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Early 75/75D pack degradation

Thank you for this detailed explanation. As I read the above - I get the impression that "Chipping" and "Mapping" are the same thing. Did I get that right?
Years ago I was aware of something called "blueprinting" an engine to extract a tad more power. Is "Chipping" and "Mapping" the same thing (modernized equivalent of) blueprinting?
Blueprinting is literally making the components to the blueprint I.e the exact design rather than to a tolerance. (E.g. if a piston should weigh 10+/- 0.5 then a normal engine would have pistons weighing e.g. 10.5 10.2 9.8 9.5 and be in tolerance, a blueprinted engine would be 4 x 10 ). Has the advantage of a smoother tighter engine that can take more abuse...
no one has “blueprinted” a motor transmission combination as far as I know.
 

Buster1

Member
Oct 13, 2016
582
276
Ft Worth
Basically. It took us 10 pages to iron that out. ;)

The other point is that their is some pack degradation, it happens. But often there is perceived degradation which is the BMS simply doing calculations, and if you haven’t balanced cells or charged to 100 or discharged to 0...the BMS algorithm wont be accurate.
 
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ran349

Member
Jun 28, 2016
452
307
SoCal
So is the gist of this whole thread not to be dismayed if we see our rated miles drop over time? 80% charge remains 80% regardless of the reduction of rated miles?
No. Over time, 80% represents less rated miles than what 80% represents for a brand new battery. If you have a fully charged 249 rated mile battery, 80% represents 199 miles, and if your battery degrades to 240 rated miles at 100%, then 80% represents 192 rated miles. Setting it to read in percent doesn't change anything, it just masks the degradation.
 
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No. Over time, 80% represents less rated miles than what 80% represents for a brand new battery. If you have a fully charged 249 rated mile battery, 80% represents 199 miles, and if your battery degrades to 240 rated miles at 100%, then 80% represents 192 rated miles. Setting it to read in percent doesn't change anything, it just masks the degradation.

Wow. You must have a way of gazing at the innards of my S75D. Your numbers are spot on for a March 2017 build with almost 16,000 miles. I charge the battery at home to 100% about three times a month. I also supercharge to between 90% to 100% three or four times a month, for the 145 mile drive back home. 100% yields 249 rated miles, 80%, 199 miles.

I hope the rate of degradation decelerates from now.
 
Wow. You must have a way of gazing at the innards of my S75D. Your numbers are spot on for a March 2017 build with almost 16,000 miles. I charge the battery at home to 100% about three times a month. I also supercharge to between 90% to 100% three or four times a month, for the 145 mile drive back home. 100% yields 249 rated miles, 80%, 199 miles.

I hope the rate of degradation decelerates from now.
Did you take into account that winter will quite drastically reduce driving range? I'm pretty sure you will be pleased in summer and concerned again next winter ;)
 

Northern S

New Member
Feb 24, 2018
3
0
Toronto
So, I have been reading through this thread and appreciate all the responses. I have a three month old Model S75 and it has never come close to the advertised 75 KWh or 416 Km (250 miles) capacity. My question is, if we are not supposed to get the mileage or battery capacity advertised when the car is new, how do we know if the battery maintains its capacity as defined in the 8-year warranty?

I appreciate any responses or insights from other owners.

Thanks.
 

JasJ

Member
Jan 26, 2017
423
491
Houston, TX
Probably because you've only driven it in the winter in Toronto.

My nine month old MS 75D was 244 miles at delivery (100% SOC) and is now 245 miles last trip where I went to 100% SOC in the last week..

I least I have not lost miles... seemingly gained a mile, but I never EVER had the rated 259 mile in the 'sales brochure' from day one.

Kind of weird, but I take solace that the initial year's range loss has not further materialized.
 
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Northern S

New Member
Feb 24, 2018
3
0
Toronto
Probably because you've only driven it in the winter in Toronto.
Hi JRP3, yes I agree, driving in the Canadian winter reduces the car’s range. I also understand that all these readings on the battery capacity are estimates of some kind. What I am trying to understand is how does a Tesla owner (or Tesla for that matter) know when the battery has fallen below the capacity threshold covered by the warranty? There doesn’t appear to be any reliable way for an owner to determine what their battery capacity in KWh is. Am I missing something?
 

BerTX

Active Member
Supporting Member
May 2, 2014
3,505
3,653
Texas/Washington
Hi JRP3, yes I agree, driving in the Canadian winter reduces the car’s range. I also understand that all these readings on the battery capacity are estimates of some kind. What I am trying to understand is how does a Tesla owner (or Tesla for that matter) know when the battery has fallen below the capacity threshold covered by the warranty? There doesn’t appear to be any reliable way for an owner to determine what their battery capacity in KWh is. Am I missing something?
You might want to study that warranty again. It is possible the provisions in Canada are different, but for us there is no defined numbers to determine capacity loss limits. I don't think capacity loss is covered specifically, just failure.

I seem unsure -- maybe I should go study MY warranty again... :oops:
 
Did you take into account that winter will quite drastically reduce driving range? I'm pretty sure you will be pleased in summer and concerned again next winter ;)

I commend you for your optimism. Even with our recent “cold snap” where night time temperatures “plunged” to 8 degrees Celsius to 14 degrees Celsius, winters here in Southern California are very mild. Year round, our temperatures average 21 degrees C with maybe a 10 degree C variation on either side.

Could such a minor drop in ambient temperatures really make that much difference? I’d be very happy for you to be right.
 
Well all I can say is that if you look at the numbers entered into the sheet here clearly indicate that if the reading is taking during winter time (whatever that is as you rightly point out) show quite a bit less capacity than if taken in summer time.0000\

Of course, depending on location and thus temp difference between summer and winter this may be more or less pronounced.
 
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Well all I can say is that if you look at the numbers entered into the sheet here clearly indicate that if the reading is taking during winter time (whatever that is as you rightly point out) show quite a bit less capacity than if taken in summer time.0000\

Of course, depending on location and thus temp difference between summer and winter this may be more or less pronounced.

Thank you for the additional comment and the link. Unfortunately for me, I couldn’t open it with my email account. I’ll just wait to see if there’s a rebound in rated range as Spring nears.
 

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