有位Tesla車主把他買到的P100D拆了之後發現原來電池容量並不是剛好100kWh
而是102.4kWh，這裡面包括了98.4kWh的可用容量跟4kWh的緩衝容量
http://i.imgur.com/rMYvlws.jpg
http://i.imgur.com/WuI6jZY.jpg
http://i.imgur.com/Uiz5ne7.jpg
(第三張照片上方的是85的電池，下方的是剛拆的100電池)
完整的100電池模組有516個電池包，總共有8256顆電池
這些電池規格還是18650，而以後Model 3將會採用2170電池
(我猜以後應該會全車系全面都換成2170)
之前這位車主Jason Hughes拆下85電池時發現其實可用容量只有77kWh，總容量是81kWh
那時Tesla給的回覆是這樣的：
“The battery pack in Model S is designed to meet everyday driving needs
as well as provide long range for road trips. The total available energy
from a battery depends greatly on conditions and can vary based on
factors such discharge rate and temperature. It is very difficult to
replicate the exact discharge profile at home to extract the maximum
available energy in a battery pack.”
最後一段話：
....因為條件的不同.... 在家測量精確的放電曲線得到最大容量是非常困難的....
所以實際容量大概也只有Tesla自己才清楚
這其中的差別可能就是理論值跟實際測量的差別
就像是把1顆電池容量x8256拿來跟8256顆電池組的電池模組的測量值比較一定會有所不同
不過可以確定的是100電池模組裡的電池數量比90電池模組多了約16%
另外這位Jason Hughes打算把這個100電池模組裝到自己的Model X P90D上面升級
(這傢伙有好多Tesla，至少有Model S P85D、P100D、Model X P90D )
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https://goo.gl/MLqOxX
Teardown of new 100 kWh Tesla battery pack reveals new cooling system and
102 kWh capacity
After a teardown of Tesla’s since discontinued 85 kWh battery pack,
long-time Tesla owner and battery tinkerer Jason Hughes was the first to
bring up the fact that Tesla’s packs don’t always have the same
capacity as advertised. He found that the 85 kWh battery pack actually
only had a capacity of up to 81 kWh and ~77 kWh usable capacity.
Hughes got his hands a 100 kWh battery pack and did another teardown to
reveal Tesla’s new cooling system and that it doesn’t have the same
capacity as advertised. Though this time, it’s a higher capacity: 102.4
kWh.
As we reported last month, Hughes cracked Tesla’s battery management
system and reveal all the real total capacity and usable capacity of each
of Tesla’s battery pack except for the 100 kWh, which he didn’t have
access to at the time.
Now he has one after buying what could be the first salvaged Tesla Model
S P100D, which ultimately is what enabled the first teardown of the new
battery pack.
When Tesla first unveiled the 100 kWh battery pack in August, the company
said that the higher energy density was enabled through several
improvements, like a new module and pack architecture, new cooling system
and electronics. CTO JB Straubel described the upgrade as a “significant
change”.
Hughes’ teardown of the pack revealed that the new modules have 516
cells for a total of 8,256 cells per pack. That’s a ~16% increase over
the number of cells in the 85/90 kWh packs.
In a blog post, Hughes describes the new module and cooling architecture:
Basically they crammed a couple more rows of cells into the module. But
what about the rumors around cooling? Well, they did modify the cooling,
but not in any exotic way. The new modules simply have two shorter and
thinner cooling loops per module. This way the coolant doesn’t have to
run past so many cells before exiting.
And he shared a few pictures (the one on the left is a comparison of a
module from a 85 kWh pack (top) vs a module from a 100 kWh (bottom)):
Though the most interesting fact to come out of the teardown is
undoubtedly that even though Tesla usually rounds up the capacity of its
packs, the “100 kWh” is the exception. Hughes says that the BMS
indicates 98.4 kWh of usable capacity plus a 4 kWh buffer for a total of
102.4 kWh.
While it introduces a new module and cooling architecture, the outside of
the pack remains mostly unchanged, which is why Tesla offers it as an
upgrade to other performance versions of the Model S and X. Hughes
described the upgrade process as “plug-and-play for the most part”.
It’s good for him since he is himself going to use the pack in another
car – his Model X P90D that will become a P100D. The guy has so many
Tesla battery packs right now that he is playing musical chair with them
and his Teslas.
It’s also interesting to better understand the 100 kWh pack considering
that Tesla CTO JB Straubel said that it was sort of a test bed for the
third generation battery pack that will be used in the Model 3:
“Some of the key improvements that enabled the new pack are directly on
the roadmap for the technologies that make Model 3 possible.”
Of course, the Model 3’s pack will also feature the new 2170 battery
cells produced at the Gigafactory while the 100 kWh pack still uses the
18650 format, but new cooling and module system could still make it to
the Model 3.