8%.
2. 97% -> 5%

I mean, the reality is that unless you are doing a one leg trip with no supercharging, going over 90% to 95, 97, 100% at the start of the trip is just saving you a few minutes at your first charge stop where you might arrive at 25% instead of 20%. It’s probably not even “a few” minutes. That’s probably literally 2 minutes or less to get from 20% to 25%, even at a 72kW urban supercharger*, never mind 120kW, upgraded 150kW, pre-conditioned battery en route, or heck, v3. Going from 90 to 100% will probably save you 60 seconds in the future for a 20->30% charge

Now if you think about it that way is saving some degradation worth 1-2 minutes extra at the beginning if your next supercharge stop? Probably.

Especially if you were waiting around at the start to get from 95% to 100%! If you were, you just traded away a whole bunch if time and battery stress for saving a couple minutes at your first stop.

So unless that first charge stop is well over 80% away, and you’re nervous about reaching it, I’d normally not bother going to 100%.


EDIT to add footnote:
*Ok, wow so I was almost right? 72kW at 100% efficiency would take 125s to give +5% to a 50kWh pack. Wow. I kinda thought I was borderline exaggerating, but not really.

The vehicle indicated 100% is absolutely not 100% absolute SoC - probably somewhere between 97-98.5%, however a small step down from the max SoC which Tesla shows the customer to be 100% still does make a disproportionately beneficial difference to degradation. As you say, really, all this is doing is causing your charge stop to be very slightly longer. If you do intend to use the full range, then absolutely do charge to 100%.

On the topic of whether it is better to do 100-8% or 97-5%; the answer will differ for every cell, and will also be affected by temperature - if the battery is hot, 97-5% is likely better, however if it is cold, then 100-8% may be better. What is better for the Model 3? I don't know, but I'd be interested to hear about anybody that does this type of trip regularly.