Test drove the 70d and 85d

[spottyq]

Tom Saxton's Roadster battery study showed that degradation is more closely related to mileage than time, with an expectation of 80-85% capacity over 100,000 miles. The Model S battery has improved chemistry and should easily beat that.

http://www.pluginamerica.org/surveys/batteries/tesla-roadster/PIA-Roadster-Battery-Study.pdf

Personally I've seen zero degradation on my five year old pack.

That is some awesome data collection and presentation ! Thanks for the link.

Thank you. So then my original estimate may be correct. Not as terrible as it may seem.

Max*, it does indeed appear you were right, that battery degradation is independent of time.
(We can apply the conclusions of the Roadster battery data to the Model S, right ? Same cells, both has a TMS, and same-or-lower C-rate for the Roadster. Something I'm missing ?)

 

[EugeneM]

Is it working now? I met Franz ??? at the Detroit Auto Show a couple years back. Very cool. I also got this cool pic:

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Another reason I'm stretching to get the 85D is that the 70D, after a few years of slight battery degradation (however long this takes), you're looking at around a 200 mile range, which is what the Model 3 is supposed to be. By getting an 85 you insulate yourself slightly from being in that lower tier with the Model 3. I hope this is making sense - not sure I'm clearly saying what I mean.

Personally, I am leasing. I run a business so the tax savings I get from leasing make a lease a good deal for me so I highly doubt it'll degrade that much in 3 years, or for that matter in 5-6 years. You need to remember that the BMS they use is VERY sophisticated and you have to really abuse your battery as in leave it discharged to zero for long periods of time or always charge to 100% to degrade it like this. As the poster below your post said it's a 17% loss and I think they are projecting 60% capacity after 16 years!

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Had to chuckle at your comment. I got the 70D also and seemed plenty fast enough in drives, 5 seconds -0-60 is good for more than most cars out there. I'm coming from a Touareg Hybrid that is around 6.5-7.5 seconds I think, and our X5 seems fast and its like 7 seconds.

But, again - in Chicago, probably like New York. I spend 90% of my time around 20-40 miles per hour. Part of that time is spend dodging pot holes. Sitting in traffic at 0 mph. Then then when you do finally get to go over 30 you have to constantly watch out for the new speed cameras at all parks and all schools or just near them in Chicago. It's "for the children" but man, our thief/crook of a mayor and city just loves the revenue. Our household has already gotten a few in our "slower" cars so will have to watch it in the Model S. Can't wait to get out of the hellhole named Illinois and back to my home state of Texas!

-T

Oh yeah, I drive a '12 X5 myself and it's plenty fast at 7? seconds 0-60. It's a diesel so the torque it generates is over 425 lb.ft.. At low speeds that car moves! but it's nowhere close to the MS and the 70D seemed lightning fast at the speeds I am used to driving.

On a side note I just noticed 3 new speed cameras in my neighborhood yesterday...

 

[kuttakamina]

Okay phew! Thanks for all your inputs, I was a bit worried there.
Last night I measured distances between all charging possibilities on the east coast.
With the exception of deep in PA or WV, and between Charolette and Atlanta, and from DC to Roanoke - every where on the east coast is approachable with superchargers.
.. and once you add chargepoint and chademo to it, then charging/range etc. is a non-issue.

Still leaning towards 70d, but I've changed my color pref. from black to blue

 

[EugeneM]

I was thinking further about this .. and reading on TMC ..

So, we usually charge the car at 80%.
In winters, the range is 70% of rated.
After 8 years, the battery will likely have 80% capacity left.

So 8 years later, in winter, your range would be - 107 miles on 70d and 120 miles on 85d.

Thats like almost Nissan Leaf bad. Am I misreading this?

Yes you are. They guarantee that the capacity will be no less than 80% when in reality I will be surprised if it drops by more than 6-10% and that is after driving 100k miles.

I run a company that manufactures and sells electric bicycles and while the equipment (BMS and cells) we use is a lot less sophisticated the average life of our battery pack can easily add up to years (though we don't advertise it - under promise and over deliver and all of that). These are small packs so they can go from 100% to 0 on a daily basis which is pretty hard on the battery if our customers ride a lot.

I wouldn't worry about degradation for many years.

 

[kuttakamina]

They guarantee that the capacity will be no less than 80% when in reality I will be surprised if it drops by more than 6-10% and that is after driving 100k miles..

.. I could not find any text with "80%" on Tesla's site.

 

[EugeneM]

.. I could not find any text with "80%" on Tesla's site.

It's not but it's the number that seems to come up in studies and is based on the official TM ratings.

Still I deal with batteries used in vehicle applications on a daily basis and my opinion, based on my years of experience in this field, is that they are setting the expectations too low.

 

[P85DBeast]

If I had test drove the 85D before The P85D I probaly would have gotten the 85D instead of spending more than what was in my budget for my MS but to me the 85D and P85D really don't seem like you're losing power if you get the 85D just a 4.4sec 0-60 vs a 3.1sec 0-60 I mean the My P85D is a little to fast for me and the 85D but I just feel like the 70D and 60D are so underpowered.

 

[Cyclone]

Yes it's working. And to degrade the 70D to a rated 200miles, is a 17% degradation. There was a thread somewhere on TMC where someone hit 100k miles and only had an 6% or 8% degradation, IIRC. You'd have to drive a lot of miles to get there...

My 2013 w/ 31k miles gets 239 miles at 90% and 255 miles 95%. That equates to zero degradation from advertised rated range compared to new. Works for me!

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Okay phew! Thanks for all your inputs, I was a bit worried there.
Last night I measured distances between all charging possibilities on the east coast.
With the exception of deep in PA or WV, and between Charolette and Atlanta, and from DC to Roanoke - every where on the east coast is approachable with superchargers.
.. and once you add chargepoint and chademo to it, then charging/range etc. is a non-issue.

Still leaning towards 70d, but I've changed my color pref. from black to blue

In the Southeast subforum, we have a Charlotte <-> Atlanta thread. It is doable. Two weeks ago I met a Tesla Marketing Rep who drove a 70D up from Atlanta -> Charlotte, charged in Charlotte (the store, not the supercharger) while attending the grand opening event, and then drove back to Atlanta. If the 70D can do it (though she has to be watchful of her speed), then any Model S can do it.

 

[Dutchie]

If it is just about the worry of the battery degradation that you will op for the 85 in stead of the 70 I would still buy the 70.. 10K is a lot of money. Put the money away in an investment account and you problem could buy easily a new battery pack as soon as the mileage gets too low for your comfort..

 

[chriSharek]

Another advantage to the 85 over the 70 is the faster SC Time. So, 10k gets you additional 30 miles of range, 0.8 faster 0-60, faster SC time, and additional battery buffer to combat degradation.

 

[0Q991]

Another advantage to the 85 over the 70 is the faster SC Time. So, 10k gets you additional 30 miles of range, 0.8 faster 0-60, faster SC time, and additional battery buffer to combat degradation.

Not sure there's a clear cut answer to this one. We all have different driving patterns, personal utility, comfort level with the budget delta between the 70D and 85D.

For me, I have the same commute every day during the week. Maybe deviate from it 5-10% of the weekdays in a year. No need to supercharge that I can foresee because we have a big family car for the weekends. The daily range of the 70D is 2x my daily commute and I have a 120V plug for free juice at my parking spot at work. No need for the additional (but significant!) performance of the 85D because my commute is through LA traffic at / near rush hour. On the weekends, I have an ICE car to get the heart racing.

My personal analysis for my situation is that the 85D is certainly better in every way than the 70D, but I won't be able to enjoy any of those added benefits. I can, however, enjoy saving the $10k and I can definitely appreciate keeping the Mrs. happy by saving that added amount.

 

[DPDsModelS]

As for the colors, I think the Titanium is a great color. New, so there won't be a ton of other MS's around looking like yours for a while.

Green is definitely best...

You should definitely get green... oh wait, you can't! :tongue:

Assuming a linear extrapolation (though I've read arguments that the battery degradation is non-linear, and the biggest hit is taken early on and it levels out after that), a 20% degradation over 8 years would be 245k miles... you're planning on driving 245k miles in 8 years?

13,500 miles in 5 months = 32,500 miles in 12 months = 260,000 miles in 8 years. So yes.

 

[brucet999]

I was thinking further about this .. and reading on TMC ..

So, we usually charge the car at 80%.
In winters, the range is 70% of rated.
After 8 years, the battery will likely have 80% capacity left.

So 8 years later, in winter, your range would be - 107 miles on 70d and 120 miles on 85d.

Thats like almost Nissan Leaf bad. Am I misreading this?

Here are two links that should give you better information on Tesla battery life expectancy.

A study of Tesla Roadster battery life
Tesla Roadster Battery Life Study: 85 Percent Capacity After 100,000 Miles | PluginCars.com

Dalhousie University discussion on Lion battery longevity and causes of failure. Specifically shows that Tesla chemistry is different from Leaf and intrinsically better.
Why do Li-ion Batteries die ? and how to improve the situation? - YouTube

 

[kuttakamina]

Here are two links that should give you better information on Tesla battery life expectancy.

A study of Tesla Roadster battery life
Tesla Roadster Battery Life Study: 85 Percent Capacity After 100,000 Miles | PluginCars.com

Dalhousie University discussion on Lion battery longevity and causes of failure. Specifically shows that Tesla chemistry is different from Leaf and intrinsically better.
Why do Li-ion Batteries die ? and how to improve the situation? - YouTube

Thanks! This forum, and all you guys (and gals) are awesome!

 

[brianman]

I can, however, enjoy saving the $10k and I can definitely appreciate keeping the Mrs. happy by saving that added amount.

If you can keep her happy for as little as $10k, take the deal.

 

[0Q991]

If you can keep her happy for as little as $10k, take the deal.

Haha. As with most of our spouses I imagine, it's not the actual matter of the $10k--rather, it's that you're "thinking" about it!

 

[chriSharek]

Haha. As with most of our spouses I imagine, it's not the actual matter of the $10k--rather, it's that you're "thinking" about it!

ABSOLUTELY. I certainly didn't mean to come across that the 85D is for everyone and is the end all / be all. Sorry about that. Maybe I was justifying it to myself!

 

[EugeneM]

Another advantage to the 85 over the 70 is the faster SC Time. So, 10k gets you additional 30 miles of range, 0.8 faster 0-60, faster SC time, and additional battery buffer to combat degradation.

It's not faster. 0-80% takes about the same amount of time. That being said 80% is a different number in miles for the 70 and the 85.

The 30 mile advantage is a fact...whether it's important is different for everyone.

The 0.8sec 0-60 difference..well it's definitely there but for me, personally, considering that I live in a place where most streets have a 25mph speed limit, it's not worth 10k.

That being said, to each his own and EVERY MS is great, no matter which one you go with.

 

[0Q991]

ABSOLUTELY. I certainly didn't mean to come across that the 85D is for everyone and is the end all / be all. Sorry about that. Maybe I was justifying it to myself!

No worries--totally understand. I think we've spoken on other threads on this topic. If the Tesla were my 7 day a week car, I would personally choose the 85D also. Best range, second-best performance (which is already nearly BMW M5 level...).

My point was simply that, depending on the specific needs, desires, and circumstances of the individual, the "best" car is determined by different, personal standards.

 

[clarkbariowa]

So here is the problem, especially if this is your first time driving a Tesla, Instant Torque is like nothing you have ever felt. It is hard to judge both cars when they both feel faster than everything you have been in because of instant Torque. That is why so many people can't tell the difference...