Why has Tesla's charging advice changed

[coref1]

I've noticed with the latest software update that the daily charging recommendation on the screen is 50% to 80%. Before it was up to 90%. The Tesla charging FAQ says plug your car in as much as possible whereas much advice online recommends only plug in when necessary and keep the battery between 20% and 80%. Any ideas on what is correct because I'm confused.This is for the NMC battery .

 

[moa999]

And Elon has previously said even higher is fine for NCA/NCM chemistries.

 

[coref1]

And Elon has previously said even higher is fine for NCA/NCM chemistries.

View attachment 966432

The general advice for NMC batteries seems to be only change to 90%-100% when necessary for trips. This includes Tesla themselves so posts like the above from Elon causes confusion. To make matters worse now they have changed their advice for daily use.

 

[MC3OZ]

This Jeff Dahn video has good charging advice...

Basically try to cycle a Nickel battery between 45% and 75% during daily driving.

Advice is changing because research has revealed more about the causes of degradation.

On road trips the advice is just do what is convenient.

 

[paulp]

I would do what tesla recommend and ignore anything from Elon. I also suggest the advice is changed as they have found evidence that the changes improve the health or longevity of the battery during the warranty period. I really cannot think of any other reason. As for keeping the car plugged in, many people do not charge at home so cannot do that. Keeping it plugged in masks phantom drainage, and indeed that was the only valid reason tesla were able to give me for doing so. You can keep it plugged in but set the charge limit and it will not exceed it.

 

[Blue heaven]

Charge you NCM pack LR or Performance to what you need, if your panning to drive 300kms before the next charge session charge to 80%, if you plan to drive 340kms charge to 90%, if you plan to drive across the Barkly Highway and don’t have time to stop at the roadhouse charge to 100%. Enjoy the car.

 

[coref1]

Advice is changing because research has revealed more about the causes of degradation.

I thought that might be the reason.

 

[coref1]

Enjoy the car

Definitely doing that. Owned my M3 lr for just on a year now. Done 20k klms. Road trips to Tamworth, Coffs Harbour, Adelaide, Narooma and Wagga Wagga. Never thought I'd ever own a car this good.

 

[coref1]

would do what tesla recommend and ignore anything from Elon.

Will do thanks.

 

[MossDaddy]

Let's remember, Elons advice is dated 2019, lots has changed since then. Context is everything.

I also noticed the change today and it's confusing as a LR owner.

 

[rowdy]

I think the problem is there were lots of people who thought it was ok to leave the car sitting at 90% for long periods of time. High SOC for prolonged periods is what kills the batteries.

If you need 80 or 90% for your daily use then it's fine to set that but try to ensure the charge finishes just before you drive off so the car isn't sitting for a long time at these levels.

Maybe they should label 50% as low degradation as most people don't seem to register why 50% is also recommended for daily. If you only use 10-20% each day then 50% is a far better option. Then you'll have much lower degradation and have more range available when you need to take longer trips.

 

[Skurfer]

I seem to think its more around there is less regen braking around 90%. People are unplugging, driving then complaining why they are having to use their brakes more and that their regen is not working like it should. Might even catch a few people out every now and then.

 

[SL666]

I seem to think its more around there is less regen braking around 90%. People are unplugging, driving then complaining why they are having to use their brakes more and that their regen is not working like it should. Might even catch a few people out every now and then.

I actually think that might be a firmare thing - certainly if the battery is above 90 - the charge rate limiting (eg like how a supercharger rolls off) will limit regen, but i think the level of lift-off regen has reduced - e now have to brake to come to a stop at the hill near our house - where we could comfortably stop one-pedal before.

 

[DonSi]

I actually think that might be a firmare thing - certainly if the battery is above 90 - the charge rate limiting (eg like how a supercharger rolls off) will limit regen, but i think the level of lift-off regen has reduced - e now have to brake to come to a stop at the hill near our house - where we could comfortably stop one-pedal before.

I was wondering about this. My observation recently has been that I seem to have much less lift off retardation than I used to. And I need to brake into areas that I didn't before. The difference isn't huge, but certainly noticeable. Good to know it's not just me.

 

[Quickst]

If you only use 10-20% each day then 50% is a far better option

Exactly what I do. MYLR

Daily driving only uses 10-15% SoC, so there is zero benefit in SoC above 50% (Any benefit in terms of more available power at the motors at higher SoC is a moot issue in the daily driving context - and mitigated by the availability of the front motors). If I could easily do 40% I would, except that auto stop charge limit is not less than 50%. I could manually stop at 40% but that reduces the charging convenience

No issues with Regen braking even on the several mornings of 4C after being parked for over 10hrs.

Even with the above practice the dwell time at 50% is no more than a few minutes to maybe 1 hr

On the hottest days of the year, I think I'll manually stop at 40%.

Whatever the reasons for the change in Tesla charging recommendations , it has not required me to change what I'm doing.

Remember 80% is the upper limit recommendation. 50% is also one of the recommendations.

 

[coref1]

I currently charge once or twice a week as I'm concerned about the wear on the connectors if I plug in more often. To keep my charge between 50% and 75% I will have to charge more often. What's everybody's point of view wear on the connectors?

 

[Borgy]

What's everybody's point of view wear on the connectors?

No idea, plug seems to slip in without too much hassle, We are using chargehq so car is plugged in whenever it's home, Haven't given it too much thought, if it does start wearing out the temp will increase and the car would know about the wear.

Maybe should lookup the plug specs and what sort of insert/remove cycles they are rated for. I suspect it would be like > 10000

 

[Vostok]

Daily driving only uses 10-15% SoC, so there is zero benefit in SoC above 50%

Well there is, if you have rooftop solar and use your car to soak up the excess. If you eschew the opportunity to charge above 50% when it is sunny, you might rue that the following week if it is cloudy.

I charge my car up to 90% using excess solar. If there are extended poor solar conditions, that 90% will get drawn down over the next week. With normal city usage, I don’t think it’s ever gone down below 50% before good solar conditions have returned.

 

[Quickst]

I charge my car up to 90% using excess solar

Never at home except for weekends to soak up annual excess of 20,000kWh , even then car often not at home to exploit solar.

Easy enough for me to see weather predictions to adjust max SoC.

 

[cafz]

I currently charge once or twice a week as I'm concerned about the wear on the connectors if I plug in more often. To keep my charge between 50% and 75% I will have to charge more often. What's everybody's point of view wear on the connectors?

I plug in every night, I'm not concerned about wear on the connectors - the Mennekes plug & socket design seems pretty sturdy.