Rated Miles Range Decline

[asleshgt]

After reading this thread yesterday, I also called and talked to Tesla technical assistance to get their recommendation on the daily charging limit. When I called and talked to them the 1st time, I clearly explained him that I regularly have been charging my car to 70% every day and noticed a decline in rated miles after the v6.2 upgrade. The rep. recommended me to charge the battery to 90% for my daily usage even after I told him that my daily % consumption is not more than 25%-30%. The reason that he gave me was that the battery life will be prolonged and is good for the battery. Later in the day, I again called them and talked to a different rep. but this time the rep. told me that I can charge anywhere between 50%-90% and it is not a problem and the battery life will still have a prolonged life even with a daily 50% charge. I then mentioned the 2nd rep. about what the 1st rep. had recommended and the 2nd rep. replied that the 1st rep. might have suggested 90% as he did not want me to charge at 50% one day and then accidentally forget to plug the car the next day due to which the car might lose some miles which might end me up with some range anxiety. I don't believe that...I am hoping that the 2nd rep was totally ignorant of pack balancing, etc, but I am not sure.

Finally I charged my car to 90% last night and I had 235 miles rated and 271 miles ideal this morning after the charge. So, looks like my rated miles is in line with the stats (238 miles rated for 90% charge) listed in one of the earlier messages in this thread. From now on, I am going to consistently charge it to 90% and see how it goes. Thanks for all the responses in this thread!

 

[Polly Wog]

So as I mentioned earlier in this thread, I charged to 100% for the first time today. It peaked at 265 miles of rated range, as expected, and continued to charge for about 40 minutes afterward, not adding any additional range (I was charging with a NEMA 10-30, so 24A/240V). The famous "balancing" that is talked about. Next time I charge, I'll see if anything changes - not that I'm expecting it to given that I haven't seen a range decrease over the life of my car.

 

[yobigd20]

Has anyone reported losing as much as 10% in 100K miles? The most I've seen reported so far is 6%.

no, nothing anywhere near that. i'm at 65k miles and my max range loss is still in the single digits

 

[mknox]

So as I mentioned earlier in this thread, I charged to 100% for the first time today. It peaked at 265 miles of rated range, as expected, and continued to charge for about 40 minutes afterward, not adding any additional range (I was charging with a NEMA 10-30, so 24A/240V). The famous "balancing" that is talked about. Next time I charge, I'll see if anything changes - not that I'm expecting it to given that I haven't seen a range decrease over the life of my car.

The last several times I've tried 100%, the car would not finish... even after three or four hours it was saying "1 Minute Remaining" and still pumping 30+ amps.

 

[MarcG]

Besides the occasional long drives when I charge to 100%, I've been charging to 90% about every other day and have kept track of the range reported (by my P85D, and since late January, by VisibleTesla) along with date, odometer reading, and SW version in this Google doc:

Telsa Model S Range - Google Sheets

Note that not all charge events are logged, only ones which are on a new SW version or show a decrease in rated range. Also note that range reported is with RANGE MODE set to OFF, since turning it on adds about 3 rated miles.

It definitely seems that charging to either 90% or 100% has been consistent for me, with a steady decrease of rated range over time (and mileage).

If you're interested in adding your data to this spreadsheet, by all means please go ahead. I also started a thread on this about a month ago:

Decreasing P85D range

 

[taurusking]

The last several times I've tried 100%, the car would not finish... even after three or four hours it was saying "1 Minute Remaining" and still pumping 30+ amps.

Mine did same thing ...once and second time it took 20-30 mins after 99% was completed...I was thinking pack was balancing or something like that...Have you tried calling Tesla....Let me know..please and thanks

 

[Gizmotoy]

I have about 12k on mine and get 229 regularly charging to 90% twice a week or so. Hopefully that's just indicated loss, though, since it's been awhile since I did a 100% charge: maybe 12 months.

 

[mknox]

Mine did same thing ...once and second time it took 20-30 mins after 99% was completed...I was thinking pack was balancing or something like that...Have you tried calling Tesla....Let me know..please and thanks

I asked when it was last in for service. They said that they did something (pulled logs? ran some sort of test? Not sure) and reported back to me that the battery is "fine". Haven't tried a 100% charge since.

 

[David99]

... 2nd rep. replied that the 1st rep. might have suggested 90% as he did not want me to charge at 50% one day and then accidentally forget to plug the car the next day due to which the car might lose some miles which might end me up with some range anxiety. I don't believe that...I am hoping that the 2nd rep was totally ignorant of pack balancing, etc, but I am not sure.

Lithium batteries age more/faster when they are fully charged. The higher the state of charge, the faster they age/degrade. So from a battery health point of view it is better to charge the battery less.
Battery balancing is nothing detrimental to the battery. It just means some modules, over time, end up with a little bit lower charge than others. The Model S has ways to detect that and equal them out. This is not the same as battery aging, it is not permanent. It is a normal thing and the car takes care of it. Not balancing the battery won't do any harm. It just shows up to the user as slightly less range.
BTW, loss of range over time when just partially charging the battery is not always a battery that is out of balance. The capacity is calculated based on data from the battery and a mathematical model. The smaller your daily charge/discharge cycle is, the higher the chances the number are off. Tesla mentioned this. One way to quickly fix this is to use a full cycle (drive down to just a few percent left and charge to 100%). It basically re-calibrates the capacity calculations. Again this is mentioned by Tesla in an email.

So your rep told you the right thing, the lower you charge the battery the better for it's life. But of course be reasonable. It is not a good idea to run the battery down to zero miles all the time. That's also not good for the battery. Just as much as heat isn't good for the battery life. A very aggressive driving style is bad for your battery.

 

[techmaven]

As David99 said, the lower the state of charge within reason, the better it is for your battery. If you only use 25-30% of your battery on a normal basis, occasionally you use more, so charging to say 50% might leave you with too little range to be comfortable. Plus, you then run into the lower side of the battery which you also want to stay away from.

So, using 40% as the target range, that's 60% of the remaining battery, which means 30% on the bottom and 30% on the top. Which means you should charge to 70% on a normal basis. On an emergency basis, you have an extra 40% of the battery's range available and you normally stay out of both the top and the bottom state of charge of the battery.

As for the amount of miles per charge level, I wouldn't even bother caring about it. Your battery will degrade over time. The best thing is to moderate the charge levels and, again within reason, moderate the temperature. Otherwise, use the car. The only way to do an relatively accurate measure of battery capacity is to range charge, then drive down to near zero and then range charge again. Possibly repeat 2 or 3 times. There's no reason to stress your battery in order to satisfy what is essentially a curiosity. Of course, it's your battery, you can do it if you want. Which also means a road trip is a good way to rebalance and find out. That is why some of the most intrepid amongst us that use the full range of the battery with lots of road trips seem to have a better battery degradation stats - but that's mostly because they're batteries are better balanced and they likely actually have more degradation, not less.

 

[AmpedRealtor]

I asked when it was last in for service. They said that they did something (pulled logs? ran some sort of test? Not sure) and reported back to me that the battery is "fine". Haven't tried a 100% charge since.

If I'm not mistaken, service checks the CAC value of the battery. They can access that using their logs and service screens. The CAC number will tell them the health of the battery. Although I've never asked for this number, I've queried my service center a couple of times about the health of my battery and both times they checked the "logs" to determine that the battery was healthy.

 

[mknox]

If I'm not mistaken, service checks the CAC value of the battery. They can access that using their logs and service screens. The CAC number will tell them the health of the battery. Although I've never asked for this number, I've queried my service center a couple of times about the health of my battery and both times they checked the "logs" to determine that the battery was healthy.

One of the things I'd like to see Tesla do is provide some sort of paper report on overall battery health. I think this would be particularly useful when it comes time to sell the car used. Often, people I meet seem very concerned over how well the car's battery holds up over time, and I can see this as being a deterrent when it comes time to sell the car. If I could provide a potential buyer with a Tesla-certified health report, I think that would allay a lot of fears. I'd be willing to pay for them to run whatever tests are required and provide the report.

 

[jerry33]

One of the things I'd like to see Tesla do is provide some sort of paper report on overall battery health. I think this would be particularly useful when it comes time to sell the car used. Often, people I meet seem very concerned over how well the car's battery holds up over time, and I can see this as being a deterrent when it comes time to sell the car. If I could provide a potential buyer with a Tesla-certified health report, I think that would allay a lot of fears. I'd be willing to pay for them to run whatever tests are required and provide the report.

That would be helpful. However, the last time I did a range charge it showed less than 2% using ideal miles. Given that the results are only an estimate, and probably within 5% of actual, that's almost the same as zero. I don't bother with rated range because Tesla has messed with that so much it's likely to not be within 10% of actual. Rated range is great for trip planning, it's not so great to track SOC.

 

[asleshgt]

When I started this thread, I used to charge at 70% daily, but after reading all the replies on your experiences, I upped it to 90% on 04/12/15. Initially, the rated miles for charging to 90% used to be 235 miles and the rated miles has been gradually increasing once every couple of weeks and now it has hit 239 miles (ideal miles is 276). Now I get an idea on how battery pack balancing works. Thanks for all the replies.

Before I implemented my version of the 90% - 70% routine, I was charging only to 65~75% daily. After some months of the consistently lower charge level, my 90% charge would only provide a range of ~226 miles. After reading the other threads on this, and learning about cell balancing, I then switched to the 90% daily charge (when I'm in town) and now I consistently charge to 232 miles rated range at 90%. But it took roughly two weeks of daily charging to 90% to move from 226 to 232.

 

[AmpedRealtor]

I recently drove down to 1 mile of remaining range. I did not receive the "charge now" warning indicator. Does that bode well for there being additional miles below zero? I'm curious, because at 100% charge the car shows 256 rated miles. I'm hopeful that my battery/range is actually in better shape if I wasn't told to "charge now" at 1 mile of remaining range.

 

[Chris TX]

One of the best ways I've found is to balance the pack is to charge it up to 90% at 30-40 amps, then crank it down to 5A for the remaining 10%. After 27k miles, I've gone from 264 miles new to ~262 after I do that. I bet if I did that a few times in a row it would get back up to 264 @ 100%

 

[UberEV1]

When I started this thread, I used to charge at 70% daily, but after reading all the replies on your experiences, I upped it to 90% on 04/12/15. Initially, the rated miles for charging to 90% used to be 235 miles and the rated miles has been gradually increasing once every couple of weeks and now it has hit 239 miles (ideal miles is 276). Now I get an idea on how battery pack balancing works. Thanks for all the replies.

At least our cars are behaving consistently! :smile:

Since I posted my reply to you, my 90% moved up a bit to 235 and my 100% is 261. Not proof the battery is better, but at least not measuring worse.

 

[steilkurve]

Curious, does changing tires from 19 to 21s affect how the car calculates rated range? Asking because I recently installed turbine 21s on my new P85D, about a month into ownership. At that point, I also started charging at 70% instead of 90. Ever since, I have seen a rated range reduction. So, would that be the 3% range loss from the 21s, the 70% debalancing the batteries or just plain degradation?

 

[jerry33]

Curious, does changing tires from 19 to 21s affect how the car calculates rated range? Asking because I recently installed turbine 21s on my new P85D, about a month into ownership. At that point, I also started charging at 70% instead of 90. Ever since, I have seen a rated range reduction. So, would that be the 3% range loss from the 21s, the 70% debalancing the batteries or just plain degradation?

The 19" and 21" tires have almost exactly the same RPM, so that isn't going to materially change the number.

Rated Range is a very poor way to see any degradation because Tesla has changed the algorithm several times so the number can be up or down from firmware version to version. Use Ideal instead. They don't appear to mess with that.

 

[steilkurve]

The 19" and 21" tires have almost exactly the same RPM, so that isn't going to materially change the number.

Rated Range is a very poor way to see any degradation because Tesla has changed the algorithm several times so the number can be up or down from firmware version to version. Use Ideal instead. They don't appear to mess with that.

I get they have similar RPMs but the 21s are way stickier. Wouldn't that mess with the range? And there's hasn't been any software update since I noticed so I'm not sure it would be the algorithms altering range.