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.
Come on guys...
http://www.chrysler.com/en/lifetime_powertrain_warranty/faq.html
You forget about the motor warranty...
@tsx_5
I said 10-15% per year in battery performance improvement over next 8 years- twice your quote from a history perspective; It's real simply, if you don't believe that science, then stick with an ICE car; what's the big deal - live your own belief system
@tsx_5
This is indicative of your other claims of fact that are incorrect
That Chrysler Lifetime Powertrain Warranty was a offered in 2007 as a marketing ploy, because it wasn't transferable on sale of the car, so they were just playing a statistical game knowing people don't keep their cars a lifetime. That calculation against increased sales from the marketing- It had nothing to do with the actual cost of replacement of Powertrain's after 8-10 years of design life.
And most importantly, they LOST THAT BET. I t cost them a fortune, so they dropped it 3 years later in 2009-10
http://www.autoblog.com/2009/08/20/report-chrysler-dropping-lifetime-pow...
Nobody else has offered it since on major production basis. Of course some like Mercedes essentially price in a potion of those coverages into the car like Maytag, but the cost is all there; After 8-10 years, ya gotta cough up the $10k-$20k to make it happen (or pay it up front like Tesla's battery program); And It's about the same cost as the battery in the Tesla- but the Tesla doesn't have anything else major to replace over a 20+ year life. And the battery costs are coming down over time- Powertrain costs are not...
some have stated 1.7% per year
http://images.thetruthaboutcars.com/2012/08/Model-S-range-Tables.pdf
& if you search Stanford, Tesla on youtube a TM engineer speaks of the battery.
It's long but interesting.
What if the battery of Model S, particularly 85kWh, will last the lifetime of the car and replacement is not necessary?
kenliles,
Ok -- you got me on the warranty. I haven't bought a new vehicle in 7 - 8 years (and that was for my at the time wife), so I googled and came across the chrysler warranty. Then I failed to do check it, my bad.
I, for one, will think long and hard before replacing the battery, even when it has degraded to 50% of the original range (I have the 85KWH). For me, and I suspect for many others, even in the degraded mode it will serve me very well for about 95% of the driving I do. Unless the replacement cost and terms are very compelling (e.g., 500 miles range that would greatly simplify cross-country travel), I'll probably continue to drive it until battery degradation makes it impractical for even my local trips.
@tsx_5
I've done the same thing myself. Good to keep each other on our toes!
no worries;
From what I understand and electric motor itself does not need maintenance, though I think I've read that this car's transmission still needs oil changes which is still pretty cheap. An ICE will need a lot of maintenance over 8 years. Here are some things that would need to be maintained in an ICE: belts, oil, oil filter, intake filter, spark plugs, spark plug wires, fuel filter, water pump, and radiator coolant fluid. And of course there are other things that would need to be replaced if they break or stop functioning properly like fans, the many sensors and ICE has, fuel injectors, hoses, valves, piston rings, gaskets, and there's more. I think this would add to the advantage of having an electric motor.
Have you guys seen this?
http://industrial.panasonic.com/www-data/pdf2/ACI4000/ACI4000CE17.pdf
Then this indicates only a 30% loss of capacity after ~2500 cycles
http://www.embedded-world.eu/fileadmin/user_upload/pdf/batterie2011/Sonn...
I'm not sure where this line of thinking comes from (eg warranty is 8 years so replace at 8 years or car only serves __% of the intended purpose in 8yrs so I'm going to spend a fortune making it new again)? By that thinking you would scrap any ICE car every time the warranty ran out (eg 4yrs, etc) and buy a new one. Do the TCO on that and you'll be horrified. Similarly a ICE vehicle is not nearly as efficient at 8yrs as an mpg or maintenance matter ($2000/yr to keep a large luxury ICE car in tip-top shape at 8yrs vs $500/yr at inception). The Tesla should be an awesome car from years 8-12, but not the same awesome it is now but rather awesome to another person (or you) for another application (much like an ICE car). I don't think many here who like shiny new things will be driving an 8-12yr old car, they'll sell it and get the 1000mi range EV that does 0-60 in 2.5 with 10min charging at every corner that will be available by then.
Let's assume that the battery degradation on your Model S after 8 years is unacceptable and you wish to replace the battery but want to keep the car.
Even if the battery capacity and cost is identical in 8 years to what it is today (unlikely, in my view, more likely to have more capacity with less cost, but for the sake of argument lets assume it will cost $12000 to replace the 85kwh battery), and lets assume that you have taken good car of your car and the interior and body are in good condition. You will essentially be getting a nearly new car for the cost of a new battery with another 8 years of use at that capacity! The cost of replacing a battery will certainly be fraction of the cost of buying a whole new car, you keep the depreciation (paying far less in license, registration and insurance fees, and no sales tax on a new car). Another 8 years with no gas and no oil changes, no new transmission, timing belt, water pump, no head gasket, no plugs, no fuel injection, so many less parts to break down and replace. And changing out that battery takes only a few minutes and you are on your way again!
Remember that there are 2 trends operating here:
Gas is getting more expensive (pump price doubled over last 8 years and the 8 years previous).
Batteries are getting cheaper (and better).
Also keep in mind the "black swan" factors. What are the chances of an oil supply disruption over the next decade? What are the chances of a real climate change panic (which might bring about emergency measures like gas tax increases or rationing)?
What is the value of a car that uses no gas under those circumstances?
Notice how after about 1000 cycles, the degradation hits 20% and is slowing, and it takes another 2000 cycles to lose another 10%. That's about ¼ the early rate!
Taking a full cycle as about 200 miles, that means 80% after 200K miles, and another 600K miles to get down to 70%. Total 800K miles. Who will reach it first? >:)
That 200 mi/cycle is a conservative number to accommodate speed, heating, cooling, etc.
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