Battery Degradation, cause for concern already?

[Figaro]

A little bit of background:

I live in Maryland where we get legit four seasons
I live in an apartment and I do NOT have access to charging at work or at home
I have had the car since June 2019

Here is some information I sent to Tesla recently:
I have under 5,000 miles on the car. In V9 I charged to 86% in the summer and I was getting a capacity of 213 miles. However, when I went to V10 I am now getting 198 miles. Mind you I was getting this 198 miles around the fall time with cooler temperatures. This morning I charged it to 88% and received 203 miles.

From that Tesla Service center contacted me back since I wanted them to look at my battery.
"At this time we are not seeing any concerning results. The battery’s capacity is in line with similar vehicles in the fleet. The High voltage diagnosis revealed no concerning results. It is normal to see some rated range drop in the early days of the vehicle’s life. Coupled with what you mentioned about cold weather driving, I don't see any issue with your battery."

My charging habits are as follows:
Charge to 85% most of the time, however when some superchargers are completely being occupied I tend to charge to 80%
I have NEVER charged to 100% yet
Starting to charge at different levels. I have started charging at 70%, 62%, 50%, and even the lowest was 17%. Does battery degradation happen faster because I am starting charges at different levels? Is this bad charging habits?

Here is the response I received from Tesla:

'We recommend charging to 80-90% then depleting to about 30% before charging again. For some customers charging to 100% does help with the capacity calculation but only in some extreme cases where their charge habits were different than we recommend. Starting at different levels won’t affect capacity but letting it drop to about 30% is what we recommend. We understand this isn’t possible for all customers. Degradation (potentially) affects capacity. Charging habits may affect the calculation and in extreme cases, may affect the capacity but I wouldn’t worry about this in your current situation."

This morning it was the first really cold night in Maryland, wind chill made it feel like 17. I preheat the vehicle for about 10-15 minutes that is suggested. I saw a 10% decrease in battery by time I went into the car! I feel I am losing so much range or is this just literally normal in the winter? Is my battery degrading at a fast rate? Should I even care to preheat the car besides feeling comfortable? I am not a super fast driver, I don't take off like a bullet and usually follow the speed limit.

I have the following things off:
- Sentry Model
- Standby Mode
- Wifi
- Cabin Heat Protection (off for winter only)

I just signed up for TeslaFi last night to track and see what is going on. I want to go on a trip for about 10-14 days but the car will sit at the apartment not charged. Im worried by time I am back the car will just be completely drained. Any suggestions? Should I try for another service appointment or literally just show up and demand them to take a look at my battery.

 

[Paddy3101]

The Model 3 Owner's Manual contradicts this advice from the Service Center,

"About the Battery Model 3 has one of the most sophisticated battery systems in the world. The most important way to preserve the Battery is to LEAVE YOUR VEHICLE PLUGGED IN when you are not using it. This is particularly important if you are not planning to drive Model 3 for several weeks. When plugged in, Model 3 wakes up when needed to automatically maintain a charge level that maximizes the lifetime of the Battery. Note: When left idle and unplugged, your vehicle periodically uses energy from the Battery for system tests and recharging the 12V battery when necessary. There is no advantage to waiting until the Battery’s level is low before charging. In fact, the Battery performs best when charged regularly."

 

[Petrlol]

You're in for a lot of fun with Maryland winters with no charging at home or work...

All I can say is your rated range is going to be all over the place and the first hour or so of driving, especially with heat. It's going to use A LOT of power.

I was out today for an hour in 23 degree weather, about 10 miles total driving around town. Consumption for the hour came 405 wh/mi. I used more than 60% of the power I would have if it was summer.

Now if I would have driven 1+ hour nonstop on a trip it would have evened out to somewhere near 300 mh/mi or only 25% more power than in the summer. This is my second winter with the car, so I know what to expect, and I have no concerns because I charge at home. I can't imagine NE winters without a charger...

 

[Trips]

I believe that they are getting better at estimating range based on your driving habits and climate. Like a gas car they are providing estimates. The 10% loss for 10 to 15 minutes is extreme. Last winter I was losing about 1 mile per 5-10 minutes with the heat blasting. This was pre-sentry mode.

 

[bluesolarflare]

After V10 Tesla messed around with the Rated Range wh/mi calculations so it is showing lower rated range by 13-15 miles depending on model. Your estimated range is a better number to go by.

 

[Occar]

I believe that they are getting better at estimating range based on your driving habits and climate..

No. Unequivocally no. The range displayed is based on two things (and maybe in very cold cases three things). The EPA range rating and what the car believes is the available power in your battery. Your driving habits won't ever measure in to this. When the battery is extremely cold, a section will show as blue, but I don't know off the top of my head if this changes the range it displays. Regardless, no, climate (beyond the cold making the battery appear to have less energy) and driving habits have nothing to do with what it shows. The cold battery thing is different than your claim here that it is adjusting it due to the temperature outside and the extra power used in colder weather.

 

[SMAlset]

Cold weather will zap some of your charge and if your trip is short, even more, since it takes more power to heat your car initially. There are a number of past discussions on this already. In the first year of ownership there will also be a slight decline in SOC that will occur naturally.

I'm pretty sure TeslaFi will eat up some battery especially if you keep checking in on it or check in on your Tesla app in general frequently.

You have company with others not having home charging so you'll probably get more responses from people in your situation who have had their car since 2018. I'm in Calif and we had freezing temps this past winter so saw battery being affect too. First year with the car and most of my driving is local. It wasn't a big problem just keep an eye on where you are at battery-wise to charge when you get to a certain level. While I have an AWD version and more range, I don't charge every night even though I have home charging. I usually charge at home to 90%.

Since you said you only have I guess Supercharging and public/other L2 charging in your area, when you are going to Supercharge, you should have the car Navigate to your closest Supercharger. Doing this will program the car to heat the battery for best charging otherwise you might be going in with a cold battery depending on how far you've driven.

Elon Musk on Twitter

BTW since this is your first winter, if you haven't noticed yet you will have reduced regen braking until the car warms up in cold outdoor temperatures. So use care when you need to brake. You should see an alert pop up about this and there will be a dashed line on your display. From the manual: "A dashed line appears on the energy bar when power available for acceleration or power that can be gained by regenerative braking is being limited." Also read posts on winter care for your door seals, so if your window gets frozen to the seal you don't damage your car.

 

[Tam]

...14 days....

You can guess if you know how much you are draining overnight right now, you'll know if you can make it for 14 days unplugged.

For winter, I would find a plug-in if I could even if that means paying for a garage rental.

Otherwise, do prepare to jump/replace your 12V battery in order to do anything with your car when you come back.

...86% in the summer and I was getting a capacity of 213 miles...

213 / 0.86 = 247.6 miles at 100% setting.

What kind of car do you have that is rated at 247.6 miles at 100% charge?

For reference, you should compare 100% to 100% and not partial charge to partial charge.

....Does battery degradation happen faster because I am starting charges at different levels? Is this bad charging habits?

For good charging habit, please read the instruction from a Service Center receipt:

Service appointment for 12 month old Model 3 for range loss /invoice for out of warranty inspection?

Set your charge at 90% every night.

In theory, a shallow discharge is better than a deep discharge.

So, if you normally charge your car at 90% and you use 5% per day, don't wait for it to go down to 30% or the depth of discharge difference of 60% before you charge it back up.

It's better to charge it back up from 85% to 90% rather than wait for 12 days to do it.

...Should I try for another service appointment or literally just show up and demand them to take a look at my battery.

If I were you, I would be satisfied because Tesla is not obligated to fix the problems until it goes below the warranty of 70% capacity.

 

[skatefriday]

I believe that they are getting better at estimating range based on your driving habits and climate.

People confuse capacity and range all the time.

Capacity is displayed on the main screen and if displaying miles is always a multiplier of rated range and how many kw hours the BMS tells software is in the battery.

Range, based on driving habits, known route, etc. is displayed on the energy consumption page and will vary significantly from the number on the main screen.

Capacity is what most people are looking at next to the speed. And it's buying a car off the lot and driving away with less than the advertised capacity that people are legitimately complaining about. Unfortunately, most Tesla deliveries are such that people don't get to choose their car off a lot and aren't knowledgeable enough about battery health to do the calculation before driving away. My car had 140 miles of capacity in the battery when I drove it off the lot. I later discovered that it was about 2% short of the 240 miles advertised when I charged to 90% and did the math.

Had it in to a service center for a way off center steering wheel (simple toe adjustment) and had them check battery and they said it was quote, "at average for the entire fleet". That's a really unsettling statement. My week old car was at average when compared to all cars on the road. So when my car is two years old where's it going to be?

Disappointing, but I kept the car. Crossing my fingers I retain capacity over time.

 

[TMThree]

The Model 3 Owner's Manual contradicts this advice from the Service Center,

"About the Battery Model 3 has one of the most sophisticated battery systems in the world. The most important way to preserve the Battery is to LEAVE YOUR VEHICLE PLUGGED IN when you are not using it. This is particularly important if you are not planning to drive Model 3 for several weeks. When plugged in, Model 3 wakes up when needed to automatically maintain a charge level that maximizes the lifetime of the Battery. Note: When left idle and unplugged, your vehicle periodically uses energy from the Battery for system tests and recharging the 12V battery when necessary. There is no advantage to waiting until the Battery’s level is low before charging. In fact, the Battery performs best when charged regularly."

Just so you know, lithium batteries lifespan is best when kept at a neutral SoC. That means somewhere in the 45 to 50% range. Keeping it plugged in to maintain a SoC that is above that will not help retain battery life.

Ways to increase battery life:

1. Avoid leaving the battery sitting at a low or high SoC for a long time.
2. Schedule charging so its done just before you drive it. This limits the high SoC duration.
3. Don't expose battery to high temps. Ideally it doesn't see above ~85F, but park in the shade to help when that can't be avoided.
4. Avoid high depth of discharges if possible. If you do a 20% discharge daily vs 60% discharge by charging once every 3 days, the former will allow the battery to likely last twice as long in terms of charge cycles and number of miles the battery allow the car to be driven.

I'm not listing age, which we can't do anything about. But cells degrade over time, and we can't avoid it (Other than keeping the battery pack on ice to slow it)

If you doubt this post, check out the neat charts on battery university:

https://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

The absolute worse thing to do is high SoC + high temps. You can't use blanket statements like "90% is better than 100%" because 90% in 30 degree weather is absolutely less stress than 80% in 95 degree temps.

The items I listed above are general rules of thumb, you obviously can't avoid them all, but knowing what is harmful to a battery is useful for situations when you can avoid them.

 

[TMThree]

Set your charge at 90% every night.

In theory, a shallow discharge is better than a deep discharge.

So, if you normally charge your car at 90% and you use 5% per day, don't wait for it to go down to 30% or the depth of discharge difference of 60% before you charge it back up.

You're half right. Shallow discharge is better. But it would be nonsense for him to charge to 90% daily if he only uses 5% a day.

If he's using 5% a day, he should charge to 50% or 55%. That keeps the cells at neutral, and even in high temps, the cells aren't massively stressed. Charging to 90% and then dropping it down to 85% during the day is maintaining high SoC and subjecting the vehicle to heat during the summer = most stressful scenario for the battery, and one of the fastest ways to degrade their lifespan.

I personally schedule my charge for 6am with a 65% limit daily, and by the time I get home after work I'm at 45%. On weekends I might charge to 80 or 90% if I need to drive further. But for workdays, my car sits at around 55% while I'm in the office, which is close to neutral. Here is my LR RWD capacity after 10,000 miles.

 

[Figaro]

You're in for a lot of fun with Maryland winters with no charging at home or work...

All I can say is your rated range is going to be all over the place and the first hour or so of driving, especially with heat. It's going to use A LOT of power.

I was out today for an hour in 23 degree weather, about 10 miles total driving around town. Consumption for the hour came 405 wh/mi. I used more than 60% of the power I would have if it was summer.

Now if I would have driven 1+ hour nonstop on a trip it would have evened out to somewhere near 300 mh/mi or only 25% more power than in the summer. This is my second winter with the car, so I know what to expect, and I have no concerns because I charge at home. I can't imagine NE winters without a charger...

Good to know. I am dreading this cold winter and such. So far I have been okay but I will say I am very careful of using the car. Im glad this is going to be my only winter without a charger at home. By chance do you always preheat the battery? I heard it was suggested. I usually do for about 5-10 minutes. Thanks for the information

 

[Figaro]

The Model 3 Owner's Manual contradicts this advice from the Service Center,

"About the Battery Model 3 has one of the most sophisticated battery systems in the world. The most important way to preserve the Battery is to LEAVE YOUR VEHICLE PLUGGED IN when you are not using it. This is particularly important if you are not planning to drive Model 3 for several weeks. When plugged in, Model 3 wakes up when needed to automatically maintain a charge level that maximizes the lifetime of the Battery. Note: When left idle and unplugged, your vehicle periodically uses energy from the Battery for system tests and recharging the 12V battery when necessary. There is no advantage to waiting until the Battery’s level is low before charging. In fact, the Battery performs best when charged regularly."

Spoiler alert. I didnt follow this guys information. I hope maybe if I email again I'll have a different tech respond to me. I try not charge when Im at 70% though. Between 30-60% is when I start charging.

 

[Figaro]

After V10 Tesla messed around with the Rated Range wh/mi calculations so it is showing lower rated range by 13-15 miles depending on model. Your estimated range is a better number to go by.

Thanks I been using this more often and its in line what I am expecting.

 

[TMThree]

Spoiler alert. I didnt follow this guys information. I hope maybe if I email again I'll have a different tech respond to me. I try not charge when Im at 70% though. Between 30-60% is when I start charging.

The key part to that text is "There is no advantage to waiting until the Battery’s level is low before charging."

Avoiding charging to let the battery get really low before recharging just subjects it to deep discharging, which is bad for battery life. Just like keeping the battery at high SoC is bad for battery life.