100% or 80%.... myth?? [preparing for a road trip]

[rengel79]

Hi guys, firstly apologies for this thread as I know there are some topics on this - but is there an issue with charging the car to 100% prior to going on a bit of a road trip?
I've owned my MYLR now for a whole 2 weeks, loving it.. factory setting was to charge up to 80% which seems to be working fine.. but given the long-ish drives ahead of us (Melbourne-Geelong return) + day trips in between I don't particularly want to be charging where we're staying and rely on the 1 charge to get us there and home over the upcoming long weekend. I've just been overwhelmed with so many youtube clips claiming 'for' and 'against' 100% charging... I just don't know where it stands anymore!

Tx...

 

[skriefal]

but is there an issue with charging the car to 100% prior to going on a bit of a road trip?

No. If there was an issue with this then the option to do so would be unavailable. But do avoid charging to 100% at all times, where the car might end up sitting at a 100% charge level for much of its life.

 

[jjrandorin]

. I've just been overwhelmed with so many youtube clips claiming 'for' and 'against' 100% charging... I just don't know where it stands anymore!

None of those youtube clips and the thousands and thousands and thousands (and thousands) of posts of discussion about charging, say anything about not charging to 100% if you are going on an actual road trip.

If you are going on a road trip and want to charge to 100%, do so. the car isnt going to explode.

=========================
(Moderator note)

Added "preparing for a road trip" to the thread title, because that was your specific question and in the first couple of sentences of your post.

There is a market difference is "can I charge to 100% all the time" and "can I charge to 100% while I am preparing for, or on a road trip?" and the second thing is the one you asked. If you want to discuss "all the time" there are several dozen threads I could point you to instead.

 

[rengel79]

None of those youtube clips and the thousands and thousands and thousands (and thousands) of posts of discussion about charging, say anything about not charging to 100% if you are going on an actual road trip.

If you are going on a road trip and want to charge to 100%, do so. the car isnt going to explode.

Thanks @jjrandorin and apologies again for the thread on this.. I know there are a bazzillion of these q's out there... good to get it validated!
I didn't think it was an issue as rightfully so - it wouldn't be an option if it presented itself as an issue.
I'll be going 100% charge the night before we head off for the trip... (first stretch of road will be approx 95km so the first X% will get gobbled up pretty quickly already!)

 

[jjrandorin]

If you want to alleviate a little bit of the concern people tend to have with "charging to 100%" the "best" thing to do is to have the car finish charging to 100% as close to when you are actually going to leave on the trip as possible.

So, if you are charging to 100% the night before, do just a bit of math and see how many hours its going to take for your car to charge to 100%. Leave a buffer of around 45 minutes (in case the car wants to balance its cells while sitting at 100% before finishing).

Then, set scheduled charging to start at a time that has the car finishing charging about 45 minutes before you are leaving.

None of that is necessary, of course, but if you have the leeway in charging time its a bit better to have the car hit 100% close to when you are going to leave.

 

[davewill]

Absolutely nothing wrong with it, at all. However, I will say that it is also not necessarily as useful as we tend to think. If you're going to have to stop to charge on your way to the destination, anyway, then that extra 10-20% at the beginning probably isn't going to make a significant difference in your overall travel time.

Of course, there are edge cases where that extra charge is the difference between having to stop or not, or having to make an extra stop, but those cases really don't come up very often.

I am reminded of a one overnight trip where a snafu caused us to fail to charge the night before and we had to set out on our trip with 40% charge. It was a bit of a bummer to have to hit the Supercharger so early in our trip, but in the end, it was no real problem.

Of course, Since I started out with a first gen LEAF and had to REALLY plan even mildly long trips, any trip in a Tesla seems like child's play.

 

[Calliope]

No problem - I do it before road trips all the time (but only for road trips). It cuts down on the time (and cost) I have to spend at the Supercharger along the way.

 

[EVer Hopeful]

Absolutely nothing wrong with it, at all. However, I will say that it is also not necessarily as useful as we tend to think

That's a valid point. If you want to do the whole trip on one charge, then maybe 100% at the start would be the way to go, but if you'll be stopping to charge on the way, then remember that you'll charge faster the lower the SoC is (think of loading the trunk with suitcases and how easy it is at the beginning, then how it gets progressively more difficult as the trunk fills)

I'd say, put your route into ABRP, then give yourself an extra 10% or even 20% just so you feel comfortable. Then once you've done a few trips you'll see that arriving at a SC with "only" 10% is really not that big a deal

 

[ucmndd]

but if you'll be stopping to charge on the way, then remember that you'll charge faster the lower the SoC is

This is true, but for a given trip assuming the charging stops are fixed, leaving with more energy will always be faster.

There’s no reason NOT to start out a long trip at 100%. It can only be a positive in terms of time and options.

 

[EVer Hopeful]

I'm not sure I understand: the only way it would be faster is if you left with enough to skip one of the planned stops

...or do you mean that if at your first stop you were supposed to charge to 60%, then that would be faster if you arrived with 40% rather than 10%? That certainly makes sense and I hadn't looked at it that way

 

[davewill]

The main reason it usually makes little difference is because at the first charging stop, it takes maybe 5 minutes less to reach the charge level you need to reach the next stop and then the rest of the trip goes exactly how it would have anyway.

While it's true that arriving with a lower charge means you can initially charge at a faster rate, it won't take less time to get to, say 80% from 20% instead of 40%.

The time it makes sense to arrange to arrive at a charging stop with less charge is when you can do it by driving to a stop that is farther away, or by leaving a charging stop sooner.

Purposely not charging to 100% at home can't ever speed things up.

 

[EVer Hopeful]

. . . unless (and yes I'm being pedantic here) it was time to go and you were only at 90%

but I take your point

and if I was doing any kind of a long trip I'd get it to 100% first if I could, just because . . . runway behind you and fuel on the ground etc

 

[sirwm]

Hi guys, firstly apologies for this thread as I know there are some topics on this - but is there an issue with charging the car to 100% prior to going on a bit of a road trip?
I've owned my MYLR now for a whole 2 weeks, loving it.. factory setting was to charge up to 80% which seems to be working fine.. but given the long-ish drives ahead of us (Melbourne-Geelong return) + day trips in between I don't particularly want to be charging where we're staying and rely on the 1 charge to get us there and home over the upcoming long weekend. I've just been overwhelmed with so many youtube clips claiming 'for' and 'against' 100% charging... I just don't know where it stands anymore!

Tx...

you will discover that there is no real reason to charge above 80% with a supercharger while traveling.

For my two round-trips NJ-FLA, charging from 5% to 80% took the same amount
of time as charging from 80% to 100%.
It simply is not worth my time waiting for the car to charge above 80% on a supercharger
unless I am eating a relaxing lunch/dinner.

 

[MichaelSte2022]

Thanks @jjrandorin and apologies again for the thread on this.. I know there are a bazzillion of these q's out there... good to get it validated!
I didn't think it was an issue as rightfully so - it wouldn't be an option if it presented itself as an issue.
I'll be going 100% charge the night before we head off for the trip... (first stretch of road will be approx 95km so the first X% will get gobbled up pretty quickly already!)

Do not apologize for seeking knowledge, ever! Brand new owner of a used Model S 2016 and this sexy beast was brought in to service a little lock compartment repair inside and with that service time I asked this exact question. Here comes the answer from the engineer on the spot, who's speciality is high capacity batteries for Tesla and other E-vehicles. So here come some facts: The high capacity battery "feels best/ most healthy" long term with a 20%-80% charge. Having under 20 and over 80 is not recommended, however OK from time to time. If taking a long drive not expecting to be able to reach a charging station, especially if you simply just don't feel like it, he says, 100% is what he does himself, but only, and this is very important, ONLY if you are going to drive right away. Do not for example charge up to 90% or more percentage in the evening before your trip and then drive out early morning as having a high load, meaning high charge over 80 percentile is bad for the battery health. Here is how he laid out the scenario: Let's say you want to drive over 200 miles tomorrow morning at 7.00am and your charge is at 50% today. Leave it at 20% - 50% order night, get up a little earlier and head to your closest super charger station at about 6:00am for that 100% charge. Then within 5-10 minutes after the charging is completed you want to drive long range. Do Not Wait an hour to drive. A big no.

If using non Superchargers at your location use trickle charge at home but set the schedule to 100% for 7.00am and drive at 7, not 8am!


Hope this helps guys, I love Tesla....

 

[ucmndd]

Hope this helps guys

It doesn’t. Nearly all of this is disproven hyperbole. Spending an hour at 90% or 100% will do NOTHING measurable in terms of “damage” to your battery.

 

[posity]

Here comes the answer from the engineer on the spot, who's speciality is high capacity batteries for Tesla and other E-vehicles

Whoever you spoke with here completely misrepresented their knowledge. You have been bamboozled. This subject has been discussed ad nauseum here and everything you said is just plain uninformed. As a new owner, you will soon discover there is lots of misinformation out there, but the simplest rule is 'just drive the car and fuggedaboutit'. Your whole scenario about never going above 80% has zero basis in fact.

 

[LostVector]

The main reason it usually makes little difference is because at the first charging stop, it takes maybe 5 minutes less to reach the charge level you need to reach the next stop and then the rest of the trip goes exactly how it would have anyway.

While it's true that arriving with a lower charge means you can initially charge at a faster rate, it won't take less time to get to, say 80% from 20% instead of 40%.

The time it makes sense to arrange to arrive at a charging stop with less charge is when you can do it by driving to a stop that is farther away, or by leaving a charging stop sooner.

Purposely not charging to 100% at home can't ever speed things up.

Agree with all of this … it just doesn’t matter if I can potentially save a few extra minutes at a supercharger. That isn’t how my rest stops work, especially with a family.

For those that need to thirst every last minute out of their stops like a race, then sure, knock yourself out.

 

[Unclepaul]

I always charge to 100% prior to a long trip. Gives me more options as when to do my first on the road Superchage.

 

[rengel79]

Thanks all for the feedback here, and just confirming doing a slow charge (e.g at 10amp overnight) with my standard Telsa wall charger is a more cost efficient way of charging (trickle charge) rather than 'blasting' 32amps into it? I've got a single phase, 32AMP circuit connected to my wall charger.

 

[posity]

You have it backwards. At 10 amps you can end up providing no increased battery charge since it could all be consumed heating the batteries. 10 amps is therefore potentially highly inefficient. So if you want to save money (and time), do the 32 amp charge since that will consume a lower percentage warming up the batteries and you are guaranteed to be adding charge to the batteries.

And 32 amps is far from 'blasting' when you consider that a 250kw supercharger is up around 600 amps. 32 amps IS effectively a trickle charge from the battery's perspective.

The Tesla recommended 14-50 receptacle and 32 amp charge rate is ideal for mobile charging. No need to think you need to dream up a better strategy than the engineers who design the car.