Charging to 100%? Is it that bad?

[Xdeanyy]

Hi all,

Does anyone here regularly charge to 100%?

I have to rely solely on public charging which is fine but I find it hard to stop charging at 80/90% and leaving it. Generally want to charge to 100% if I can, even if I don't need it. Maybe it's a bit ocd.

I'm a company car / lease holder. Is there any serious issues to me charging to 100% every time or is it just a myth?

Battery degradation may increase but I imagine this may move the needle by a few % over a few years. Once my lease is up I just get to choose a new car because it's a company car scheme.

What is everyone's thoughts?

Edit* I have a MYLR non LFP

 

[Stuart1714]

Do you have a LFP battery, which are in some Teslas? If you have a LFP Battery, then Tesla recommend to charge to 100% anyway.

If you are unsure if you have a LFP battery, Tesla say:

”To determine if your vehicle is equipped with an LFP battery, navigate to Controls > Software > Additional Vehicle Information. If your vehicle is equipped with an LFP battery, "High Voltage Battery type: Lithium Iron Phosphate" is listed.”

 

[Xdeanyy]

Do you have a LFP battery, which are in some Teslas? If you have a LFP Battery, then Tesla recommend to charge to 100% anyway.

If you are unsure if you have a LFP battery, Tesla say:

”To determine if your vehicle is equipped with an LFP battery, navigate to Controls > Software > Additional Vehicle Information. If your vehicle is equipped with an LFP battery, "High Voltage Battery type: Lithium Iron Phosphate" is listed.”

Hi I have just edited it...

No I don't have LFP and Tesla recommend 80% for daily

 

[spooksman]

If I understood your post correctly, it's a lease car, so going back to the lease company within a couple of years?

If so, I wouldn't worry - "not your problem".

 

[Xdeanyy]

If I understood your post correctly, it's a lease car, so going back to the lease company within a couple of years?

If so, I wouldn't worry - "not your problem".

Exactly correct

 

[ACarneiro]

That would depend on the conditions of the lease.
IANAL but surely there must be some provision on the conditions to ensure that you take reasonable care of the car. It could be argued that intentionally stressing the most expensive component in the car against the manufacturer’s recommendation might have some sort of consequences…

 

[jjrandorin]

Exactly correct

If the thought process is "its a leased car, not my problem", I dont even get the creation of the thread to ask the question. If you dont have a LFP enabled tesla, the car will remind you not to charge to 100% if you have it set there for more than 2-3 charges in a row, but you can ignore it.

There isnt any reason to care about whatever the battery degradation would be, because "its a leased car, not your problem", so whether it adds to the degradation or not doesnt really matter.

Unless you are running a taxi service or something, if you had a battery warranty issue during your ownership period, its likely the battery warranty would still be honored (again as long as you were not fast DC charging daily or something that would look like abuse / commercial use). We know for 100% fact that charging batteries to 100% extra degradation based on how battery chemistry works.

We also know pretty well that model S / X results do not mirror model 3/Y results, so whether the car battery is "babied" or not the expectation should be for approximately 7-10% battery degradation over the first couple of years. Hypothetically, if you charged to 100% regularly and the car ends up having 20 miles total less range, it wouldnt matter in the slightest to you, because "its a leased car, not your problem".

 

[johnbol1]

If you are charging the using and getting back down to 80-85 shortly there after, no major
worries.
LFP doesnt like to be sat in a fully charged state

 

[spooksman]

If so, I wouldn't worry - "not your problem".

I should say that I don't necessarily endorse this view (I treat my lease car like it's my own!), but one of the perceived 'benefits' of a company/lease car is that you are giving it back.

In the old days, when you bought a second hand car that was an 'ex' company car, you pretty much new it had been used hard, but also serviced correctly.

 

[STS-134]

I should say that I don't necessarily endorse this view (I treat my lease car like it's my own!), but one of the perceived 'benefits' of a company/lease car is that you are giving it back.

The residual value accounts for the fact that it's been used before being returned. If they want to give credits for less than normal degradation, they should have written this into the terms of the lease. Otherwise, you're just making the car less useful to you over the time you've leased it and you're not getting any benefit out of doing it. If I'm renting/leasing a car and I find it more convenient to charge to 100%, I'm just going to do it. The payments I'm making to use the car account for depreciation, and battery degradation is one of the things that causes the value of a car to decrease. I've already paid for the degradation I cause, and I'm paying a flat rate for this stuff, so...

 

[boombap]

The reason not to charge fully is a complicated one involving chemical reactions that can occur in the battery cells themselves at very high and very low charge rates, this can cause several different issues which will cause physical changes to the chemicals in the battery and degrade the cell. Regular charging to 100% will absolutely degrade the battery faster than charging to 80 or 90%. Going to 100% is fine if you’re going to drive it immediately, the bigger issues come from charging to 100% and then not driving it for a week leaving it that full.

I also rely on public charging and often push it to 93% because I know by the time I get home I’ll be back at or below 90%

 

[Whyone]

I'm in the 'treat the car with care and respect' camp, whatever the ownership situation.

My leased M3 got treated just the same as my current personally owned car.

 

[jjrandorin]

I'm in the 'treat the car with care and respect' camp, whatever the ownership situation.

My leased M3 got treated just the same as my current personally owned car.

I am too, but I am not judging people who arent. I realize fully my other post in this thread may sound that way, but its not like "I leased the car so I didnt have to think about any of that" is a rare thought process or something. Thats one of the reasons I would never willingly buy a lease return vehicle unless I was the one who leased it from new, but thats a "me" issue.

Its also (for example) the reason why, when I was house hunting, I told my real estate agent that I was not interested in considering any house that looked like it was being "flipped" by a house flipper. I would rather have a house that was someones home (they lived there for a while) than someone who was focused on making it "look" nice with cheap finishes etc to make a profit.

I will repeat again, however, thats a "me" issue, I am not judging people who do it, I just didnt want a home like that, or a previously leased vehicle.

 

[STS-134]

I am too, but I am not judging people who arent. I realize fully my other post in this thread may sound that way, but its not like "I leased the car so I didnt have to think about any of that" is a rare thought process or something. Thats one of the reasons I would never willingly buy a lease return vehicle unless I was the one who leased it from new, but thats a "me" issue.

Same thing with buying ICE cars formerly used as rentals. Just gotta assume that people drove them like they stole them. I wouldn't deliberately cause excessive amounts of battery degradation on leases/rentals but my calculations would change a bit. With my personal car, I don't charge it to a certain level above 50% unless I'm sure I need to use that capacity. For a rental, I'd charge it if I thought there was a pretty good chance I might use the capacity but was still a bit unsure and I wouldn't stress about trying to get the additional charge in there at the last minute in case I suddenly have to go somewhere. I wouldn't make a big deal about letting a rented or leased car sit at 70% or 80% SoC for a day as a big deal whereas on my personal car, I would.

 

[UkNorthampton]

Some people wouldn't rev their leased ICE cars above a level while still cold. Others rev the nutella off their own cars when cold. I think it's a similar thing. I would probably go to 90/95/100% depending on need and how much charge the car will use journeying back to Supercharger & heating up in the morning. Personally I generally only leave my own nickel M3LR at 100% for a few hours, sometimes overnight, normally below 90%, ideally 50-80%. Personal choice. In 3-5 years lease, I wouldn't imagine any big consequences.

Extreme use like Out Of Spec & Bjorn Nyland just shaves a couple of % off battery life over many years. They are using the cars on tracks, 1000 km speed runs, mostly Supercharging with little AC charging at home. Newer cars with newer Battery Management System updates (which will also apply to older cars, but can't make up for past use) should be even better. Rev it to 6000 from cold if you want, the battery will probably last longer than an ICE engine that's been pampered or the automotive parts of ANY car.

 

[BitJam]

Some people wouldn't rev their leased ICE cars above a level while still cold. Others rev the nutella off their own cars when cold. I think it's a similar thing. I would probably go to 90/95/100% depending on need and how much charge the car will use journeying back to Supercharger & heating up in the morning. Personally I generally only leave my own nickel M3LR at 100% for a few hours, sometimes overnight, normally below 90%, ideally 50-80%. Personal choice. In 3-5 years lease, I wouldn't imagine any big consequences.

Extreme use like Out Of Spec & Bjorn Nyland just shaves a couple of % off battery life over many years. They are using the cars on tracks, 1000 km speed runs, mostly Supercharging with little AC charging at home. Newer cars with newer Battery Management System updates (which will also apply to older cars, but can't make up for past use) should be even better. Rev it to 6000 from cold if you want, the battery will probably last longer than an ICE engine that's been pampered or the automotive parts of ANY car.

Great post, slight correction. Kyle from Out of Spec does a lot of AC home charging. Another YouTuber, CYBRLFT only did supercharging and his battery died after 140K miles. Tesla told him the early failure was due to exclusively supercharging.

 

[Drew57]

I also rely on public charging and often push it to 93% because I know by the time I get home I’ll be back at or below 90%

I have always done something similar, especially with places I visit regularly & know how much will be consumed by the time I park up. The only times I go beyond 90% are at a SuC where I am continuing a journey.

Model 3LR batteries had lost just over 6% compared to new after 32 months & were nearly always filled to between 80-90%. That seemed reasonable.

 

[Xdeanyy]

To clarify, the question really is.. how much more degradation am I to expect if I charge to 100% quite often and leaving it say just over 90% for a day or two?

I don't want to kill the car and I'm not planning to abuse it just because it's a lease.

Had it to stop charging at 85% on a public charger earlier but I was going to be a few more hours than planned, so I just thought ah well may as well go to 100%.

If it's say extra few % degradation over a couple years then that's fine but if it's a serious issue then naturally I won't.

 

[Rooster6655]

Hi all,

Does anyone here regularly charge to 100%?

I have to rely solely on public charging which is fine but I find it hard to stop charging at 80/90% and leaving it. Generally want to charge to 100% if I can, even if I don't need it. Maybe it's a bit ocd.

I'm a company car / lease holder. Is there any serious issues to me charging to 100% every time or is it just a myth?

Battery degradation may increase but I imagine this may move the needle by a few % over a few years. Once my lease is up I just get to choose a new car because it's a company car scheme.

What is everyone's thoughts?

Edit* I have a MYLR non LFP

As Elon has mentioned before charging to 100% isn’t efficient due to regen but not that is a problem with it.

When I had to use public charging I would do 100% where possible and never noticed any issues over 2 years.

 

[boombap]

To clarify, the question really is.. how much more degradation am I to expect if I charge to 100% quite often and leaving it say just over 90% for a day or two?

I don't want to kill the car and I'm not planning to abuse it just because it's a lease.

Had it to stop charging at 85% on a public charger earlier but I was going to be a few more hours than planned, so I just thought ah well may as well go to 100%.

If it's say extra few % degradation over a couple years then that's fine but if it's a serious issue then naturally I won't.

That’s the wrong question.

Lithium ion cells suffer from chemical reactions at high states of charge, which do a couple things. The battery cell contains what is called a “jelly roll” basically two sheets of rolled up metal foil, one copper, one aluminium, both are coated with a thin layer of a paste containing the lithium, nickel, manganese, cobalt, etc. If you charge to 100 it begins to cause cracking and other damage in this paste, the more cracks it gets the less energy it can store. There is a secondary issue if something called dendrites which is a process where the chemicals deform and grow spikes, these spikes can pierce the foils in the jellyroll, not only is this bad, it’s potentially dangerous and can lead in very rare and extreme cases can lead to battery short circuits and/or fires.

Tesla themselves, and almost every other vehicle manufacture explicitly recommend not charging to 100% unless needed for a road trip for this exact reason. The same reason Apple have implemented a smart charging process for iPhones where once it has worked out what time you wake up in the morning, it’ll only charge to 80% overnight, then a short while before you wake will charge to 100% so that the battery spends as little time as possible at that maximum charge which will cause problems with accelerated degradation. How much that is is impossible to put a generic number on, it’ll depend if you’re doing it at a supercharger or at home, if you’re leaving it a 100% for a day or a week. regardless, however you do it your battery will degrade faster that someone charging to 80%. Furthermore, it‘s just a waste of time. Above 90% you’ll get a max 50kWh charge rate, so if you’re clogging up a fast charger at a slow speed, it’s just poor etiquette.

Just follow the recommendation of the manufacturer and charge to max 90 unless you need it for a long journey. If as per your original post you're having issues with that because of your OCD, that’s a different issue to discuss with your healthcare professionals.