Model 3 recommended charge limit?

[smorgasbord]

I know this has been discussed and documented to death for Model S & X, but Model 3 presumably has different battery chemistry and management systems.

What's the current thinking on "safe" daily charge limits? The graphic on the charging screen suggests something between 50% and 90%. I currently have it set to about 85%. Some people say 70%-80% is the sweet spot, others say 90% is just fine, especially given the current Model 3 battery warranty.

What say you, and why?

 

[Veritas1980]

I would say it is the same recommendations as for the S and X.

There may be a difference in battery chemistry, but I doubt it is something that radical changes the behavior of lithium batteries, or someone would have made quite a fuss about it I would imagine.

So I say you should charge to what you feel comfortable with.
If you drive a lot or you often need to run some extra errands, keep it at 90%.
If you don’t drive a lot, you can baby the battery (that’s what I do) and keep it at 70-80% on a daily basis, and charge 90 or 100% for trips.

To be honest, in the end I don’t think it makes much difference. I just like to know that I took best possible care of the battery.

 

[Falcon Wings]

Read an article somewhere, where an owner reached out to battery researcher. Verdict was 70% is optimal and can increase the life of battery.

 

[TexasEV]

Don't obsess over this. After 5 years of the Model S there hasn't been shown to be a meaningful difference in range based on how people charge. Battery researchers can find statistically significant differences, but that doesn't mean there is a practical difference. If the possibility of a couple of miles difference in range after many years really matters to you, you probably bought the wrong car.

 

[Kenz]

Charge to 70% unless you need more on a daily basis or for trips.
That is the expert recommendation I read.
Take care of your battery and it will have a long life.

 

[TexasEV]

You don’t need to take care of it. The battery management system will take care of it. The only reason there is even a choice to charge less than 90% for daily use is the slider gets around the stupid EPA rule of averaging the range if an EV has two settings. The Tesla firmware no longer has two settings so only the 100% range is reported. Remember the early firmware had two settings—daily and trip— and I think daily was 92%.

I’ve charged my Model S 60 daily to 90%, except for 100% charges 4 or 5 times/ month, and after 4 1/2 years I have only lost 4% of original battery capacity (200 miles compared to 208 when new). Much of that was in the first year as is expected.

 

[smorgasbord]

OK, so in response to my own query, I dug up this old Tesla blog post from 2006. Yeah, I know, it's for original Roadster battery chemistry, which is why my original question here was about Model 3, but here goes:

A Bit About Batteries

There is a huge difference in cycle life between a 4.2V/cell charge (defined by the manufacturers as “fully charged”) and a 4.15V/cell charge. 4.15 volts represents a charge of about 95 percent. For this reduction of initial capacity (5 percent), the batteries last a whole lot longer. Unfortunately, further reduction of charge has a much smaller benefit on cycle life.

So that would say that charging to 90% is not a problem at all, and may even be being overly safe. Martin Eberhard in the blog continues:

The other significant factor that affects calendar aging is the charge state of the battery during storage. At higher charge states cells lose capacity faster. This is a second reason why we have limited our maximum state of charge to 4.15V/cell instead of 4.2V/cell. We also offer the driver the option of charging to only 3.8V/cell (~50 percent) or 4.10V/cell (~90 percent) to further extend calendar life if the full vehicle range is not needed on the next few trips.

So, Roadster limit is at 90% for normal charging and 50% for long term storage.

How/Why is this different for Model 3? If anything, I'd expect the newer chemistry (and potentially more sophisticated BMS) to handle things with even less fuss

 

[widodh]

Don't obsess over this. After 5 years of the Model S there hasn't been shown to be a meaningful difference in range based on how people charge. Battery researchers can find statistically significant differences, but that doesn't mean there is a practical difference. If the possibility of a couple of miles difference in range after many years really matters to you, you probably bought the wrong car.

Indeed. I’ve driven 200,000km with my S85 and I’ve always charged to 90% and didn’t think twice charging to 100% when I thought it was needed or wanted the extra buffer.

Degradation is still very low, about 7%

 

[Lasttoy]

Don't ever worry about battery charging. I have 110k on my 2013. If I'm going tripping, I charge to max. Around home I keep about 175 miles. After 4 years, zero affect on my batteries. Not one problem so far, zero.

 

[smorgasbord]

I have 110k on my 2013....After 4 years, zero affect on my batteries.

I'm certain your range has decreased. The issue here isn't so much battery problems, but reducing the range prematurely.

 

[Lasttoy]

Wrong, I push it to max right side, it fills up. I leave home. Go on trip. I have to push it to max because there are so few chargers on east coast and Florida. I was in Charleston last weekend. Got back to Savannah with 4 miles left.
I can't figure percentage of loss. I move the line as far as it will go. Since I got it used, I don't know January 2013 number, but I know what everyone says on here. It might have gone to 265, 275 in 2013, but I push it as far as I can. I was in Orlando, made mistake, went shopping, got low. Went to SC, lady refused to give me charge. Finally they gave me 90 miles to get home. I need full charge.
To lose a tiny percentage would seem normal. I have visited 20 states, talked to a lot of folks at chargers. They don't seem to be concerned.

 

[EV-lutioin]

From the man himself:

 

[insaneoctane]

From the man himself:

View attachment 272128

But, "best" might be better by 1/10 of 1%.....which is better 99.999% or 99.998%? Well, 99.999% is...... But not necessarily meaningful.

 

[03DSG]

Jeff Dahn

Tesla battery expert recommends daily charging limit to optimize durability

 

[Glamisduner]

Draining the battery too low can also be hard on it I think. Quick charging can be hard on it too. Best is probably keeping it between 50 and 70% at all times, but can anyone actually do that? 30-80% will reduce degradation pretty well so that's probably what I will aim for on an extended range vehicle. Of course, I have to wonder if there is also some reserve capacity based on what people are actually reporting for battery degradation which makes calculating anything more of a guess.

 

[insaneoctane]

Draining the battery too low can also be hard on it I think. Quick charging can be hard on it too. Best is probably keeping it between 50 and 70% at all times, but can anyone actually do that? 30-80% will reduce degradation pretty well so that's probably what I will aim for on an extended range vehicle. Of course, I have to wonder if there is also some reserve capacity based on what people are actually reporting for battery degradation which makes calculating anything more of a guess.

The data from the google spreadsheet (see article HERE), the more you supercharge, the better !?

"...surprisingly, frequent Supercharging (twice a week to daily) appears to actually be beneficial in preventing battery degradation."

 

[Glamisduner]

The data from the google spreadsheet (see article HERE), the more you supercharge, the better !?

"...surprisingly, frequent Supercharging (twice a week to daily) appears to actually be beneficial in preventing battery degradation."

If tesla calibration software is anything like accubattery I use for my phone, charging to 100% seems to help the software to accurately calibrate remaining phone battery capacity, but I don't think it actually helps the battery. I wouldn't be surprised if the Tesla software calibration is helped by supercharging or charging to 100% as well. But I doubt supercharging is actually better for the battery. Of course, this is just speculation I don't know anything about how their software works, but wanted to point out that with batteries the only way to really test them is to drain to a low level then fully charge them a couple times to estimate actual holding capacity, which is likely what happens when people need to visit superchargers

 

[jym626]

So, any update on thoughts for how to keep the battery in its best shape on the 3?

 

[EV-lutioin]

The data from the google spreadsheet (see article HERE), the more you supercharge, the better !?

"...surprisingly, frequent Supercharging (twice a week to daily) appears to actually be beneficial in preventing battery degradation."

And contrary to what most people have said on this thread about 80% vs 90%, it says this:

"...but it seems that 90% charge level appears to be the ideal daily charge level."

 

[Rocky_H]

Oh jeez. We're starting this whole discussion all over again because it's a different model of car?

What's the charging limit recommendation for the one with the white seats?