Decreasing P85D range

[MarcG]

I've been keeping track of the Rated Miles over time, software versions, and lifetime mileage since I got my P85D in mid-December.
As I'm rapidly approaching 10,000 miles driven in a little over 3 months later, I figured I'd share the results so far with everyone.

In the chart below, I've plotted the events at which the rated miles that the car showed at 100% or 90% charge decreased from a previous identical charge, with RANGE MODE set to OFF (turning it ON adds 3 miles):

Please note that the initial numbers at 0-3,000 miles have been normalized to account for the differences in range reported at different software versions.

For those who remember, the initial range was stated as 242 miles for 100% charge (this is what my Monroney sticker showed), then it went up to 252 in a subsequent early release, and finally 253 to match the official EPA rating as stated by TM. For some reason though, I did get 254 miles at 100% (and 228 at 90%) before it lost a mile.


Anyway, I've also plotted battery capacity in % terms based on the normalized rated miles of a 100% theoretical capacity:

And finally, for those interested, here are all the data points I have been logging over time and mileage, including software versions:

The numbers in brackets are with RANGE MODE set to ON, and all the other numbers are when it was set to OFF.

It would be interesting to see if there is a trend line that a regression analysis could predict to see where the battery will end up at, say, 50k-100k miles, then compare it to actuals later.

Which reminds me, doesn't TM guarantee the battery will hold 80% of its original capacity after 8 years/120,000 miles? Or is that a CA mandate I'm remembering, by which all EV manufacturers must abide?

 

[sorka]

I think it's been pretty widely reported that there's an initial loss of a few miles in the first 10s of thousands of miles and that it flattens out a lot after that with a much slower degradation. It will be interesting to see if the P85D can match the P85 in degradation at 100K miles.

 

[rlang59]

Which reminds me, doesn't TM guarantee the battery will hold 80% of its original capacity after 8 years/120,000 miles?

No, the warranty specifically excludes degradation.

 

[sorka]

The warranty excludes normal degradation.

This is going to be sticky issue in the future as consumers claim they are not getting the EPA rated miles out of their vehicles by a long shot. If the batteries degrade a few percent every 100K miles, it'll be fine. If however a battery is at 70% after 200K miles (and less than 8 years), there are going to be class actions and I'll be one of the first to sign up if I find myself in that situation.

 

[Zextraterrestrial]

do you run down to 0 mi rated/ 'charge now' or at least really close to the bottom?

 

[rlang59]

The warranty excludes normal degradation.

And Tesla defines what "normal" is and has not given any guidance on what that is pretty much means it is not covered.

 

[sorka]

The reality is, it's unlikely that a pack that degrades to 80% will keep on slowly degrading over time. That pack is going to have problems and will fail shortly.

- - - Updated - - -

And Tesla defines what "normal" is and has not given any guidance on what that is pretty much means it is not covered.

No, it just means that normal is going to be what's argued in a civil class action.

 

[glhs272]

What are your daily charging habits? Do you charge to 90% every time or do you charge sub 90%. In my experience any sub 90% charging causes range calculation to go off (i.e. exaggerated degradation).

 

[rlang59]

No, it just means that normal is going to be what's argued in a civil class action.

Good luck with that.

 

[MarcG]

The warranty excludes normal degradation.

This is going to be sticky issue in the future as consumers claim they are not getting the EPA rated miles out of their vehicles by a long shot. If the batteries degrade a few percent every 100K miles, it'll be fine. If however a battery is at 70% after 200K miles (and less than 8 years), there are going to be class actions and I'll be one of the first to sign up if I find myself in that situation.

I thought that for all EVs sold in California, there was a battery degradation threshold under which the manufacturer had to replace the battery (need to look it up again as I don't remember the exact details..)

do you run down to 0 mi rated/ 'charge now' or at least really close to the bottom?

No I rarely do that, but I also rarely start a charge under 60% SOC.

What are your daily charging habits? Do you charge to 90% every time or do you charge sub 90%. In my experience any sub 90% charging causes range calculation to go off (i.e. exaggerated degradation).

I try to charge to 90% every time I do charge, which is every other day on average. Sometimes I don't have enough time to get to 90% but I get close enough (80+).
As for 100% charges, I only do that a couple of times a month when I plan a long trip somewhere - which has been every other week on average.

 

[sorka]

I thought that for all EVs sold in California, there was a battery degradation threshold under which the manufacturer had to replace the battery (need to look it up again as I don't remember the exact details..)

Not that I'm aware of. Nissan clarified their warranty when issues arose and formally stated a 70% threshold. If this issue comes up in complaints filed against Tesla in the future, consumers will claim that the reduced range is enough that the vehicle cannot perform as it was intended. Getting to the next supercharger site will probably be one of those arguments. Tesla has left themselves wide open by not having this explicitly clarified most likely because if they did, it would likely be rejected by CARB.

California residents will have a lot easier going after Tesla should there be significant degradation. It don't think it will come to that though. If the battery goes down to 70%, it will continue to drop lock a rock after that. Lithium ion batteries work at a very high capacity until they suddenly go bad.

Honestly, of all the things I could be worried about an MS, battery life is not one of them.

 

[bhzmark]

any update on these stats? I'm at 90%=221 for a P85DL w 20k miles. range mode off.

 

[benjiejr]

One more data point... P85DL 90%=222 w 32k miles (range mode off)

 

[sorka]

22K miles 222/224 with range mode off/on.

 

[BrokerDon]

2015 P85D

16k miles 90% = 225/227 with range mode off

 

[joer00]

2014/15 P85D (Production finished 12/31/2014)

40.600 miles, range was down to 215 as I was driving for 3 years without a home charger (had a P85 before). Now since I charge daily on HPWC it slowly climbed up and reached 220 yesterday after a 100 % charge,

 

[NOLA_Mike]

Another data point - 2014 P85D with 35,215 miles. 90% (Range Mode Off) is 221 miles.

 

[MarcG]

Another data point - 2014 P85D with 35,215 miles. 90% (Range Mode Off) is 221 miles.

Wow didn't realize this thread I started was still alive!

Quick update from my end: pretty much like Mike, my 2014 P85D (delivered in mid-Dec '14) has just over 36,000 miles and is getting 220 or 221 miles of rated range at 90% - though I always have range mode set to ON these days.

 

[P85_DA]

2014 P85D 31k miles ...I get 226 range mode on @90%. Daily charging to 90%...supercharge ~4 times a week as commute a lot

 

[Fezzik]

P85DL. my 90 percent at first purchase was 225. Now its 227 @20k miles. Dont ask me how. but that's what it reads now.