Lost battery efficiency after 5 years

[Robert]

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?

 

[davidc18]

bring it into tesla and have them check the health of the battery. They don't define what "normal" degradation is on the Model S packs. At 30% (when verified) should net you a new battery.

 

[JohnSnowNW]

I'm a bit confused by your comment. Is the car using more energy, as in your wh/m is higher? Or is it that your range drops quickly regardless of energy being consumed?

 

[Robert]

Yes there is a disconnect between the kilometres driven and the kilometres consumed by the vehicle to drive those kilometres.
There used to be battery efficiency such that the amount driven would be almost identical to the amount of kilometres
used by the vehicle to reach that distance. So for example this week I had to travel 170 km so I had to make sure that my car
has been charged to at least 225 kilometres or I would have run out of power. Does that make sense?
I'm assuming it is battery degradation after 5 ½ years.

 

[Robert]

Thanks. I will be getting into Tesla service in November

 

[GreenT]

Interesting. I too have a 2013. 87k. And I recently full charged it and was happy to see 235 miles, when back in 2013 I saw 260m.
I didn't think to see what it actually drained.
I drove 100 miles that morning and I think it might have been 10% more than anticipated but didn't note it.
Rats.

 

[GWord]

Don't forget that it is getting colder out and that drastically increases your consumption versus rated range due to several factors.

 

[Robert]

Yes I may see further deterioration with the colder weather approaching I will have to watch close.
In the past this has been quite minimal for me which is amazing when you are using a vehicle at -20 C
I am seeing two decreases. One is the overall amount that it charges compared to what it did 5.5 years ago. This is relatively minimal.
The other is the disconnect between km actually travelled and km consumed by the vehicle.

Keep an eye on these numbers. Let me know what you find.

 

[animorph]

Battery degradation is normally when the battery meter shows fewer rated miles than it used to when charged to the same percent. That doesn't seem to be the complaint here. And 30% degradation would be shocking.

You might keep an eye on the battery meter and see if it is jumping lower or draining faster at certain states of charge while driving at a constant speed. There could be a measurement/estimation problem.

The description is a loss of efficiency, Wh/km. Absolutely a cold weather problem (we see these posts every winter, and 30% would be typical), or elevation change, or high speed, or hot-foot driving style, or whatever. I have never read of a loss of efficiency like this as a result of some problem with the car itself. None of the trip planners have a specific calibration for degraded efficiency beyond those mentioned.

I'd be very careful to document what you are seeing, with some evidence that it is not just cold weather, before going to the Service Center. Without that documentation I'm sure they'd just blame the cold weather.

 

[Troy]

@Robert, what is your rated range at 100% charge?

The way you are trying to measure degradation is not a good method because conditions will affect efficiency. For a moment let's assume you are driving a brand new Tesla that was delivered today and everything is in perfect condition. If you change the tire pressure, if there is headwind, if there is an elevation increase, if your speed is too high etc. you will consume more energy. In a scenario like this, you might consume 100 km rated range to drive 70 km even with a brand new battery.

However, conditions don't affect your rated range at 100%. Therefore the only thing you should care about is the rated range at 100% charge. For example, if rated range was 425 km at 100% when the car was new, and it's now 404, that means, you have 404/425= 95% capacity left. I recommend measuring your capacity like this and then comparing it to the chart below that shows the average battery capacity based on mileage.

The same chart in miles instead of km can be found here.

In addition, be aware that the range numbers for the Model S and X are over advertised in North America. For example, the Model S 85 in Canada displays 425 km at 100% when new. That was the range Tesla advertised (source). However, the same car displays 400km at 100% in Europe which is more accurate. Therefore your problem is also related to the over-advertisement.

The S85 should have been advertised at 244 mi (393 km) instead of 265 mi (427 km). Model 3 does not have this problem. Model 3's range numbers are under advertised. The new Model 3 MR has more range than the Model S 85. For more details, see the range tables here. I recommend considering switching to a Model 3 MR or LRD.

 

[Gwgan]

rated range was 425 km at 100% when the car was new, and it's now 404, that means, you have 404/425= 95% capacity left.

Not exactly, as Bjorn has demonstrated with his road tests, because the rated distance may be innacurate as the BMS calibration may be off (and usually not in your favor). The rated distance is a good approximation and the graphs can give you an idea about when to worry. Do you [the OP] occasionally discharge to low and recharge to high in the usual course of driving? If not you may want to try that once to see if it improves calibration. Be careful not to run the battery down much lower once power is limited do not leave the battery at 100%.

 

[SDRick]

As Troy said, you need your rated range at 100%. Also, what is your average watts per mile and lifetime wpm?

My lifetime is 346 (rated is 310) and has been consistent for over two years.

 

[Electric700]

Robert, have you tried charging to 100% and then driving within 15 minutes after the charging session completes (so that your car doesn't stay at 100% for too long)? This will balance the battery, though with the latest software update the process may now be done at other charge states as well.

 

[LargeHamCollider]

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.

 

[Robert]

Wow great insight by all. So No I do not leave it at 100% charge all the time. I usually charge to 80%. Cold weather is not a factor yet as it is not cold yet and I have been watching this slowly change over the last year or so.

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 so, as per Troys chart, I should have just under a 95% remaining range or a 6 to 7% reduction.

The average watts per Km are 225 for this year and 226 watts per Km for lifetime. Not sure if this is good or bad but it certainly is consistent.

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.

Thanks everyone.

 

[juliusa]

Looks normal to me.

 

[Troy]

So I charged to 100% and got 385 km. It was charging to 400 km when it was brand new.

Hi, Robert. Are you sure it wasn't 425 km when new? Here is a screenshot from Tesla's website. It shows 425 km for the Model S 85 which had the same range. Also, here is an article from 2014 that mentions 425 km range for the Model S P85. Interestingly, S85 and P85 cars in Europe display 400 km because Tesla uses a different range system there. Maybe you saw a Bjorn video and it confused you. Bjorn also had a P85 and his was displaying 400 km when new like all S85 and P85's in Europe but Canada uses the EPA rating system together with the US. Anyway, you should be able to verify what the range was when knew regardless of what I say because there must be plenty of S85 and P85 owners in Canada. I just wanted to point out that it's possible that you might be misremembering the range. By the way, in case you find this interesting, check out my range table here. It includes the range numbers for the new Model 3 MR.

 

[mswlogo]

Wow great insight by all. So No I do not leave it at 100% charge all the time. I usually charge to 80%. Cold weather is not a factor yet as it is not cold yet and I have been watching this slowly change over the last year or so.

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 so, as per Troys chart, I should have just under a 95% remaining range or a 6 to 7% reduction.

The average watts per Km are 225 for this year and 226 watts per Km for lifetime. Not sure if this is good or bad but it certainly is consistent.

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.

Thanks everyone.

Hmm, cold is affecting me and has been for several weeks with the car in an attached garage, and believe you're about 100 miles further north.
Took me about 40 miles on highway for full regen the other night.

 

[mrElbe]

If you are not pre-heating the car and battery then your result is normal in this cold fall weather.

 

[Rocky_H]

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.

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.