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Prepaid battery replacement

Prepaid battery replacement

Some one crunch the numbers! It throws the whole " you have to spend 40k on a new battery" argument out the window.

DouglasR | 2 December, 2012

I would be very interested to know what it would cost to replace the battery today. I know we've kicked around the number $40k, but what's the basis for that estimate? Labor costs to make the swap should not be too much (compared, for example, to the Roadster). But what if we are wildly off in one direction or the other?

Since you don't really know "z," the current cost of the battery, you might want to consider a confidence interval around your estimate. Say, for example, the average estimate of the current cost of the battery is $40k, but the standard deviation of that estimate is $10k. That means there is something like a 2.2% chance that the battery is $60k or more. If I thought a replacement battery might cost $40 (even if there were only a small chance of that happening, I might be much more willing to purchase insurance against that eventuality.

ChasF | 2 December, 2012

@DouglasR -

I think we can get within reasonable proximity with a rough analysis of the knowns:

Some quick math (7,000 x 18650 cells => 85kWh) says Telsa may be using 3000 - 3200 mAh Li-on cells in it's battery packs.
Using online cost to regular folks like us (and a little interpolation), I would estimate volume pricing to be about $7 per 18650 Li-on cell.
I would assume Tesla can get those at half that cost, or $3.50 per, leading to an estimated cell cost per 85kWh pack at $24,500.
Throw in about $3K for the enclosure with temp control system, another $7K for profit and we are sitting at about $34K per 85kWh battery pack.

The $40K estimate was, I think, based on a Roadster pack from several years ago when it was less mature and much more expensive.
Seems reasonable that we can estimate today's replacement cost for the 85kWh pack at about $34,500

Brian H | 2 December, 2012

dtesla;
+1 Well thunk.

dtesla | 4 December, 2012

Blog (Pro-EV site) on what we have been typing about here.

http://www.plugincars.com/tesla-model-s-replacement-battery-packs-125571...

Brian H | 11 December, 2012

Here's another option; suppose a 40kWh owner prepays an 80kWh battery? I don't see it specified that you must prepay the same size battery as you've got!

Brian H | 11 December, 2012

typo: "... prepays an 85kWh battery?"

stephen.pace | 19 December, 2012

Quick question: does anyone know if the prepaid Roadster battery replacement program allowed you to transfer the battery to A) a future owner or B) to another Roadster if you totaled your current car and bought a new one?

Scenario 1) I sell the Roadster at 7 years, can subsequent owner get the new battery in 1 year?

Scenario 2) I wreck Roadster at 4 years. Insurance buys me a new (used) Roadster close in age and mileage to current Roadster. In 4 years, can I get a replacement battery?

TeslaOwnerBlog | 19 December, 2012

Here are the details of the programs that were available for the Roadster.

http://teslaowner.wordpress.com/2010/03/05/extended-service-options/

I chose to not buy the battery or the extended warranty. I was planning to sell the Roadster and replace it with the Model S, which I am currently in that process. I figured the new owner would not value the extended warranty or battery replacement enough to justify the cost. The Roadster is still under the original warranty so the new buyer has nothing to fear.

In your Scenario 1 for the Roadster, the subsequent owner would get the new battery.

In your Scenario 2 for the Roadster, the battery replacement is tied to the car so it would not be transferred to another Roadster if you totaled the first one.

I think I have the same feelings about the battery replacement for the Model S but will probably get the extended warranty as I plan to keep this car longer.

Superliner | 19 December, 2012

Don't know about anyone else but I don't plan on still driving my "original" M/S eight years from now. By then we "should" have the Model X and Model ?? who knows what else, and what their capabilities will be as far as battery storage / range etc.

In all likelyhood an eight y/o Model S will be like a 5 year old smart phone lol!! almost useless today when compared to the current capabilities of smart phone offerings. Assuming of course, battery technology improves ;-)

stephen.pace | 19 December, 2012

@TeslaOwnerBlog Thanks!

David Trushin | 19 December, 2012

I agree with superliner. Why replace the battery in a car with an 8 year old computer controlling it. I spoke to the Tesla people and they hypothesized a trade in program. They could refurbish a 6 or 8 year old ms with new stuff and you could get a new car. For $$ of course. And it would undoubtedly be more than the future value of the battery plan.

On the formulas above, why do the math when Excel will do it for you. Just chose your favorite rate of return an plug it and 12k into the future value function.

Brian H | 20 December, 2012

@Superliner;
there's a difference between a car and a phone. Moving mass is different from sharing words and pictures. Consider planes; there are 20-yr old planes in regular use, despite huge advances.

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