That's what the battery warranty is for. I was told the warranty is that in 8 years max battery degradation is 30%. In 60KWh model there is also a mileage limit.
-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
That's what the battery warranty is for. I was told the warranty is that in 8 years max battery degradation is 30%. In 60KWh model there is also a mileage limit.
deonb
Active Member
Do you have that in writing somewhere?? So if e.g. yobigd20 drives 800'000 km over the next 8 years, Tesla is warranty'ing that his battery will only degrade by 30%?
That would be some really valuable news!
I just ordered my S85 last week and have not seen the warranty papers. I got the 30% information from Tesla importer in Finland (no Tesla stores yet in Finland). Maybe someone here can confirm the warranty details?
EDIT: I searched the forum and looks like nobody knows exactly what the warranty covers. It covers at least total battery failure but is that it? This discussion should be continued in battery warranty threads:
Warranty of Battery...
Last edited:
The warranty doesn't talk about battery degradation, specifically. Tesla would probably only be obligated to cover that if your battery degrades faster than it should, given the way the battery is treated. But how would you know this is the case? Probably only Tesla has the data to determine this, and they aren't sharing.
Alysashley79
Active Member
The warranty on the manual on my car says "loss of battery or power over time or die to or resulting from battery usage is NOT covered under this battery warranty or the drive unit"
The warranty specifically points out that degradation is not covered. The 30% thing that keeps getting thrown around is just hearsay.
You're right, I missed this part of the warranty:
I think you still might be able to make a warranty claim if the capacity is reduced abnormally, but it will be very hard to make that case. Take care of your battery!
Canuck
Well-Known Member
I was just adding information some people may find helpful and not responding to your post.
I don't agree with the position "to ignore all advice given by anyone unless it is from Tesla corporate directly and in writing." I believe in Rafe Mair's axiom number 1 being: "You make a serious mistake in assuming that people in charge know what the hell they’re doing." To me, this applies to all aspects of life, be it politics, corporations, or whatever else. I think Tesla is learning about batteries as they go alone, as is Nissan. Of course, they know more than most, but they don't know everything and they can be wrong. I agree it's best to follow their advice but sometimes it's difficult to find out what that advice is. So I try to get as much information as I can from various sources and vet it myself. Nissan first told us not to charge to 100% to prolong life, then they changed that position to the point that it is very difficult in recent cars to charge to under 100%.
I found what I posted above to be informative whether or not it actually comes from Tesla and readers can make what they want from it. I also find this information to be informative in understanding how lithium batteries operate, but of course it doesn't come from Tesla...
How to Prolong Lithium-based Batteries - Battery University
OK thanks for the clarification.
I agree that it's possible to infer via observation and experimentation more than what may be explicitly stated.
Tesla is entering the "mainstream" market, and thus has to write at the appropriate level for neophyte owners numbering in the hundreds of thousands.
The roadster had a much smaller user base, was likely comprised of a significantly higher percentage of EV enthusiasts, and were in the "experimental"/ early adopter phase, where publishing whitepapers on BMS strategies and allowing owners to generate log files they could parse on their own wasn't likely to be a support nightmare.
Just because they have to now make the car (and thus the message) idiot-proof for the Model S doesn't mean that there aren't some discoveries about the internals to be made that we might find useful.
So, does anyone have info on when the Model S does its cell ballancing?
1) at the end of the charge, regardless of SOC target?
2) only at the end of a 100% charge?
3) after the vehicle is shut off or put into sleep mode?
4) while driving down the road?
5) some other time?
6) all of the above?
7) none of the above?
GSP
1) at the end of the charge, regardless of SOC target?
2) only at the end of a 100% charge?
3) after the vehicle is shut off or put into sleep mode?
4) while driving down the road?
5) some other time?
6) all of the above?
7) none of the above?
GSP
Todd Burch
14-Year Member
Do I need a citation to state my opinion? I think a citations is needed to show that the car is balancing the battery at 100%, as some here claim. Tesla never said anything to confirm this rumor of balancing at 100% while the car sit for an hour, etc. That is also conjecture not supported by any facts.
- - - Updated - - -
Not true, sorry. Nowhere in the battery warranty does Tesla state an acceptable or unacceptable rate of degradation. In fact, Tesla specifically states in the warranty that degradation is not covered at all. Period.
stopcrazypp
Well-Known Member
I believe it's conjecture supported by the Roadster balancing procedure (explained by Tesla employee here):
http://www.teslamotorsclub.com/show...ter-Battery-Care?p=41995&viewfull=1#post41995
While the Roadster does balance at "Standard Mode" ~87%SOC (it doesn't for "Storage Mode" ~50%SOC), the key characteristic is for the car to "finish" charging (meaning hitting a target SOC) and leaving it plugged in for a period of time after that. The car will still draw power as if it is charging (that power goes to the bleed resistors which we do know exists in the Model S from dissection of the pack), but the SOC will not increase. And for the Model S, the only SOC where people have observed a similar situation occur is leaving it plugged it after it reaches 100% SOC (this is after all the tapering).
I will have to dig a bit further, but I believe there is a post that shows the way Tesla brings an extremely out of balance Roadster pack back into balance relatively quickly is by bringing the pack down to ~20% SOC and then letting it balance at full range charge by leaving it plugged in. Edit, source here:
http://www.teslamotorsclub.com/show...er-Time/page17?p=255689&viewfull=1#post255689
Also, in general, 100% is the best place to balance to in order maximize the capacity of a battery pack. If you want to see the reason why, this book on battery management systems explains the details (starting on page 74):
http://books.google.com/books?id=o-QpFOR0PTcC&q=top+balance#v=onepage&q&f=false
Last edited:
Danal
electricmotorglider.com
Stopcracypp, with great respect, that book is copyright 2010. Lithium chemistry has changed A LOT since then. Specifically, the Panasonic 18650 wasn't yet on the market when this book was written. The first press releases for the version of 18650 chemistry used in Tesla cars were coming out about the time that book went to press. Having said that, all the discussion about "Top" v "Bottom" balancing still hold, to the best of my knowledge, with 18650s. The somewhat more open questions:
- How much "mid" vs "top" balancing is done by the Tesla BMS? Doing some 'mid' balancing allows lower currents in any given BMS, and 'top' balancing can still be performed by the BMS (for all the reasons so well articulated in that book), even after some 'mid' balancing has occurred. I mention "...allows lower currents..." because one thing we know as a physical fact from dissected packs is that the wires and circuit board traces are physically small and could not source/sink very much 'bleed' or 'transfer' current.
- How much 'rest' time is allowed before 'top' balancing, when the car sits plugged in for hours after a range charge? In plainer language, how much of this is actually balancing and how much measuring?
All fun stuff.
Seems to me that a lot of folks make authoritative assertions here that are nothing more than opinion. For instance, the assertion that the car balances at 100% is nothing more than an opinion that is likely to be nothing more than a myth. Nobody ever supported that opinion with one single fact from Tesla. Comparing to Roadster is not a citation and also not valid because a lot has changed since those days. I'm not sure what opinion you hold regarding this subject, but can you cite anything from Tesla to support?
Sure they do in many threads, especially if they are passing on "conventionally accepted (even if not proven) wisdom" when commenting. Myself included.
However, in this specific thread, the OP asked:
Hence you'll notice responses are being qualified as "anecdotal experience", "it's conjecture", or "speculation" & "assumption"
When you come along and make a direct assertion that contradicts the admitted conjecture here in this thread when the OP specifically asked if people are speculating, then you should probably expect people to question what authority provided the info.
Similar threads
