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How much has your Model S' battery degraded?

tanner

Active Member
Nov 17, 2013
1,169
449
SoCal
My 2013 Tesla P85 (6,500 miles) now has a range of 204 miles at about 85% charge - the loaner I just had (also a P85) had a range of about 220 at 85%, yet it has 2,000+ more miles than my car and it was newer. I thought lithium ion degradation was related to how many times the cells were charged / discharged, not their age? The loaner has clearly been charged/discharged more.

So my question to you is this: what's your range at 85-90% (or even 100%) and hold old is your Model S?

ps will report back when I charge my car to 100% tonight, but based on my calculations, my car should only have 240 miles max range; it was over 260 when it was brand new.
 

mknox

Well-Known Member
Aug 7, 2012
10,103
1,894
Toronto, ON
S85 Delivered March 2013 with a little over 54,000 miles currently.

90% - 216 Rated Miles, 244 Ideal Miles
100% - 242 Rated Miles (did not note Ideal Miles at last 100% charge).

I've only charged to 100% probably less than 10 times since new. Normally charge to between 70 and 90%.
 

tanner

Active Member
Nov 17, 2013
1,169
449
SoCal
VIN 49xx. Received Feb 16, 2013. 13,xxx miles. 90% charge is about 225. Topped off: 250...about.


Really? Your car is both older than mine and has more miles, I wonder why? What's your charge situation like, do you leave it plugged in 24/7 (unless you're driving), like Tesla recommends?

- - - Updated - - -

S85 Delivered March 2013 with a little over 54,000 miles currently.

90% - 216 Rated Miles, 244 Ideal Miles
100% - 242 Rated Miles (did not note Ideal Miles at last 100% charge).

I've only charged to 100% probably less than 10 times since new. Normally charge to between 70 and 90%.

Yours seems pretty close to mine, yet you have more than 8x the number of miles (I, like you, have only charged to 100% a handful of times). What's your routine charge situation like?
 
Really? Your car is both older than mine and has more miles, I wonder why? What's your charge situation like, do you leave it plugged in 24/7 (unless you're driving), like Tesla recommends?

It's plugged overnight only. I have kept it between 80-90 charged. Only topped off about a dozen times in the past 2.5 years. During the day, it sits unplugged for 12+ hours. Sometimes in freezing weather. I have no other options. I drive about 30 miles daily, mostly highway now.

I'm disappointed in the loss given the low mileage of the car. I had Tesla look at it, and they said the battery was fine.
 

yobigd20

Well-Known Member
Oct 28, 2012
5,929
540
Skaneateles, NY
I thought lithium ion degradation was related to how many times the cells were charged / discharged, not their age?

I think for you're "typical lithium ion battery" this statement may be more accurate, but when it comes to Tesla's advanced thermal management and charging algorithms and built-in protection mechanisms that statement does not apply at all. I think one industry expect who has in depth knowledge of Tesla's batteries showed that the number of cycles here was really irrelevant and that in theory Tesla's batteries could last many decades.
 

deonb

Active Member
Mar 4, 2013
4,061
4,362
Redmond, WA
P85 Feb 2013 here. 25000 miles

90% at 231 miles
100% at 258 miles... and it runs 5.5 miles initially at 400wh/m before ticking down to 257

You have to do a 100% charge, then run it down to close to 0, then do a 100% charge again, otherwise the displayed range is meaningless.
 

tanner

Active Member
Nov 17, 2013
1,169
449
SoCal
I think for you're "typical lithium ion battery" this statement may be more accurate, but when it comes to Tesla's advanced thermal management and charging algorithms and built-in protection mechanisms that statement does not apply at all. I think one industry expect who has in depth knowledge of Tesla's batteries showed that the number of cycles here was really irrelevant and that in theory Tesla's batteries could last many decades.

Then riddle me this, why has mine decayed so much? :O I do EVERYTHING Tesla says... Leave it plugged in when you're not driving, only charge to 90% (tops) unless you absolutely need the extra 100% range, etc.... I even usually charge it to only 60%.

- - - Updated - - -

P85 Feb 2013 here. 25000 miles

90% at 231 miles
100% at 258 miles... and it runs 5.5 miles initially at 400wh/m before ticking down to 257

You have to do a 100% charge, then run it down to close to 0, then do a 100% charge again, otherwise the displayed range is meaningless.

Wait, really, does that recalibrate it? Where did you see that?
 
2013 P85+ 30k miles, charged at the Superchargers quite a bit.

90% at 230 miles
100% at 258 miles

I recently got a loaner battery while mine is being worked on for unknown reason and that get 224 miles at 90% and 255 (if I remember correctly) at 100%.

I have no complaints so far, at first I was experiencing severe loss in the first few months when my rated 90% dropped to 224 miles from 236, but after few 100% charges, it went back to 230-232, where it is now for my battery pack. When I get it back in a month or so from Tesla, I'll report again.
 

yobigd20

Well-Known Member
Oct 28, 2012
5,929
540
Skaneateles, NY
Then riddle me this, why has mine decayed so much? :O I do EVERYTHING Tesla says... Leave it plugged in when you're not driving, only charge to 90% (tops) unless you absolutely need the extra 100% range, etc.... I even usually charge it to only 60%.

because the battery pack is very unbalanced (aka cells charge voltages are not balanced exactly within modules) and so it's "best guesstimating" your range when in reality the car has no idea what your actual range will be. Unfortunately there is no way to accurately measure lithium ion battery capacity so they are only algorithmic estimates. Without fully depleting your battery to 0 and then full charging it to try and force balanced cells there is just no way for the computer to accurately know what your exact capacity is or range will be (and even this is not 100% accurate but it can help correct it a little bit, also its impossible to fully deplete the pack anyway since the battery management system has a built in minimum buffer after it shuts down to prevent you from harming your battery) . It can only do a best guess estimate.
 

tanner

Active Member
Nov 17, 2013
1,169
449
SoCal
because the battery pack is very unbalanced (aka cells charge voltages are not balanced exactly within modules) and so it's "best guesstimating" your range when in reality the car has no idea what your actual range will be. Unfortunately there is no way to accurately measure lithium ion battery capacity so they are only algorithmic estimates. Without fully depleting your battery to 0 and then full charging it to try and force balanced cells there is just no way for the computer to accurately know what your exact capacity is or range will be (and even this is not 100% accurate but it can help correct it a little bit, also its impossible to fully deplete the pack anyway since the battery management system has a built in buffer to prevent you from harming your battery) . It can only do a best guess estimate.

Intertesting, thank you for the info... How do you get it to exactly 0? Drive it around the block until it's at 1 then back and forth out of the driveway? haha
 

glhs272

Unnamed plug faced villian
Aug 21, 2013
942
831
Burlington, WI
That's exactly what the Tesla rep told me to do though? So is it actual battery decay or is it just estimated range loss that can be recouped by charging to 100%, draining and charging back up?

In my experience it is just calculation issue. Frankly I have been just charging to 90% for well over a year and half now, so I am not sure if the firmware has gotten better at dealing with this. If you have done the charge to 100% then drive to near zero in a single drive then repeated another time or two and it still makes no improvement, then that suggests that the decay is permanent not just a balance/calc issue.
 

tanner

Active Member
Nov 17, 2013
1,169
449
SoCal
In my experience it is just calculation issue. Frankly I have been just charging to 90% for well over a year and half now, so I am not sure if the firmware has gotten better at dealing with this. If you have done the charge to 100% then drive to near zero in a single drive then repeated another time or two and it still makes no improvement, then that suggests that the decay is permanent not just a balance/calc issue.

Ah, it has to be in a single drive? Darn, now I have to find somewhere to go :D

- - - Updated - - -

Get it down to 1 or 2 miles then blast AC in the garage til the car shuts down... :)

Oh, and make sure you are not in Range Mode....

I never am :p lol, but that sounds like it would work well! Thank you for the tip!
 

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