Lost battery efficiency after 5 years

[LargeHamCollider]

Not really. He's talking about the car consuming 100 "rated" kilometers from the display for a real distance of 70 kilometers. That sounds like absolutely normal numbers for a little bit cool temperatures and could be referred to as a form of efficiency, where your consumption is higher, so you're falling short of the efficiency rating values.

The only thing weird I don't get is how he's in Niagara, Ontario, and it took him 5 years to notice this. Getting only 70% of the "rated" values should have been happening every fall/winter.

This is not "battery efficiency," this is total efficiency.

 

[ChadFeldheimer]

Range certainly has as yesterday I drove 151.6 actual kilometres with 211 km being used by the vehicle (and 34.9 kWh).

How many watt hours per km were shown as consumed on this trip? Were there any stops along the 151.6 kilometers driven?

 

[Camera-Cruiser]

The only thing weird I don't get is how he's in Niagara, Ontario, and it took him 5 years to notice this. Getting only 70% of the "rated" values should have been happening every fall/winter.

Funny. The first Tesla tidbit I learned was to use 70% of rated range as my guide to real world driving range, and I’m in Southern California where our definition of cold is nothing like our neighbors to the north. I head out to the wood pile, while the wife breaks out the crock pot when the mercury drops below 70.

 

[lightningrob]

Hi everyone, I have a 2013 Model S P85. My car's battery has been deteriorating over the last year or so.
I now have a 30% deterioration between the what I actually drive and what the Tesla consumes in kilometres.
For example if I drive 70 km the car will use 100 km in charge. I am wondering if others have found this as well with older cars and if there is a solution to this apart from replacing all the batteries. On purchase I was told the batteries should last about 10 years so this is a big disappointment. Hoping Tesla has a solution soon for this. It is not related to temperature or the amount I charge just a general reduction in efficiency. Any suggestions?

Robert,
I found your post when I went to the range thread to report similar findings. I have a 2014 Model S 60 with 31K miles, and the driving range has decreased considerably (over 20%) after 4 years, I'd say mostly in the last year. Originally, I could get about 180 miles on a full charge (less than the rated 206 but still decent). Today, I get barely 140. I don't normally charge to full, but I did it here to get range numbers and report them to TMC.

As you can see in the "full charge" photo, my estimated range was 195 (about 5% less than it used to say). But in the "near empty" photo, after driving 125.8 miles my range is down to 17, for about 143 total. And at the rate at which the remaining range estimate was dropping, I suspect I would have hit empty before 140 miles. Either way, this is about 20-23% degradation after four years with low average mileage. Also, I live in California where it never gets that cold, and I took these measurements during the summer when the car's range is typically optimal. And my driving patterns haven't changed since I got the car.

 

[juliusa]

Many factors affect your wh/mi which determines actual range. Speed, wind, temperature, elevation to name a few. Looks like you have a very healthy battery after 4 years!

 

[Brass Guy]

@Robert I don't think you've specifically mentioned; has your displayed energy use increased or are the kilometers simply dropping faster? The energy use should reflect the rate that range is spent. If your energy use is higher, that's where you need to look. Tire pressures, a floppy undercarriage cover, a dragging brake are a few ideas.

If energy use looks normal, my next suggestion would be to check for range loss while not driving; possibly Pre-Conditioning got turned on or Energy Saving got turned off...

If energy use is normal, and "vampire losses" are minimal, then software must be to blame.

When I was reading the thread early on I thought maybe your range was set to Ideal instead of Rated. (I know the terms are different in Europe, but I think the same for you.) Then you reported your 100% as being less than when new, so I figured that's probably not the issue.

 

[Boatguy]

Definitely two different issues.

My S90D's 100% charge rated miles dropped 7% in the first 20,000 miles, putting me well below the fitted curve of battery degradation.

Consumption is a different issue. My average consumption has been 305Wh/mi. I think the Energy app has the rated line at 300. But I tracked rated miles consumed versus power consumed on road trips and from the first day it's always been 275Wh/RM.

So to summarize:

I started at 294 RM at 100% and now I'm at 274 = 7% battery degradation.
If I drive 100 miles consuming 305Wh/mi I'll use 30,500/275 = 111 rated miles or about 1.11 rated miles for every mile driven.
My 274 rated miles are really good for about 246 miles of real world driving or about 83% of my original purchase 294 miles of rated range.

And in winter it will be worse.

Just for comparison I've owned two BMW i3's and they never exhibited any battery degradation in 30,000 miles. My 2017 i3 which now has 11,000 miles on it is rated for 114miles and consistently gets 120-135. The only time the real world range drops to 114 is with all freeway driving at 75-80mph, or in the middle of northern California winter; cooler than Southern California, but nothing like Scandinavia or the north east. BMW delivers the range they promise through the life of the car.

Tesla, as we've all learned, over promises and under delivers.

 

[David99]

There are two things that need to be looked at separate, otherwise the data is useless.

Capacity loss (degradation) is one thing. Driving 70 km and using 100 km rated range is a whole different issue. Rated range is based on a specific energy consumption per km (or mile). For example on an S 85 the rated energy consumption is 295 Wh/mile or 183 Wh/km.

When you drive and your energy consumption is higher than that, you will of course see more range being used that you have driven. When you say you drove 70 km but your car's range is down 100 km, then it is absolutely essential to know what your consumption was.

Determining how much degradation your battery has is tricky. Comparing rated range when it was new to what it is now (both when charged to 100%) is a good method. This loss of capacity in the battery and thus loss of range is gradual over time. If your loss of range is sudden, that is usually a sign something went wrong in your battery and Tesla needs to look at it. I heard of many cases like that and it usually was a battery module going bad.

If your car suddenly uses more energy, then that's not a degradation problem. Something else is wrong that uses more energy. It could be alignments, bad wheel bearings, bad electrical connection. Some system draining the battery unnecessarily. But you would see that as a higher energy consumption at the end of a trip.

 

[GWord]

Just for comparison I've owned two BMW i3's and they never exhibited any battery degradation in 30,000 miles. My 2017 i3 which now has 11,000 miles on it is rated for 114miles and consistently gets 120-135. The only time the real world range drops to 114 is with all freeway driving at 75-80mph, or in the middle of northern California winter; cooler than Southern California, but nothing like Scandinavia or the north east. BMW delivers the range they promise through the life of the car.

Tesla, as we've all learned, over promises and under delivers.

Re BMW, their design philosophy is to initially reserve some inaccessible capacity to then be gradually doled out to the driver as degradation sets in. It is a bit on an illusion that you have no degradation there. Tesla’s actual battery chemistry is generally superior in terms of actual capacity stability.

So the real question is would you rather have access to the entire capacity and deal with degradation, or would you prefer to have some hidden from you and have at appear as if you have a stable pack? It is psychologically distressing to see something you own diminish. But at least for me personally, having come from a Leaf where we saw 25% degradation, I’ve been conditioned to not break a sweat over sub 10%.

 

[Snerruc]

Could the actual problem be a dragging brake pad or a bearing going bad? This could cause the actual miles used to jump from previous.

 

[Tesomega]

Re BMW, their design philosophy is to initially reserve some inaccessible capacity to then be gradually doled out to the driver as degradation sets in. It is a bit on an illusion that you have no degradation there. Tesla’s actual battery chemistry is generally superior in terms of actual capacity stability.

When talking in %, everything looks very small. However when you look at the kWh that has magically vanished it begs to ask the question, why do you publish the range that you cannot even get in the first 1-2 years of owning the car?

for. eg: I have a 100 D, Expected Rated Range (when charged to 100%) should be 335; However, with 16k miles and 13 months of usage this has come to 309 miles, that's approx 8 kWh of capacity loss. There is not a single official document form Tesla as to explain what is to be expected range in the first 4 years of ownership or what is the available kWh capacity your car currently has.

 

[juliusa]

There is not a single official document form Tesla as to explain what is to be expected range in the first 4 years of ownership or what is the available kWh capacity your car currently has.

Thank goodness for forums and the internet! This has been widely discussed and actual data shared for many years.

 

[GWord]

When talking in %, everything looks very small. However when you look at the kWh that has magically vanished it begs to ask the question, why do you publish the range that you cannot even get in the first 1-2 years of owning the car?

for. eg: I have a 100 D, Expected Rated Range (when charged to 100%) should be 335; However, with 16k miles and 13 months of usage this has come to 309 miles, that's approx 8 kWh of capacity loss. There is not a single official document form Tesla as to explain what is to be expected range in the first 4 years of ownership or what is the available kWh capacity your car currently has.

I think we're all for accuracy and management of expectations when it comes to range advertising, but you can't get around the properties of the chemistry. Battery degradation is directly related to the environment and conditions in which it is presented with. If an owner routinely parks the car with 5% for weeks at a time, it's going to degrade considerably more than someone who charges every day. So what do you want Tesla (or any other manufacturer) to tell you is the official "degraded" range? The reality is that the only sure fire number everyone experiences together, at the same time, is the day 0, new pack capacity. The only real alternative to reporting design capacity is for a manufacturer to hide some capacity from you and dole it out to mask degradation. For me, I don't need the psychological crutch if degradation is within my managed expectations. I'd rather be able to use the extra capacity while I have it.

 

[Tesomega]

I think we're all for accuracy and management of expectations when it comes to range advertising, but you can't get around the properties of the chemistry. Battery degradation is directly related to the environment and conditions in which it is presented with. If an owner routinely parks the car with 5% for weeks at a time, it's going to degrade considerably more than someone who charges every day. So what do you want Tesla (or any other manufacturer) to tell you is the official "degraded" range? The reality is that the only sure fire number everyone experiences together, at the same time, is the day 0, new pack capacity. The only real alternative to reporting design capacity is for a manufacturer to hide some capacity from you and dole it out to mask degradation. For me, I don't need the psychological crutch if degradation is within my managed expectations. I'd rather be able to use the extra capacity while I have it.

Yes, for me, I want Tesla to tell my battery health and current capacity used for its calculation in kW. So, that I can monitor what is working and what is not working for my car and conditions I operate under.

 

[Oldschool496]

So from what I can tell the battery capacity has decreased slightly and maybe slightly more than expected for the milage of the vehicle. Range certainly has as yesterday I drove 151.6 actual kilometres with 211 km being used by the vehicle (and 34.9 kWh).
Thought that meant the efficiency of the batteries to function effectively was decreased.
Perhaps there is another term or maybe it is just a range problem.

Range is dependent on so many things, its very hard to determine from writing here by you, what is happening. You know what is happening though. Certainly in your 5 years with the car your style of driving has evolved. Its very hard to define battery condition, charge capacity and other terms being the same thing.

Last weekend I charged to 226 miles of range or 87% from a Supercharger 72 degree F. My car is 2.5 years old AP-1 and really only fully charges to 245 and has been that way for 2 years. I consider 5.4% degradation normal and holding.

I traveled 160 miles, in the middle of my travel I passed another Model S and she followed me for some distance and then I let her have the lead. We were going 80-85 miles per hour on many stretches 93-100 only to be held back by traffic here and there. I arrive back at my destination with 11% or 29 miles I think left of range. I drive a 75D. It was a spirited drive in my opinion. She undoubtedly must of had to stop again soon, as she was driving a 60 and carried on after I got off the highway.


Not a normal drive for me and used a lot more energy then I normally would on that leg. Funny thing is though not that much more for all that extra speed and up and down. I usually move along at 77mph on autopilot letting the car do its thing.

SO its all in what your doing, fast pace, slow, up and down, and the condition (weather, rain, snow, cold, hot etc) that you are doing them in and things we all forget is the condition good or bad of our motors and controllers-the big unknown in this huge equation. This of course assuming all other mechanical systems, tires and bearings and other are normal and functioning properly.

Your car and battery to me sound all normal, along with your distance you drove in Km and energy you consumed for that drive. Only you know what you are doing and the conditions in which you are doing them.

 

[GWord]

Yes, for me, I want Tesla to tell my battery health and current capacity used for its calculation in kW. So, that I can monitor what is working and what is not working for my car and conditions I operate under.

You actually sort of have that today; the rated range value is based on a fixed wh/mi(km) number for your vehicle configuration. You can estimate that number by looking at the energy graph display where it is plotted as a straight line. Multiply your 100% rated range by the fixed wh/mi and then divide by 1000 to get what your car is estimating as your working capacity in kWh.

Example: My car is showing my 100% rated range as 306mi based on a 314wh/mi fixed efficiency value. 306*314/1000 = 96.1kWh

Caveat: it is an engineering challenge to estimate total battery pack capacity without an actual 0 to 100% charge now and again. So the car sometimes gets off on its estimation and it looks like the pack has degraded when in reality the algorithm has drifted a bit. This is especially prevalent in cars that spend much of their time at partial states of charge.

 

[sorka]

The term "battery efficiency" is being used incorrectly by the OP. Battery efficiency has not decreased by anything near 30%, battery capacity may have, range may have, but "battery efficiency" most certainly has not. Nor has total vehicle efficiency.

Only half way through the thread but you can't assume either from the OPs statement. If he's just getting less range than what it predicts he will have, his problem is most likely less efficient use and NOT degradation.

To the OP, does the kwh used since last charge divided by your total new kwh capacity (about 78 KWH) equal the percent used + about 3%?

If so, then the issue is efficiency and not degradation.

 

[Troy]

OP's problem could be a module failure. OP said his Model S 85 displayed 400 km (249 mi) at 100% when new. A new Model S 85 is supposed to display 427 km (265 mi) in North America. Tesla cars in Canada and US use the EPA rated range system. There is no difference except the units but you can switch between units in the settings menu. Canada and US range numbers are exactly the same when you switch the units.

Efficiency is a different topic and is not directly related to the issue here. There are 3 important data points here:

1. Rated range at 100% when new
2. Rated range at 100% now
3. Mileage

If OP's car displayed 427 km (265 mi) when new instead of 400 km (249 mi), the most likely problem would be a balancing issue. However, there was already 27/427= 6.3% range loss if OP's 400 km number is correct. The 85 kWh pack has 16 modules. If one of them were to fail, you would lose 1/16= 6.25%.

Another possibility is that OP never actually charged to 100% when new. Maybe he wanted to protect the battery. If OP was also watching videos by Bjorn, he might have assumed that the car would display 400 km at 100% without actually trying it. A few years ago Bjorn had a P85 in Norway. Tesla cars display different range numbers in Europe. Canada and US are one region and the rest of the world is a different region in terms of range systems Tesla uses. Coincidentally, the S85 in Europe displays 400 km at 100% when new.

I'm not sure whether the module failure theory or watching Bjorn videos theory is more likely but 400 km at 100% when new is definitely wrong for S85 in Canada.

So I charged to 100% and got 385 km. It was charging to 400 km when it was brand new. I have driven just over 100,000 km

 

[LargeHamCollider]

Only half way through the thread but you can't assume either from the OPs statement. If he's just getting less range than what it predicts he will have, his problem is most likely less efficient use and NOT degradation.

To the OP, does the kwh used since last charge divided by your total new kwh capacity (about 78 KWH) equal the percent used + about 3%?

If so, then the issue is efficiency and not degradation.

Vehicle efficiency is not the same thing as Battery efficiency. Those terms mean different things, the OP is confusing them.