Model S Battery Pack - Cost Per kWh Estimate

[bluetinc]

Hey Vgrinshpun,


A couple of corrections to your statements:

When tested to the EPA standard, the car is driven until it stops moving or enters "turtle" mode. They do not stop driving the car when the indicator shows 0 miles remaining.

When 0(+) rated miles are shown remaining to the driver, this does not equal a SOC of 0%, rather ~6%.


Peter

The EPA numbers that are used by Tesla as the "Rated" capacity of the battery actually indicate that battery is 85kWh, but 5% of it is "reserved", i.e. when battery indicator shows 0 rated miles (0% state of charge), there is actually a 5% reserve left in the "tank".

The numbers used by EPA and Tesla:
Rated range = 265 miles
Rated power consumption = 0.3kWh/mile

Using above assumption that 265 rated miles equal to 95% state of charge of 85 kWh battery, the calculated rated power consumtion:
0.95 x 85 / 265 = .305 kWh/miles, i.e. essentially the same number used by EPA and Tesla as rated power consumption.

There is another interesting number used by EPA as overall power usage: 38kWh per 100 miles driven. I believe that this number is higher than rated number because it takes into account charging and battery efficiency as well as vampire load.

 

[vgrinshpun]

Thanks for clarification, it is a good point, Peter, but I do not think that any corrections are needed to the post :smile:

Model S does switch into limp mode when battery is at 5%; from the Manual:

Discharging the Battery to 0% may permanently damage the Battery.To protect against a complete discharge, Model S enters a low-powerconsumption mode when the charge level drops to 5%. In this mode, theBattery stops supporting the onboard electronics to slow the discharge rateto approximately 4% per month. Once this low-power consumption mode isactive, it’s important to plug in Model S within two months to avoid Battery​

damage.

The EPA started at 100% state of charge, drove 265 miles until car got to the power limited mode at the state of charge of 5%, per the SAE-J1634 test procedure. Since Tesla adopted to show EPA numbers, rather than state of charge , in order to be consistent with the EPA data, Model S displays 265 rated miles at 100% of charge, 0 rated miles at 5% of charge, and 0.3kWh/miles as rated power consumption on the power consumtion graph.

My conclusion is speculative, but based on logic: there is no other way to make numbers displayed by Model S consistent to each other.

 

[bluetinc]

I don't want to take this thread too far off topic. There are other ways to explain the displayed numbers that fit the observed results much better. As a main note, if you charge your car up to 265 miles and then drive at exactly 306/308 Wh/mi, you will not make it to 265 miles when you hit 0, rather you will have driven about 249 miles. Here is the most relevant thread from over on the Tesla site.

Peter

Sign into My Tesla | Tesla Motors

Thanks for clarification, it is a good point, Peter, but I do not think that any corrections are needed to the post :smile:

Model S does switch into limp mode when battery is at 5%; from the Manual:

Discharging the Battery to 0% may permanently damage the Battery.To protect against a complete discharge, Model S enters a low-powerconsumption mode when the charge level drops to 5%. In this mode, theBattery stops supporting the onboard electronics to slow the discharge rateto approximately 4% per month. Once this low-power consumption mode isactive, it’s important to plug in Model S within two months to avoid Battery​

damage.

The EPA started at 100% state of charge, drove 265 miles until car got to the power limited mode at the state of charge of 5%, per the SAE-J1634 test procedure. Since Tesla adopted to show EPA numbers, rather than state of charge , in order to be consistent with the EPA data, Model S displays 265 rated miles at 100% of charge, 0 rated miles at 5% of charge, and 0.3kWh/miles as rated power consumption on the power consumtion graph.

My conclusion is speculative, but based on logic: there is no other way to make numbers displayed by Model S consistent to each other.

 

[DonPedro]

Driving profits: Panasonic to expand in lithium-ion batteries

In addition to the main news, note:

Sony Corp, another struggling Japanese electronics maker, has said it may sell its lithium-ion battery business, which makes small batteries for PCs, tablets and mobile phones.

 

[Buran]

Driving profits: Panasonic to expand in lithium-ion batteries

In addition to the main news, note:

That's about as clear as it gets. Panasonic is ramping up production in the Suminoe plant, and committing to more investments in this sector. It is quite telling that the growing demand from Tesla contributed to a turnaround for them. At a margin of 5.8% which must be up from previous bad Qs if the article got it right, this imply that they do make some decent money form selling Tesla 18650 cells. The industry is reportedly only at an average of 5% for all Li-Ion. This in turn, show that if the industry just trust that Tesla is here to stay, they will step up and invest. The margins are quite ok, perhaps even good, for being in the battery manufacturing world.

Thus, this eases my concerns on battery production constraints in several ways:
1) It tells us that the underling costs for Panasonic to produce Tesla's cells is low enough for them to have margins, which also points at lower end price estimates for the cells (e.g., if they have good margins at this production level, higher levels will be even better); and
2) It provides some confirmation for both Panasonic and others that it is profitable to venture further into the 18650 automotive production capacity in the future; finally,
3) Also near term it is good news, as this confirms that capacity increases in small 18650 cells is coming online next spring will support Tesla to expand to the targeted 40000 MS/y end of 2014 and further down the line rampup in Model X.

Great news in all regards I would say!

 

[DonPedro]

Thus, this eases my concerns on battery production constraints in several ways:
1) It tells us that the underling costs for Panasonic to produce Tesla's cells is low enough for them to have margins, which also points at lower end price estimates for the cells (e.g., if they have good margins at this production level, higher levels will be even better); and
2) It provides some confirmation for both Panasonic and others that it is profitable to venture further into the 18650 automotive production capacity in the future; finally,
3) Also near term it is good news, as this confirms that capacity increases in small 18650 cells is coming online next spring will support Tesla to expand to the targeted 40000 MS/y end of 2014 and further down the line rampup in Model X.

Great news in all regards I would say!

+1

Try also to imagine what you do if you are a competitor. I see three options:
(1) Woo Tesla to get a piece of the action
(2) Try to sell your business to Tesla
(3) Target the laptop market, hoping that Tesla gobbles up enough of competitors' capacity to compensate for falling demand

I think (3) is a sunset strategy, but will be the only option for everyone but the 1-3 vendors that get into bed with Tesla. This in turn will make the Tesla-linked vendors even more dependent on the automotive business.

I would think that the current development will lead to even greater consolidation in the 18650 market.

Do we have any idea how much extra capacity these $200 million will buy?

 

[30seconds]

looks like the $200m investment is only for the remainder of this fiscal year for panasonic ("this year to march"). that is a pretty big investment for an off budget cycle commitment. my guess is that they are probably considering a bigger investment over the next couple of years but needed to start spending now due to the demand in 2014 being stronger than anticipated. also very telling is the "turnaround strategy targeting the auto sector" quote.

 

[CapitalistOppressor]

I wonder how much Sony wants for their battery business. If Tesla was going to get an additional supplier besides Panasonic/Samsung, Sony is probably who they would talk to.

 

[DonPedro]

I wonder how much Sony wants for their battery business. If Tesla was going to get an additional supplier besides Panasonic/Samsung, Sony is probably who they would talk to.

If they have been doing as poorly as Panasonic did ex Tesla, I would guess at "not very much".

- - - Updated - - -

I'm guessing that is Tesla were to do anything structural involving batteries, they would not go for a straight acquisition. It would be something more indirect, possibly involving Solar City, private equity, some sort of contractual obligation from Tesla to purchase a given quantity etc.

 

[Zzzz...]

If Tesla was going to get an additional supplier besides Panasonic/Samsung, Sony is probably who they would talk to.

I know that Tesla having at least two battery suppliers is a fact (10-K wording etc). But aren't info that the one of the suppliers is a Samsung just a rumor? I mean I saw an article where analyst was claiming that Samsung is supplying li-ion cells to Tesla. But he did not mentioned his sources of information and whole thing sounded like a guess... May be an educated guess, but nevertheless a guess.

Or have I missed something?

 

[stopcrazypp]

Probably talking about this:
http://www.teslamotorsclub.com/showthread.php/19468-Tesla-in-negotiations-with-Samsung

However, AFAIK, the only publicly announced supplier is Panasonic. 10k wording can be interpreted to mean Panasonic Japan and Sanyo China (essentially the same main company and same cells, but still two different suppliers).

 

[CalDreamin]

An interview with Elon Musk where he discusses the need for a "truly gargantuan battery factory of mind boggling size." He mentions Samsung/LG as a potential supplier.

Musk: - CNBC

 

[DonPedro]

An interview with Elon Musk where he discusses the need for a "truly gargantuan battery factory of mind boggling size." He mentions Samsung/LG as a potential supplier.

Musk: - CNBC

This thread nailed it:

For long term production growth, my single biggest concern is Li-Ion cell supply.

From my point of view:

1. TSLA's share price factors in enormous growth
2. My main concern regarding growth is the production ramp up
3. Elon's main concern for production growth is the cell supply

Assuming this "most important" issue could triple or cripple the share price, it is an issue potentially worth tens of billions of dollars. Elon: "We're going through the exercise right now". Q: "Would you build it?". A: "It's something we're considering".

Great find, CalDreamin!


PS: Elon simply cannot resist sharing info when asked. It does not help to say "again, I don't want to make a big story out of this". The only reason it is not a big story is that CNBC did not realize how important this is.

 

[uselesslogin]

This thread nailed it:



From my point of view:

1. TSLA's share price factors in enormous growth
2. My main concern regarding growth is the production ramp up
3. Elon's main concern for production growth is the cell supply

Assuming this "most important" issue could triple or cripple the share price, it is an issue potentially worth tens of billions of dollars. Elon: "We're going through the exercise right now". Q: "Would you build it?". A: "It's something we're considering".

Great find, CalDreamin!


PS: Elon simply cannot resist sharing info when asked. It does not help to say "again, I don't want to make a big story out of this". The only reason it is not a big story is that CNBC did not realize how important this is.

Here is an interesting comment Elon made during the Q2 conference call BTW:
"If we were to say, what's the ideal cell number and if we were to go whole new cell, like a whole new sort of cell plant, I think we might drop the cell number in half, but probably not less than that."

So, I wonder if 18650 will be used for Gen III or they have a larger cell in mind.

 

[lolachampcar]

"Analysts" on the Q2 call just had Elon's comments fly right by with absolutely no idea of the magnitude of the comment.

I hate to beat a dead horse but someone has to fund this whole exercise. Tesla may gain access to credit lines to fund receivables but it is going to take raw shareholder supplied $s to build the needed capacity (or someone to buy Tesla and fund it).


I just listened to the whole piece. It does not get any clearer than that. He flatly states that global existing capacity (if it all could be secured by Tesla) would only support a couple hundred K of G3 production. Elon goes on to say that if someone else does not build it Tesla will either facilitate it being built or build it themselves.

I see this as the single defining feature of TSLA valuation moving forward. All the rest of G3 can be done; it is not easy but others have shown that it can be done and Tesla is a capable competent company. The real magic is battery supply.

Anyone know the raw material portion of the quadruple existing LiOn production equation?

 

[JRP3]

Here is an interesting comment Elon made during the Q2 conference call BTW:
"If we were to say, what's the ideal cell number and if we were to go whole new cell, like a whole new sort of cell plant, I think we might drop the cell number in half, but probably not less than that."

So, I wonder if 18650 will be used for Gen III or they have a larger cell in mind.

He may be talking about a doubling or more of current 18650 energy density, so same form factor but fewer are needed.

 

[uselesslogin]

He may be talking about a doubling or more of current 18650 energy density, so same form factor but fewer are needed.

Yeah, good point. Of course by larger cell I wasn't thinking much larger. It could be a combination of higher energy density and slightly larger cell size.

 

[lolachampcar]

I would think when you become the dog instead of the tail you would use the least expensive form factor whatever that may be. CO rightly points to moving the safety factor from the cell to the pack thus the least expensive single cell packaging would make the most sense even if it is not 18650 (as you no longer need to ride the volume coat tails of that form factor).

 

[Dave EV]

Yeah, good point. Of course by larger cell I wasn't thinking much larger. It could be a combination of higher energy density and slightly larger cell size.

Ideally, it would be all energy density. For a 85 kWh battery pack to be viable in a smaller car, they have to cut the weight significantly. Cutting the weight in half would be a good target, which would also let you cut the number of cells in half. Hopefully this would come at half the price as well. It really has to be done for medium-range EVs to be viable for the mass market.

 

[CalDreamin]

Here is an interesting comment Elon made during the Q2 conference call BTW:
"If we were to say, what's the ideal cell number and if we were to go whole new cell, like a whole new sort of cell plant, I think we might drop the cell number in half, but probably not less than that."

So, I wonder if 18650 will be used for Gen III or they have a larger cell in mind.

I also thought that was intriguing.

18650 = 18 mm diameter x 65 mm tall cylindrical cell.

I'm thinking Musk would not want the cells significantly taller than 65 mm since that makes the skateboard taller and reduces interior space in the car.

22650, 26650, and 32650 cylindrical format cells already exist with the same 65 mm height, but with 22 mm, 26 mm, and 32 mm diameters, respectively. I have no idea how much investment would be involved to convert a 18650 production line to one of the larger diameter xx650 formats. But as sales grow for Model S, it seems like Tesla is developing leverage to get what they want from suppliers for Gen3. Especially since demand for 18650 cells for other uses has been shrinking.

On a side note: when I think of the arrangement of thousands of cylindrical cells in Tesla's battery pack, the chemical engineer in me is reminded of shell and tube heat exchangers that transfer heat from a hot fluid to a colder fluid. These involve hundreds or sometimes thousands of small diameter cylindrical tubes (typically the hot fluid) within a larger shell that contains the other fluid. When Telsa talks about their battery pack design controlling the thermal runaway potential of the cells better than batteries based on large format cells, that's (in part) the advantage of the high surface to volume ratio of the many small cylinders enabling better heat transfer to the cooling fluid in the pack. I see nothing odd about the many small cylindrical cells concept since it seems (to me) so similar to shell and tube heat exchangers. It seems like a logical engineering solution to me. Have a look at the photos at the link and maybe you'll see what I mean, the Tesla bashers with their "6000 hamsters" comments might think this fundamental chemical engineering design that exists in thousands of heat exchangers x thousands of industrial plants is stupid also:
shell and tube heat exchanger - Google Search