# Forums

## Real Long Term Cost vs. Battery life

let me start by saying two things:

a) I am very very excited to received my Tesla Model S
b) despite the questions below - I have placed my own money on this car…

Question and thoughts center around the longevity of the battery (a question no one can answer) and cost of replacement

1. we know the cost to replace an 85 kwh battery is ~\$12,000
2. we know the warranty is 8 years/unlimited mileage
3. we know batteries maximum charge degrade over time
4. eventually it will be worth while to replace the battery to get back to the vehicle's original capabilities

therefore I believe we have the consider the cost of the battery replacement in the annual cost to "fuel" the vehicle and if you do this the cost to run the car per-mile vs. an ICE car by tesla's own numbers is not very favorable

Assumptions: 15,000 miles year, ICE 22 MPG, gas = \$3.80 gallon, kwh's = \$0.11/kwh

by Tesla's own numbers @ http://www.teslamotors.com/goelectric#savings
ICE Car = \$2591 year in fuel cost \$0.17 per-mile in fuel
Model S = \$467 year in fuel cost \$0.03 per-mile in fuel

that is until you figure in the cost of replacing the fuel tank at the end of an 8 year life span (the battery) - for which you have to budget \$1500 year - making the cost of the Tesla's fuel system \$1967/year or \$0.13 per-mile in fuel…

now I know there are other costs the ICE car has - but for purposes of this thought exercise let's focus on the "fuel" system cost and treat the battery as the moral equivalent of the "fuel tank". Which in an ICE car doesn't shrink, or need to be replaced in 8 years.

Even a 16 year replacement is \$750/year in "fuel" cost to the battery…that still seems to be far less of an advantage than most people would initially consider?

Are there estimates of what the maximum charge of an 85 kwh battery will be in 8 years? What % a year will we as customer lose? How much will my fuel tank shrink each year?

I'm thinking I would replace the battery after it loses 20-25% (300 miles - 75 miles of loss = 225 miles of range - time to swap batteries) of it's maximum range, and if that happens in less than 8 years my fuel-system costs now approach the cost of driving an ICE vehicle…

I'm still excited to get my car, and I'm committed to the success of EV's - but I'm still having trouble with the actual economic benefits when the total life cycle cost is considered - in this case the full costs given the battery replacement cost amortized into the car seem to dramatically change the cost curves.

thoughts, comments, if it takes 20 years to lose 10% capacity then we're good, however if it's more like 20% in 6 years I think the battery cost make the car more expensive to drive.

Sudre_ | 15. oktober 2013

WOW. SO a Tesla Model S is in the same category as a Toyota Sienna. I didn't know that.

I agree lets not exaggerate the maintenance costs but PLEASE lets compare like cars to like cars. My parents have always owned Caddy's and the cost to keep them going (after the 50K) is a lot more expensive than a Toyota Sienna. If \$26K is your budget you should not be looking at a Model S.

I will say that my Caddy owning dad was petting my dash and wood trims the other day... heck both my parents ALWAYS want me to drive now when we go places and it's not the Caddy they want me to drive.

I'll agree if you don't own a car for more than 50K miles then maintenance is probable not something to include. Many ICE manufacturers are now including that for at least that range.

I am also not concerned about range but I have an optimistic point of view. I believe range will not be an issue by the time there are so many people driving a MS that the superchargers will be backed up around the whole country. In the future I will happily rent a 3000 mile non-rechargeable battery from my local service center when I take a long trip. Right now, most superchargers have little to no waiting.

jvs11560 is right in a few comments. I still recommend my dad stick with his Caddy for a few more years. They are retired and drive everywhere. Without the fully deployed Superchargers they would be very frustrated.... however I have the reverse concern jvs11560 has. The OTHER car manufacturers are the ones that will be going out of business if they don't get their acts together. How will you get parts for your Caddy then? Your not going to get your 50K maintenance checkups at the dealer when they are bankrupt.

PaceyWhitter | 15. oktober 2013

avanti,

Toyota's maintenance program extends for two years, so you are just bragging that you have abused your car and are lucky that nothing bad has happened? Here is Toyota's recommended maintanence program: (note how many of these items would not need maintenence on an MS)

Toyota recommends checking the power steering fluid level and transmission fluid level as well as changing the engine oil and oil filter every 3,000 miles or 3 months.

At 6 months or 7,500 miles, Toyota recommends you inspect the wiper blades and all hoses under the hood as well as check the battery, engine drive belts, cooling system and front disc brake pads. The tires should also be checked for wear and tear as well as have them rotated. Finally, all maintenance activities from the 3 month or 3,000 mile point should also be performed during the 6 month or 7,500 mile time period.

The Toyota maintenance program suggests that a series of additional checks should be performed annually or every 15,000 miles in conjunction with the 3,000 and 7,500 mile checks. Included in the 15,000 mile, or 12 month, maintenance is an inspection of the brake system, fuel system, suspension, steering components, drive axle boots, and exhaust system. The valve clearances on the Sienna should be adjusted and the air filter should be replaced. In addition, check the rear differential and transaxle lubricant levels.

The 24 month or 30,000 mile maintenance includes replacement of the spark plugs and wires, fuel filter and, if needed, the distributor cap, PCV valve and rotor. The engine idle speed should also be checked and adjusted if necessary. Multiple fluids require changing, including the brake fluid, manual transaxle lubricant and transmission fluid. The interior ventilation filter on the Sienna should may also need changed. All of these items must be performed in addition to all prior maintenance milestone activities.

avanti | 15. oktober 2013

@Sudre:
"WOW. SO a Tesla Model S is in the same category as a Toyota Sienna. I didn't know that."

SIgh. This list is really hard to take sometimes. I will skip the comment on the childish tone of your response.

If I were to purchase this particular Sienna today comparably equipped, it comes out to \$49,570, which is in the ballpark of vehicles that people consider when shopping for a MS. High end Siennas have fit and finish with more in common with Lexus than the Toyota brand. Arguably better executed than the MS. It is sold as a Toyota for obvious brand positioning reasons.

Moreover none of this matters. We have a Lexus, too, and the same statement is true of that. It has lower milage, so I picked the Toyota to underline the point. I can't speak to Cadillac. Are you saying that your father has had a significantly different experience?

[P.S. -- Does anybody know if the TMC list is more civil than this one?]

AmpedRealtor | 15. oktober 2013

I've never in my entire life spent \$3k-\$5k per year in maintenance on any car, and if I did I would probably not own such a vehicle for long.

avanti | 15. oktober 2013

Not that it matters, but just for the record, the contents of PaceyWhitter's message above is an almost total fabrication. This can be confirmed at the following link:

http://www.toyota.com/t3Portal/document/omms/05ToyAllMS_MS0017/pdf/01oms...

(Be sure to read the footnotes). So, for example, the first spark plug change is scheduled at 120,000 miles (which is exactly what I did one).

Unbelievable!

PaceyWhitter | 15. oktober 2013

My bad, I just copy pasted, my point is that that maitenance exists.

Whalensouth | 15. oktober 2013

brilliant, and my point is that maintenance exists, is pricey, time consuming and something you have to think about. go tesla.

jjs | 15. oktober 2013

@Avanti

Didn't take you comments as harsh.

I would have agreed with you 10 years ago. Not now. Much has changed. Although many of the major car manuf. are producing EVs to satisfy the law, not all are. Nissan is producing the LEAF. Other BEVs are being built and are coming to market. Hybrids have been the bridge technology that is getting more acceptance for EVs. The Volt, although not a BEV is another step in that direction.

The proverbial cat is (almost)out of the bag. I say almost because for the cat to be completely out of the bag we need a major car manuf. to build/sell a BEV at a profit. Right now I think the only car manuf. of any kind that is building/selling a BEV at a profit is Tesla.

So I don't completely discount your statement, but I don't believe it is much an issue as it has been. Certainly not enough of a concern for me that would drive either purchasing or investing decisions.

TikiMan | 15. oktober 2013

jvs,

Just go with your gut instincts. However, please do realize, if it wasn't for the US tax payer, the Obama Admin, and \$49.5 BILLION USD, General Motors wouldn't exist today, and neither would the CTS-V (i.e. they are no safer a bet than Tesla is).

leon.gelernter | 15. oktober 2013

Have you smart guys ever considered that in 8 years batteries will be cheaper?

I guess not...

My guess is in 8 years you can have a battery that will be 500 miles when it comes to range and it will cost 12000. -€ .

Lots of progress in the battery field these days and 8 years down the line...not even Elon knows what kind of technology will be standard by then.

jvs11560 | 15. oktober 2013

I'd like to thank everyone for their insight. What impressed me the most is the loyalty everyone seems to have for Tesla.

Currently, I have a 2012 BMW X6 50xi that has twin turbos and a lot of giddy up. My other car is a 2011 Escalade ESV Platinum series. The BMW spends more time at BMW of Oyster Bay then any car that I have ever owned. Although service is free on both vehicles, the Caddy has never been back to the dealer. Not once in 25,000 miles. I use Mobil 1 and change the oil myself. Actually my kids change the oil with me. It's fun and I know what oil is going into the engine. I guess the Model S owners no longer have to worry about this chore...

Since I was so impressed with the enthusiastic writers on this page, I just scheduled a test drive with Tesla. I need to find out, for myself, what is it about this car that brings so many people together.

Tâm | 15. oktober 2013

@Dortor:

It's a long thread so I am not sure any one mentioned Tom Saxton's findings on Roadster and Model S batteries.

May I repost what I did at:

"Roadster electric cars will retain an average of 80- to 85-percent of capacity after 100,000 miles driven"

http://www.pluginamerica.org/press-release/plug-america-research-shows-t...

In case you didn't notice, Model S drivers seem to find excuses to drive more than they used to with their ICE. For less than a year, it's been driven as much as 35,000 miles. The battery retains its capacity quite well at mostly above 250 EPA rated miles (the spec is 265 EPA rated miles with a brand new car.)

More graphs could be found at PlugInAmerica.org:

http://www.pluginamerica.org/surveys/batteries/model-s/index.php

jk2014 | 15. oktober 2013

Does anyone know the official minimum % capacity over 8 year warranty? I.e. If capacity drops to 70% at year 5 , then warranty covers for replacement or refurbishment. Could not find any specifics in the published warranty...

Tâm | 15. oktober 2013

@jk2014

In case you didn't notice, lots of details are left up to Tesla and we just take it by faith.

What kind of craziness that people would put down a deposit for a car that they never test drive and still has no pricing yet?

It happened for Model S in the US, then now in Asia.

And it happens again for Model X.

That's why it's called a "cult."

We get it first then we watch and see how Tesla would iron out the wrinkles as we go.

For your question, no, there has yet been an official battery degradation percentage for a replacement under Model S warranty.

Your guess is just as good as mine.: My guess would be a degradation down to 65% or 172 rated mile capacity before 8 years or 100,000 miles before you would get a replacement under warranty.

That's still decent to drive from San Diego to Los Angeles, CA one way (about 120 miles.), then supercharge and drive back.

However, as the graphs show, most likely your Model S battery will still have 80% capacity or 212 rated miles after running 100,000 miles.

Hey! I am no scientist so don't hold me to it. I am just a Tesla car owner that's all!

Car t man | 16. oktober 2013

For the economics to work out also, Tesla really does need to do something about more costly issues like tire wear and toe/camber/alignment issues
properly since that is one of the issues that can make or break the cost
expectations of a new owner. I am not talking about high performance tires going at 20.000 miles (and even that is quick) but at 10.000ish it is an
expensive cost not many counted in. It is fixable so it really needs to be
done or many (especially not early adopter and avid fans) will be let down.

Other than that, everyone should make their own calculations given their
situations but this really is a spectacular vehicle and the company really
does appear to be making extraordinary effort. Plus, I think it is better
to give money to those trying to improve the planet than to those who have
repeatedly tried to stifle and bury progress like the big auto have done.

Brian H | 16. oktober 2013

TM has said that degradation stimulates a replacement only if it's really a battery fault, and it would be a partial credit, taking mileage into account. So far, it's looking like a very unlikely problem.

Luclyluciano | 16. oktober 2013

@ Car t man.....

Couldn't the owners with the 21 inch rims get themselves new tires with a harder compound? My AMG has 512 ft lbs torque, low profiles tires with Michelin Pilots all seasons an they last me around 35,000 kms around 20, 000 miles.

Then again, I only push it hard occasionally since a tank of gas is \$110 her in Canada.

Luclyluciano | 16. oktober 2013

I know, I am factoring in the gas savings as part of the attractiveness and excitement in justifying the purchase of this car. I am not factoring in the depreciation of the battery. I am blindly trusting Tesla and theses forums.

It appears to me a lot of Buyers are doing the same. It seems to me many buyers have little business buying such an expensive vehicle financially speaking, unless the real cost justifies it for them. Coming from a honda or a Toyota with an average income and buying a vehicle for \$100k plus just seems wrong financially speaking.

Hopefully it works out for them.

p1SL | 17. oktober 2013

Part of the cost discussion should include the soul-sucking experience of pumping gas. Not to mention the "low tank, should I fill tonight before I go home, or leave early in the morning to fill..."
I will trade a little range anxiety on the occasional road trip any day for never having to go to a gas station again.
Except I stopped at one today just to clean the windows. Almost felt guilty. Almost.

Brian H | 17. oktober 2013

Most homes have their own water supply.

p1SL | 18. oktober 2013

I prefer the brown water of a gas station squeegie.

Roberto | 19. oktober 2013

I guess that it all depends on how much you drive. I spend \$500 per month in gas, \$6,000 per year, \$48,000 in 8 years. Verses \$8,600 (82% cheaper than Gas) in 8 years of electric use that's a savings of \$39,400. Tesla cost about \$80,000 - \$39,400 = \$40,600 ( car cost in 8 years).

You take the same analysis and apply it to a Mercedes S550, my car. It cost me close to \$100,000 at the end of 8 years I would have spent 100,000 plus \$48,000 on gas = \$ 148,000, this doesn't take into account all the other thousands and thousands on other issues.

You said the battery cost was \$12,000 and you have to factor in that cost. So, let's factor in the cost and compare. My gas savings in 8 years was \$39,400 and now I am spendings another 12,000 on a battery. However, I just expanded my car life another 8 years. So let's do the math. The car cost me \$80,000 plus 12,000 for the extra battery = \$92,000 - \$39,400 (first 8 yrs saving) - \$39,400 (next 8 years savings) = \$13,200 the cost of my car in 16 years. Verses my S550 will cost me \$196,000 during the same period of time.

Koz | 19. oktober 2013

Assuming the OP's premise of gas vs battery cost only. Not a very meaning comparison IMO, but nonetheless some considerations are missed in analysis.

-Gas at \$3.80 vs electricity at \$0.11 over lifetime ownership assume inflation at parity for both. Bad assumption based on historical pricing and predicted supply/demand

-if \$12k battery cost alocated to first 8 yr period then \$12K should be deducted from the initial cost of the car, otherwise running cost is only \$12k for 16yrs of use

-Assumes \$0 value to the old battery. Given that we are using today's \$ and predictions. The old battery will still have about 68kwh of storage capacity which today's equivalents cost about \$150/kva for standalone applications for good lead acid. Current value for 68KWH of used LiO should be in the \$5k range.

-Assumes same battery for the \$12K repacement. While that price is for an 85kwh replacement size, the logical assumption based on battery development is that a then current battery pack will have more cycle life and less weight.

-Battery costs are going down while gas prices are going up. \$12k is a reasonable assumption for pack replacement cost in 8 years but the rest of comparison is done In today's \$. So either gas price inflation has to be factored or the \$12k in 8 years needs to be brought back to today's \$.

Brian H | 19. oktober 2013

Roberto;
Compare initial cost + 'fuel' for both.
80K + 8600 = 88,600
versus (note spelling)
100 + 48,000 = 148,000

Second 8 yrs:
12,000 + 8,600 = 20,600
versus
0 + 48,000 = 48,000

Assuming no change in electricity and gasoline costs.

16 yr totals:
88,600 + 20,600 = 109,200
versus
148,000 + 48,000 = 196,000

TeslaEV | 19. oktober 2013

It's missing the whole picture. If you isolate just the fuel savings an ICE can be cheaper under normal annual driving distances. It's an apple to oranges comparison. I am getting an S because I only have to go in once a year for maintenance. TIME is what it saves me. I spend 10 hours a year just for oil changes and that doesn't include spark plugs, transmission, brake pads etc. TIME is something I cannot buy back. In total it is a whole day I get back by having an EV just with oil changes. If you put in all the TCO of 8 years for a comparable ice and the MS I am sure it is cheaper.

And most of all with saving TIME I have to refuel the ice car at least once a week, going out of my way, taking 15 minutes out of my day purely to refuel the ice car. The time it will save me in a MS and superior driving experience will make the value of the vehicle far better for the dollars I pay for an ice car.

slickandjake | 19. oktober 2013

I am getting my Model S in December. I cannot justify the cost as a savings in a short time period, but I am making assumptions that over a long time period I will save a lot. I think recent posts here hit it on the head. One assumption I have is: this could be the last car I ever buy. Why do we give up our ICE cars? Some people because they just need a new car every few years, but that's not me I am a utilitarian. Mainly because after 150k or more miles the wear and tear on the multitude of parts in the vehicle make repairing the vehicle not worth it versus buying a new car. So my plan is to take care of the car frame and interior and then the only major cost will be replacing the battery or perhaps other somewhat minor parts. So at the end of the 8 years instead of buying a whole new car I just replace my "engine", i.e. a battery. A battery I am assuming will be cheaper and have greater range. This assumption has some risks. In 8 years an 85 kW lithium ion battery may be obsolete. So will they be able to retrofit whatever the modern battery is to this car? Tesla may be out of business too, so who will service my car? I think of those risks as low, but they are risks. Accepting those risks and assuming things are the same in 8 years as they are today (in actuality I think it will get better), are you telling me that over time you will not save money if you only pay \$12,000 every 8 years for a new battery while saving \$2500/yr in fuel costs? It all depends how long you want this vehicle. And there may be other costs, such as replacing the seats or body work for the exterior for minor dents, but the fuel savings indefinitely will more than make up for it. And if in 8 years I am wrong and my car is obsolete and I have to buy a new one at least I was able to drive a performance vehicle for 8 years for not that much more than a gas guzzling car. And the time I saved on gassing, oil changes, engine repairs, etc. will be more than worth it to me.

So if you are trying to cost justify this vehicle purchase it comes down to this: 1) Are you willing to have this car frame for an indefinite period of time?; 2) Are you willing to take a small risk that in 8 years this car will have a battery for it and a company that will service it?; 3) Are you willing to take care of your frame and interior, or at least be unconcerned for their appearance if you don't want to take care of them?

That's about it. If you an accept those above then you can cost justify it over the course of somewhere in the 10-15 year timeframe depending on circumstances and assumptions.

Roberto | 19. oktober 2013

Above I estimated the cost of the Tesla to be \$13,200 in 16 years, because I got the cost that I saved in gas during the 16 years of use and applied it to the car. Unlike my S550 the cost of the car goes up during the 16 years when you add the fuel cost, \$196,000. Another observation is that you are more likely to keep an electric vehicle as a second car once it's old, because it will be a huge asset if you still can obtain the same gas savings. Unlike gas cars, that leak oil all over your drive way and become less fuel efficient over time. My Tesla arrives in December, I can't wait to test out my theory.

772 | 20. oktober 2013

i doubt the same 85kwh battery will still cost \$12k (in 2013\$) in 8-10 years. cost of technology and batteries especially should fall dramatically... even 3rd party batteries should be available at that point. I'd expect 6-8k in 2013\$\$ at most in 2021 for the same battery, but realistically it will probably only cost about \$2-3k.

772 | 20. oktober 2013

however, the cost of disposing said battery is another issue and cost is uncertain

Brian H | 20. oktober 2013

TM sez its batteries are almost entirely recyclable, and they are certainly reusable for static storage applications.

inverts | 20. oktober 2013

I bought the 85 for the 8 year/unlimited miles battery warranty. I drive about 25k/a, so have a 200K mi warranty. Not bad. With the assumed 3%/a capacity decline (usually cited without any distance!), I can still do my 150 mile commute without re-charging.

The rest: so what? We'll see how the rest of the MS holds up in 8 years. I got rid of my previous car (Prius) after 8 years to get the MS. That was the time when it started to show some problems. Nothing too serious (shocks, sticky gear shifter), but there were signs.

I did get prepaid service for 100K miles (= 4 years for me), mainly for peace of mind. Whether I will get the extended warranty after 100K miles, I'm not sure. Will see how the car holds up. So far so very good :-)

Whether batter replacement on my dime ever becomes an issue is completely open. Either the battery fails before 8 years, then it is a warranty issue. If it fails after 8 years, it depends on whether I expect car to hold up for another 8 years, then even with a better battery of unknown kind. If I don't think it is worth to do the replacement, I'll replace the entire car. Either way, I smile while I drive. Cost? I don't give it a moment's thought.

As most posters mentioned, this purchase is not about penny pinching, but about spoiling yourself rotten. Guilty as charged.

P.S. If you are so tight financially that you wonder whether the MS saves you money in the long run, then the MS is not for you. Stick with the old paradigm; at least you know what you get.

SCCRENDO | 20. oktober 2013

@inverts I do similar mileage to you and share the same philosophy. What is not clear is the price of future batteries. I am not sure the real price is \$12000. It is apparently subsidized and some suggest it may be \$40000. And one hopes it will come down in price as these things usually do. However even if it costs me \$30000 to get a good as new car in 8 years and 200,000 miles it would be worth it.

Brian H | 20. oktober 2013

Had a thought about the batteries; typically, the steepest decline is early on, flattening out to a much slower decline later. But so far, even drivers with the most miles are reporting very little loss of range. So if this is the max decline, the prospects for longevity are very good. I'm sure the boffins at TM monitoring the logs are feeling very pleased with themselves about now.

Bighorn | 20. oktober 2013

@Roberto
You need to reconsider your math, I think.

LEvans | 20. oktober 2013

So just to clarify what is the cost right now to replace a 85kwh battery with a brand new one? Is it \$12,000?

SCCRENDO | 20. oktober 2013

@web srfr I don't believe so. Tesla at one point was offering a \$12000 prepayment plan but that was more like an insurance plan. Rumor has it that it is closer to \$40000. However I'm not sure I've seen anything from Tesla. As we have an 8 year warranty I don't think anyone has had one replaced. If it costs \$10000 dollars more for a 80 vs a 60 I doubt the whole battery costs \$12000.

Luclyluciano | 21. oktober 2013

@sccrendo.....

Rumor has it that it is closer to \$40000.

This is crazy!!! Is this true?

Jolinar | 21. oktober 2013

Real battery cost is not known, but I reccomend to see this links:
Tesla presentation for investors

discussion with JB Straubel about battery cost

So true cost for 85kWh battery is probably somewhere between \$17,000 to \$25,500.

Jolinar | 21. oktober 2013

@Luclyluciano

If I remember correctly that was true for the Roadster, not the Model S. Or at least that was the replacement cost including profit margin.

DallasTXModelS | 21. oktober 2013

I don't consider the battery as fuel cost rather a component of the car itself. Since electricity is the fuel the battery would equate to the gas tank on and ICE vehicle. The cost of electricity is equal to the cost of fuel.

If and when the battery will not take enough charge to perform for a couple of days activities I will replace the 85kwh battery with a new one and to me will have the equivalent of a new Model S. So basically the price of my Model S plus the cost of a new battery divided by 2 equals the cost of my next two cars.

SCCRENDO | 21. oktober 2013

I have the same philosophy as DallasTXModelS. I don't know the true cost and most of my info comes from Tesla haters. The question is whether they have truly got the cost down as low as stated or are the taking into account all the subsidies they get to amortize the actual cost.

Brian H | 21. oktober 2013

Money quote from the interview with Straubel: "By most estimates, the battery for the Model S that I drove should cost between \$42,500 and \$55,250, or half the cost of the car. But Straubel indicated that it is already much lower. “They’re way less than half, actually,” he says. “Less than a quarter in most cases.”"

Roberto | 21. oktober 2013

BigHorn:

What's wrong with my math calculations?

Bighorn | 21. oktober 2013

@Roberto
You were adding the cost of gas to the MB and subtracting the savings from the MS. Can't do both. You need to add the cost of electricity to the price of the MS to find your TCO for an apples to apples comparison. No cake and eat it too math.

Brian H | 21. oktober 2013

Roberto;
That's why I did this simplified breakdown, above, this time with labels:

Compare initial cost + 'fuel' for both.
MS: 80K + 8600 = 88,600
versus (note spelling)
MB: 100K + 48,000 = 148,000
Difference: 59,400

Second 8 yrs:
MS: 12,000 + 8,600 = 20,600
versus
MB: 0 + 48,000 = 48,000
Difference: 27,400

Assuming no change in electricity and gasoline costs.

16 yr totals:
88,600 + 20,600 = 109,200
versus
148,000 + 48,000 = 196,000
Total Difference (in MS' favor): 86,800

nickjhowe | 24. juli 2014

Tom Saxton just uploaded his TMC Connect presentation with the latest battery data:

Tom's conclusion is that charge cycles (total kWh drawn from the pack/pack size) have the most impact on range, and that Chart 10 (Rated Range vs Estimated kWh Used) and chart 11 is the best ways to see that.

The furthest right point is roughly 300 cycles and is still showing c. 250 miles on a range charge (vs 265)

Slide 20 (Expected Capacity at Miles Driven) is really telling - it shows how quickly Nissan Leaf range drops compared to Model S. This is primarily due to lack of thermal management on Leaf packs (slide 22), and the much higher number of cycles due to a much smaller battery.

Great information. So extending some of the graphs, at about 1,000,000 miles, I will still have the range of a new Leaf/i3 and at 1,200,000 miles I will be in Volt/ELR territory. If that holds true, it certainly would provide a great cost/mile number for the MS despite its high initial purchase price.

Now, do I charge to 53.7% or 67.5% or 89.7853% ;)

SCCRENDO | 24. juli 2014

One would need a statistician to look at it but I'm not sure we can draw any statistical significance of the data at this point. There are too few data points above 40000 miles. I would suggest that there is an immediate drop off in the first few thousand miles and then the curve flattens. Also what is not clear is how much of the drop off is software or 'unbalanced battery' related.

MY own experience is not knowing my initial range as I did not range charge and used ideal miles in the beginning. Firmware changes have changed the whole calculus. All I know is that from 6 months and 12000 miles to my present 15 months and 40500 miles I have not seen a change in range. I know this because I submitted my data to Tom and both timepoints. MY present 252 rated/292 ideal miles at max charge indicate to me either a less than 3% early drop-off in range that has not progressed vs no range loss but my other miles being hidden in a below zero buffer or unbalanced cells.

My5bAby | 24. juli 2014

STOP WORRYING ! Prius batteries have gone significantly further than originally imagined. I've heard that even the original batteries still don't need to be replaced after all these years.

Now onto facts NOT rumors.

I drove cross country for Teslive, then down into Mexico (Tijuana) and am on my way up to Canada (Vancouver BC). This is so the next time someone asks me about road trips, I can respond with, "to which contiguous country are you referring".

TODAY, I have 93,500 miles on my car. I did a max charge in order to visit Crater lake in Oregon. Max rated was 248, Ideal 280. (This is without rebalancing) 248/265 = 94% (an apparent 6% loss, however because range is an algorithm the loss is probably significantly less) I took a picture of the dash and will post tomorrow because I'm tired from driving.

Good night and sweat dreams.

P.S. many people saw my car and the odometer at Teslive.

Mathew98 | 25. juli 2014

Only 93K in 19 months? Slacking off a bit, aren't you?

6% loss isn't bad at all considering no balancing has been performed. What percentage do you supercharge and how often do you SC?