Does anyone actually charge to only 80%?

[kort]

Why do they speak about 80% in the handbook ?

the 2020 version used 85%, newer versions say 80%

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[kort]

I own a Tesla as well. The section of the manual you showed doesn’t refer to the recommended state of charge. It refers to always keeping connected to a power source so that the battery pack can be kept at an optimum temperature. It’s saying “let the car‘s computer manage battery state of charge and temperature”. Which I think is spot on.

The technical answer is that a lithium ion battery pack has a limited number of deep charge cycles. Going from 80% to 20% will lengthen a batteries life. Going from 100% to 0% will shorten a batteries life. Fast DC charging can also damage a battery due to over shoot. That’s why DC chargers slow down once the battery has hit an 80% charge. In the early days of the Tesla Roadster, you could kill the battery in a few years by using the original Tesla DC chargers which didn’t lower the charge rate at 80% charge.

Over time engineers and scientists found ways to maximize battery life which is why we have the recommendation “charge to 80% for daily driving, charge to 100% if needed for a trip, keep your car plugged in when possible”.

 

[gnop1950]

Why do they speak about 80% in the handbook ?

I would imagine that testing has shown it to be optimal and perhaps a bit of a safety margin.

 

[epirali]

I charge my EVs only to the amount I need, and I definitely follow the recommendations of the manufacturer. They have a great deal of aging and longevity data in various conditions. So I tend to leave my EVs at 40% when idle, and only charge to what I know I need (almost never 100% unless as others have said I need the range). Then again I can and am going for "optimal" battery health. In all honesty after a few years I may have 5% more SOC then someone who just did the charge to 80% so it won't matter much, but I have issues!

But I see no reason to disregard the stated recommendation. Even Tesla with great deal of data has a "range" option that charges to battery to higher available charge, but doesn't recommend it for daily use. Batteries sitting at very high or very low SOC idle tend to degrade faster, so why do it?

And as for needing 100% charge I love the fact that Taycan has a departure time and will only start the charge to get to the range a little before you leave, minimizing the car sitting at idle. Why not use that if you need full range? It also preconditions the batteries.

 

[Dslev]

Why do they speak about 80% in the handbook ?

Page 79 of the Good to Know owners manual:

"Use the Timer or Profile function to program a maximum high-voltage battery charge of 85% for daily use of the vehicle without any long-distance driving."

 

[kort]

Page 79 of the Good to Know owners manual:

"Use the Timer or Profile function to program a maximum high-voltage battery charge of 85% for daily use of the vehicle without any long-distance driving."

in the '21 book 85% was lowered to 80%

 

[Mike in CA]

Here is the post from member 'Squiden' who works with satellite batteries on the subject.

I think it's really useful as it's someone in a highly technical industry where the numbers have been analysed from first hand experience in the field, rather than just hearsay etc.
I am taking his info as fact.

https://www.taycanforum.com/forum/threads/charging-best-practices.7081/post-101651

Thanks for your post. I frequently charge my wife's eTron with shallow charges to 80% to take advantage of our rooftop solar production and had wondered whether that might be an issue for battery life. It's good to know that it's not!

 

[Mike in CA]

This is the second time you've posted the same reference which doesn't make it any more relevant to the discussion. Leaving the vehicle plugged in doesn't necessarily mean it's charging to 100% as has been explained in posts in this thread from both @svp6 and @Windpower.

Both my Porsche and Audi are programmed to charge to 80% and that's the highest SOC they will achieve regardless of whether I leave them plugged in or not. Apparently it's the same with Tesla. To repeat, leaving the car plugged in does not equate to a recommendation to charge to 100%.

 

[Torv]

I charge to 85% unless I know I need to use more capacity that day.

Moi aussi!

 

[SwissTaycan]

I charge to 80% every day (and plug in every night no matter what I used that day). Only charge to 100% if I need it that day.

Two other thoughts:

1) I think there was a time when there was concern that leaving the Taycan connected to the charger for “extended” periods could have caused the dreaded dead 12V. Think that has become less of an issue since the big software update.
2) @HerrCooles has a good point (albeit written only in German): just like an iPhone can now tell you its “battery health” and what maximum capacity is (OK maybe not perfectly accurate) it does raise the question if in 2-3 years from now a dealer (or anyone with the right equipment?) will be able to assess the same on an EV. So the idea of “don’t care selling it in x years and charging to 100% every day” might not be the way to go and have some kind of an effect on the residual value.

 

[jlee504]

the problem with the onboard timer/profiles is you have to set a time and it manages to that time. I've been trying to set my minimum at 80% and my target at 80% thinking that might just get me to 80% directly but it doesn't seem to work that way.

 

[epirali]

the problem with the onboard timer/profiles is you have to set a time and it manages to that time. I've been trying to set my minimum at 80% and my target at 80% thinking that might just get me to 80% directly but it doesn't seem to work that way.

Not sure what you are trying to do. If you set the minimum to 80 and no timer it will charge to 80 as soon as you plug in. If you set your minimum to something else (say 40) then set a departure timer for 80% at time x then it will charge up to 40 immediately, then plan to be at 80% charge before time x (wait until time to charge needed).

 

[jlee504]

I just figured that out. I always read it as "Minimum" so it would keep going after that. Vs the Timer has a "Target"

so really you guys are just using the Profile without the Timer to get to the target as fast as possible.

Not sure what you are trying to do. If you set the minimum to 80 and no timer it will charge to 80 as soon as you plug in. If you set your minimum to something else (say 40) then set a departure timer for 80% at time x then it will charge up to 40 immediately, then plan to be at 80% charge before time x (wait until time to charge needed).

 

[epirali]

I just figured that out. I always read it as "Minimum" so it would keep going after that. Vs the Timer has a "Target"

so really you guys are just using the Profile without the Timer to get to the target as fast as possible.

I was/am not. I use the profile as a "minimum" and only set and activate the target for each trip for departure time. But you can also just use the profile minimum as your "I am ready to drive" percent.

 

[Mike in CA]

so really you guys are just using the Profile without the Timer to get to the target as fast as possible.

That's what I do; I don't bother with the timer. My profile is set for 80%, I plug in and it charges to that level. Since my charging times vary a lot based on the SOC of a car that isn't driven on a regular schedule and because I like to charge, when possible, during times when I'm getting good solar production, setting up pre-programmed timing would be totally impractical. I just plug in and unplug as appropriate.

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