Battery degradation, replacement cost $22.5k. Roadster owners please speak up.

[gg_got_a_tesla]

Fascinating stuff from the CHAdeMo/SAE-QC support thread on the design intent behind the lifetime for the Model S battery packs!

The info below comes from a Tesla engineer group leader named Lars.

Whereas the LEAF battery pack is series-parallel, composed of 96 cell-pairs wired in series, the Tesla arrangement is reversed: parallel-serial. 14 modules, each containing enough cells in series to generate the full voltage of 400V or so, with the 14 modules in parallel. Temperature of each of the 14 modules is tracked and controlled independently.

The design intent, not guarantee, is for the temperature-controlled battery pack to lose no more than 30% capacity over 18 years. Compare that to the disappointing capacity decline being reported for LEAFs after just one year in warm climates.

There will be adapters to allow both the 85 kWh battery, and the 60 kWh battery, if equipped with the Super-Charger option, to charge from CHAdeMo or SAE Quick Chargers. The 40 kWh battery will not have support for DC through the Tesla charging port.

Original post on the My Nissan Leaf forum:
My Nissan Leaf Forum View topic - Tesla Model S

[mulder1231]

The design intent, not guarantee, is for the temperature-controlled battery pack to lose no more than 30% capacity over 18 years.

That's very interesting indeed. You could say that after 18 years, the 85kWh pack has roughly the equivalent range of a 60kWh pack. Likewise, after 18 years, the 60kWh pack has roughly the equivalent range of a 40kWh pack.

So one could conclude that battery-related depreciation cost of the Model S is only $10,000 over 18 years (the cost difference between a pack size). That's $46 a month.

[Kevin Sharpe]

In total I've driven 31,868 miles in two years and range has dropped ~6 miles to 226 miles http://www.teslamotorsclub.com/showt...922#post154922

[nrcooled]

In total I've driven 31,868 miles in two years and range has dropped ~6 miles to 226 miles http://www.teslamotorsclub.com/showt...922#post154922

This makes me very comfortable with my choice of the 60 kwh pack. Thanks for your input.

[stopcrazypp]

That's almost definitely a misquote (mishearing 8 years as 18 years or a typo).

Here's what Tesla officially says:

Based on testing, Tesla expects the battery to retain approximately 70% of its initial capacity after seven years or 100,000 miles (160,000 km).

http://www.teslamotors.com/en_HK/models/faq

There's a good point on that thread, which is that the Roadster and Model S's active cooling (which keeps battery temperatures near the optimal temperature that the cells are tested at) means there should be little to no difference in battery degradation based on the ambient temperature of your location. For example, you won't see the large difference in degradation seen in the Leafs in Texas and Arizona. The cost is of course a slight hit to efficiency.

[Incredulocious]

That's almost definitely a misquote (mishearing 8 years as 18 years or a typo).

Here's what Tesla officially says:

http://www.teslamotors.com/en_HK/models/faq

Interesting how that note is not (or no longer?) on the U.S. version of the Facts page.

http://www.teslamotors.com/models/facts

[brianman]

I don't remember language like that ever being on the Facts page.

[Citizen-T]

I don't remember language like that ever being on the Facts page.

I do.

Sent from my DROID RAZR using Tapatalk 2

[mulder1231]

That's very interesting indeed. You could say that after 18 years, the 85kWh pack has roughly the equivalent range of a 60kWh pack. Likewise, after 18 years, the 60kWh pack has roughly the equivalent range of a 40kWh pack.

So one could conclude that battery-related depreciation cost of the Model S is only $10,000 over 18 years (the cost difference between a pack size). That's $46 a month.

Well, if it's 30% loss over 7 years (as per en_HK faq), then the math is a $119 monthly depreciation in value due to the battery degradation.