Range Loss Over Time, What Can Be Expected, Efficiency, How to Maintain Battery Health

[afadeev]

I bought Model 3 standard range plus with an advertised 305ml range but in the month I've had it, it never shows more than 275ml range. Having spoken to Tesla three times about this they've said the 305ml range is 1. a battery hardware upgrade (if it is I don't have it). 2. It's a software update that will happen at some point (plausable). 3. It's a 305ml range car but shows 275 ml range because of my driving style in cold weather (unlikely). Surprisingly I'm confused, and thoughts?

Cold weather absolutely adversely effects range in EVs. As does expedient highway driving.
The colder it gets, the more battery energy is used up to keep the battery pack within operating temp range, never mind the humans.

Having said that, Tesla's range estimates are a bit optimistic. My car came with the claimed 300 mile range (or 305, or 315, depending on what day you check Tesla's web site), but I never got to see more then 285, which is close enough for me.

Impact Of Cold Weather On EV Models' Range: Report

Some EVs fare much better than others in cold temperatures, but no car is immune from temporary winter range loss. If you experience cold temps, check this out.

insideevs.com

 

[sightman]

Here is a link with some comparisons out of UK.

Average Electric Car Range in the UK 2023

Here is range data on all electric car models available in the UK, including a ranking of the electric cars with the longest range.

www.nimblefins.co.uk

300 miles out of a Model 3 SR+ sounds like a pipe dream. It has a hard enough time achieving the EPA mileage here in the US which is more conservative than WLTP.

 

[GeoG]

Cold weather absolutely affects the range. See below pics from TeslaFi on range/ energy used for the same drive 1 week apart.
On 01/12/2022 the outside temp was in the 60's F
On 01/19/2022 the outside temp was in the 30's F

Note: This is on a M3 LR

 

[GtiMart]

When you say the car "shows" 275 miles of range, where are you looking at? On the main screen, the "miles remaining" indicator is based on energy in the battery using the EPA consumption constant. It has nothing to do with how you drive nor temperature for the most part. The thing is, the car's BMS cannot estimate the energy in your battery with 100% precision, it's an estimate. Also, just putting the slider to 100% without actually charging to 100% means the BMS is trying to estimate how much energy there would be if you charged up there. There is a significant difference between that estimate and the real value once you charge. That estimate seems to be worse for people that live in cold climates, when the battery is cold.

At the end of the day that's just an estimate based on EPA. Real world range is what matters, so you shouldn't care what that number says.

 

[Mike Hawk]

I know I know, ABC. But how bout this scenario?

I start my day @ 80% state of charge and consume ~20% one way to kid's school and my "work". So currently in the evening I arrive home anywhere from 40-45% SOC and it takes ~2 hours to get back up to 80% via 48a HPWC.

My "work" is actually my dad's house and I have easy access to his wall panel and I have the leftover outlet and breaker for when I used to do NEMA 6-20 at my house before I had the HPWC. This got me to thinking. I could easily do a quick install and then have the mobile charger at my work and I could go from 60 to 80% in ~3 hours. Or heck, rock a 14-50 and cut that charge time down to ~1.5 hours.

Neither charge time(s), nor diminished power due to lower SOC while driving near 40%, nor range are of any concern. I really have no need to charge at work, other than if it'll help the life of my batteries.

So, is it better to min/max or yo-yo throughout the day? Any studies done to say one way or the other or is this just a rounding error?

 

[GtiMart]

Since you're not interested in performance nor range, I presume it's battery health you're looking for. In general the literature favors smaller (shallower) charges and staying around 50%, although that is not specific to Tesla chemistries. Instead of 80-40, you might want to be a 70-30

Now, although literature favors one thing, you would also need to figure out if the gain is really worth it. If you save 1 mile of range over 5 years of having the extra hassle of plugging twice per day instead of once, is it worth it? I'll go out on a limb here and say it won't make a significant difference if you plug once or twice per day. Extremes make significant differences: staying at 100% for long, leaving the battery empty, doing 0-100% charges all the time, leaving the battery at very high temps all the time etc.
So my personal opinion? Do whichever is simpler for you.

 

[jjrandorin]

I know I know, ABC. But how bout this scenario?

I start my day @ 80% state of charge and consume ~20% one way to kid's school and my "work". So currently in the evening I arrive home anywhere from 40-45% SOC and it takes ~2 hours to get back up to 80% via 48a HPWC.

My "work" is actually my dad's house and I have easy access to his wall panel and I have the leftover outlet and breaker for when I used to do NEMA 6-20 at my house before I had the HPWC. This got me to thinking. I could easily do a quick install and then have the mobile charger at my work and I could go from 60 to 80% in ~3 hours. Or heck, rock a 14-50 and cut that charge time down to ~1.5 hours.

Neither charge time(s), nor diminished power due to lower SOC while driving near 40%, nor range are of any concern. I really have no need to charge at work, other than if it'll help the life of my batteries.

So, is it better to min/max or yo-yo throughout the day? Any studies done to say one way or the other or is this just a rounding error?

I havent seen anything that says charging multiple times during the day is going to make any difference at all in relation to charging once at the end of the day for the same amount. I have seen info that as far as charging cycles go, there is no benefit to running it down before you charge it back up for this type of battery. 10 charges of 10% are the same as 1 charge of 0-100% as far as battery cycles go.

Given what you laid out as your object, I dont think it makes any difference at all, and is not worth going through and setting up charging at "work".

 

[Mike Hawk]

Well, I could offset a couple $ in savings by charging at pop's <evil grin>

 

[jjrandorin]

Well, I could offset a couple $ in savings by charging at pop's <evil grin>

Rofl! He "should" just charge you for it, if you do that, but im guessing that wouldnt happen (saying that as someone who myself is still paying for my 28 year old daughters cellphone on my mobile plan, even though she has a full time decent corporate job )

 

[tonyhny]

I lose 4-6 miles for not driving the car. Cold weather is horrible for this car. My 310 rated gives me around 250 now from my Stats app.

 

[CarlThompson]

I can not see any real difference in how Tesla would handle the below 70% capacity failed battery vs a broken one that perhaps had 90% capacity left.

The difference is that your statement that I was disagreeing with was that Tesla would replace a worn out battery with one at around the same degradation level as the original battery. So obviously there is a big difference between a battery replaced at below 70% and and a battery that is replaced at 90%. Here is what you wrote (emphasis mine):

If you try to kill your battery and it reaches 69% or less, Tesla is only obliged to give you a battery that holds 70% the day the warranty expires. So they will give you a remanufactured battery that is at the same degradation level as your battery before it got ”faulty”

I am disagreeing with your statement that Tesla "will give you a remanufactured battery that is at the same degradation level" if you manage to get your battery below 70%. So far you have presented zero examples of Tesla doing that.

Perhaps there is a language issue and you meant to say that Tesla MIGHT do that but what you actually said is that Tesla WILL do that.

 

[jjrandorin]

The difference is that your statement that I was disagreeing with was that Tesla would replace a worn out battery with one at around the same degradation level as the original battery. So obviously there is a big difference between a battery replaced at below 70% and and a battery that is replaced at 90%. Here is what you wrote (emphasis mine):



I am disagreeing with your statement that Tesla "will give you a remanufactured battery that is at the same degradation level" if you manage to get your battery below 70%. So far you have presented zero examples of Tesla doing that.

Perhaps there is a language issue and you meant to say that Tesla MIGHT do that but what you actually said is that Tesla WILL do that.

What they will do (which is what they have been doing) is provide you with a battery that is supposed to remain above the degredation thresshold until the end of the warranty, whenever that is for your particular pack. What they will not do, "give you a new battery" as there are not any examples of that I have seen.

If you manage to get your battery below the 70% thresshold from degradation in year 4, they would give you a battery that is expected to remain above that 70% thresshold for 4 years, which is the remainder of your battery warranty. If your battery failed because of some reason other than battery degradation, and it had 15% degradation already, the expectation should be that you would get a battery with similar degradation (in this made up example 15%), not a new one.

Two different examples (one with 70%+ degradation, one with a failed battery due to something else other than degradation). I believe model S owners have seen both examples.

What we normally see, is people being "incredulous" that they are not getting a "brand new" battery as that is what people tend to expect.

As far as the "abuse" aspect, I have no inside knowledge on that whatsoever, but think that is likely pointed at someone who is (for example) running a taxi / turo service and supercharges multiple times a day or someone who attempts to wire the car to use it as a mobile powerwall, or removes the pack and uses it as home storage, then tries to put it back in the car and bring it to get it replaced under warranty.

I doubt very seriously any real "good faith" usage, even if someone supercharged almost daily, would constitute "abuse".

 

[CarlThompson]

What they will not do, "give you a new battery" as there are not any examples of that I have seen.

I did not say Tesla would give anyone a new battery (though there are some possible examples of that I have read about). The argument here is that I have seen no evidence to suggest that Tesla would purposefully give someone whose battery is replaced for going under 70% a replacement near the same degradation as @AAKEE seems to be saying:

AAKEE said:
If you try to kill your battery and it reaches 69% or less, Tesla is only obliged to give you a battery that holds 70% the day the warranty expires. So they will give you a remanufactured battery that is at the same degradation level as your battery before it got ”faulty”

 

[AAKEE]

What evidence do you have that Tesla actually does what you describe or are you just making things up to scare? I don't doubt they COULD do that but I've never heard that they DO. For the warranty replacements I've heard of Tesla has supplied a replacement battery that worked similarly to new.

Its all clear that the warranty warrants 70% capacity until 8 years and xxyyzz miles/km. If you try to kill your battery and it reaches 69% or less, Tesla is only obliged to give you a battery that holds 70% the day the warranty expires. So they will give you a remanufactured battery that is at the same degradation level as your battery before it got ”faulty” and if you tried to wear it out you probably get one that barely manage the 70% the day the warranty expires.
So after 8 years your stuck with a much worse degradation then the people that did take care of the warranty.

Kill —> get a new one doesnt work.

I did not say Tesla would give anyone a new battery (though there are some possible examples of that I have read about). The argument here is that I have seen no evidence to suggest that Tesla would purposefully give someone whose battery is replaced for going under 70% a replacement near the same degradation as @AAKEE seems to be saying:

AAKEE said:
If you try to kill your battery and it reaches 69% or less, Tesla is only obliged to give you a battery that holds 70% the day the warranty expires. So they will give you a remanufactured battery that is at the same degradation level as your battery before it got ”faulty”

So except for my "will" misstake we agree that tryiong to kill the battery to get e new one is a bad idea ? Good.

 

[brjr]

I come and go from home 3 -4 times a day. I most often engage the mobile charger when i pull into the garage unless the 'Estimated Remaining Charge' at the top of the screen (or whatever that is called?) is approx 220 plus. Following this practice i am able to go weeks at a time without a SC. Is that ok for the battery or is that frequency of charging negatively impacting the battery?

 

[dmurphy]

I come and go from home 3 -4 times a day. I most often engage the mobile charger when i pull into the garage unless the 'Estimated Remaining Charge' at the top of the screen (or whatever that is called?) is approx 220 plus. Following this practice i am able to go weeks at a time without a SC. Is that ok for the battery or is that frequency of charging negatively impacting the battery?

Totally, 100% OK. In fact, preferred. Optimal, even.

Follow the ABCs of Tesla: "Always Be Chargin'" ...

A plugged in Tesla is a happy Tesla.

 

[brjr]

Thanks! Good to hear.

 

[Dave EV]

Neither charge time(s), nor diminished power due to lower SOC while driving near 40%, nor range are of any concern. I really have no need to charge at work, other than if it'll help the life of my batteries.

So, is it better to min/max or yo-yo throughout the day? Any studies done to say one way or the other or is this just a rounding error?

Lithium-ion battery life studies show the following things are good for extending the life of batteries (in no particular order):

• Batteries that are operated and stored at a cooler temperature last longer than hotter batteries (just don't try to charge them too fast when really cold)
• Batteries that experience shallower cycles provide more effective cycles than deeper cycles (eg. one 100-0-100% cycle is harder on the battery than 5 60-40-60% cycles.
• Batteries that are charged slower last longer (down to a point - for level 2 / AC charging, it doesn't matter, it's all "slow" compared to DC charging).
• Batteries that are stored at a lower state of charge last longer than batteries stored at a higher state of charge - also why you don't want to charge over 90% regularly as the rate of capacity loss over time at high SOC gets pretty bad as you get over 100%.

@AAKEE has posted quite about the last point (called calendar life of batteries), in particular and some studies regarding NCA batteries show that the rate of capacity loss has a bit of a step up in the rate of capacity loss between 55-60% SOC.

Now you're looking at 3 different possible scenarios:

1. 80-40-80% cycles (keep on doing what you're doing)
2. 80-60-80% cycles (charge 2x as often)
3. 60-40-60% cycles (charge 2x as often, but only to 60%)

Option 3 would be best for battery life - smallest cycles and lower average SOC (50% instead of 70%. To optimize it further you might try charging to only 55% or 50% daily.

 

[AAKEE]

I really have no need to charge at work, other than if it'll help the life of my batteries.

So, is it better to min/max or yo-yo throughout the day? Any studies done to say one way or the other or is this just a rounding error?

Dave Ev is right, I just ad a little:

If you would like to minimize degradation, there is some simple rules. If not, Teslas basic simple rules will bee good enough to not have too much degradation. But one of the main ideas with Teslas advice is simplicity, not to preserve the battery by adding complicated rules and advice.

To minimize degradation:
- Charge daily, or even more often.
- Charge “just in time” = charging complete not long before the drive.
- Stay low. Do not charge to a higher SOC than you need.

Low SOC is the best to keep calendar aging low. Low temperature is also much better than high temps, but most people can not change the ambient temps. Insulated garage or maybe a carport to hide under during hot days might be good.
Low SOC is the best for cycles, cycles at low SOC wear less.
Small cycles wear much less than large cycles.

For NCA lithium batteries there is tests showing that a 10% cycle around 30% SOC(ie 35-45%) only cause a 1/4 to a 1/5 of the wear a 10% cycle cause around 70%. 600 equivalent full cycles in each test(=6000 10% cycles) Caused around 2% degradation at 30% SOC and 10% at 70% SOC.
For a M3LR this equals about 210.000km/130.000mi, with the choise of 10% or only 2% degradation for the cyclic aging part of the degradation. (10% cycles is quite small and require many charges so it might not be applicable for most people, but as an example it might be understandable).

Calendar aging, if the car is left charged with high SOC each night, for example 80% SOC the calendar aging part of the degradation might end up at about 5% after one year from new. If the car instead is left with low SOC during the night and is charged just in time the calendar aging might be cut in half.
If high SOC is needed the calendar aging still will be very low if the “just in time” approach is used.

I have followed the above, my M3P is a little more than one year since pick up, and the degradation do not really show clearly yet. Still full range on each full charge, and the battery capacity per the BMS is more or less the same as the day after delivery after 32000km.

 

[CarlThompson]

So except for my "will" misstake we agree that tryiong to kill the battery to get e new one is a bad idea ? Good.

So you're saying you just misspoke? I would have preferred that you just admitted that you made a mistake right from the start! It would have made this conversation a lot smoother without a bunch of people attacking me to defend you erroneously.

Yes, we agree that purposely abusing a good battery for no reason is "bad." But honestly I don't think it would be that bad if someone's battery were already at say 71% with 6 months left on the warranty and they tried to use their battery enough (within the rules) in that final time to get a replacement. That's my opinion and I understand others will disagree.