Have a look at this data before you make any predictions about larger battery packs: 14 Oct 2010vimeo t=34:26
Elon Musk: "The need for recharge stations and battery pack swap stations drops with the square of the range because that defines the area you are able to cover. As the range gets bigger and bigger the need for recharge stations drops quite a bit. Arguably if you get to about 500 mile range, you don't need any charge stations apart from the hotel you are staying in because almost nobody drives more than 500 mile a day."
Teo: This shows that 500 mile range is Elon's long term plan. That is why superchargers are free for life because most of them wont be needed in the future. Elon will repeat this 500 mile number many times in following years.Nov 2012Youtube time=40m
40:00 to 40:45.
Elon Musk: ... lithium-ion batteries continue to improve. Roughly, on average, maybe 8% or 9% per year. Which, when compounded over several years, ends up being a meaningful improvement.Feb 2014, OsloYoutube time=7m10s
Elon Musk: "There is potential for bigger battery packs in the future but it will probably be maybe next year or something like that." Mar 2014:Youtube time=30m06s
From 30:06 to 32:20.
Tesla co-founder Marc Tarpenning gave a presentation about Tesla. He talks about battery improvements. If you switch to HD you can see a chart that shows 7.5% improvement per year. May 2014Youtube t=5m19s
From 5:19 to 8:15.
JB Straubel talked about battery improvements. Jun 2014Youtube t=1h6m31s
From 1:06:31 to 1:07:28.
At the Annual Shareholder Meeting Elon said the following:
Elon Musk (3 Jun 2014): "You should expect to see a steady increase in range, the available range in the cars over time."July 2014youtube t=25m23s
25:23 to 27:37.
Tesla Conference Call:
25:23 Journalist: On the Gigafactory, is the chemistry going to be the same battery chemistry that you're currently using or is that part of the discussions that are going on with Panasonic?
25:34 Elon Musk: There are improvements to the chemistry, as well as improvements to the geometry of the cell. So we would expect to see an energy density improvement and of course a significant cost improvement. JB, do you want to add anything?
25:53 JB Straubel: Yeah, that's right. The cathode and anode materials themselves are next generation. We're seeing improvements in the maybe 10% to 15% range on the chemistry itself.
26:09 Elon Musk:Yeah, in terms of energy density.
26:09 JB Straubel: Energy density. And then we're also customizing the cell shape and size to further improve the cost efficiency of the cell and our packaging efficiency.
26:22 Elon Musk: Right. We've done a lot of modeling trying to figure out what's the optimal cell size. And it's really not much. It's not a lot different from where we are right now but we're sort of in the roughly 10% more diameter, maybe 10% more height. But then the cubic function effectively ends up being just from a geometry standpoint probably a third more energy for the cell or maybe 30%. And then the actual energy density per unit mass increases.
27:09 JB Straubel: Yeah. Fundamentally the chemistry of what's inside is what really defines the cost position. It's often debated what shape and size, but at this point we're developing basically what we feel is the optimum shape and size for the best cost efficiency for an automotive cell.
27:25 Elon Musk:Yeah.
27:28 Journalist: The chemical formula will be the same, it's just shaped differently or?
27:32 Elon Musk: No.
27:32 JB Straubel:No.
27:35 Journalist: Is it a different formula?
27:37 Elon Musk: Yeah.
Teo: JB said 10 to 15% improvement in energy density due to improved chemistry. At 10% improvement that would be 1.1*85= 93.5 kWh. At 15%, 1.15*85= 97.75 kWh. Therefore 95 kWh is the most likely size.21 Jul 2014
Journalist: How far will a battery-powered car be able to go?Elon Musk: "It will be possible to have a 500-mile range car. In fact we could do it quite soon, but it would increase the price. Over time you could expect to have that kind of range."
Source: http://www.autoexpress.co.uk/tesla/87943/elon-musk-tesla-boss-on-evs-with-500-mile-range-and-colonies-on-marsOct 2014
At SoCal Energy Summit JB Straubel used the following image in his presentation. 24 Oct 2014
Elon Musk said "For a cell that doesn't have lots of other drawbacks we are at roughly 300 Wh/kg"
38m 05s: LINK
. However, according the following article from 27 Feb 2012, "Model S batteries should weigh in at around 240 Wh/kg" Source: LINK
Teo: 240 to 300 Wh/kg in 2.5 years is too much. Elon seems to be talking about lab level cells. These are not the 10-15% better Gigafactory cells. These are the cells after that. Here is a calculation:
12% improvement on current cells = 240*1.12= 269 Wh/kg (this is the initial Gigafactory cell)
Another 12% improvement = 269*1.12= 301 Wh/kg (this is next level Gigafactory cell)
Because JB talked specifically about next gen cells at the Gigafactory, his 10-15% energy density improvement statement carries more weight. Therefore I would expect the battery pack to be 95 kWh.5 November 2014youtube t=17m25s
Elon talks about Gigafactory cell improvements: 17:28: With respect to the cathode materials, there is a lot of technology improvements that we will be able to apply to the battery pack and the cathode, anode, separator, can production, the whole works. Some of these improvements are independent to others.17:50: Whatever we build out for the Gigafactory has to work at least at the lab level, let's say this year because we are making monster investments in equipment and there is a certain amount of time, a year or two at least from working at the lab level to working at small scale production. Then at least a year or two after that you can go from small scale production to mass production.
Teo: To me this sounds like Elon is saying the new battery is ready now at lab level but they can't do mass production in 2015 because it needs more time. 7 Nov 2014
Tesla 10-Q Securities and Exchange Commission report had the following information: Source
Quote: Construction continued during the third quarter of 2014 at an accelerated pace with first cells expected to be produced in 2016 for use in Model S and Model X. We plan to use the battery packs manufactured at the Gigafactory for our vehicles, initially for Model S and Model X, and later for our Model 3 vehicle, and stationary storage applications.
This means we know that the Gigafactory will make next gen cells and we also know it will start production in 2016 and additionally we know that those cells will be used in Model S and X. 26 Dec 2014:
Elon tweeted the following:11 Feb 2015
2014 Q4 Conference Call youtube t=1h08m32s
1:08:32 Andrea James: If I read through on the range communication on the Roadster 3.0 and I just apply that sort of same range gain to the Model S, I guess I get a 350 mile to 400 mile range Model S by say 2017. Is that the right kind of, I mean, are the gains there translatable?
1:08:57 Elon Musk: It's difficult to put an exact time on it. Like 2017, probably not in 2017. At some point yes. I don't know if that will be ... it's not 2017 but it might be say 2019 or 2020 or something like that. We could make the Model S go 400 miles today, if we wanted to by just increasing the pack size.
1:09:25 Andrea James: Great. I mean at the same cost, same pack cost. Let's say $22,000 pack, will be 400 mile range the next couple of years, but seems that is a bit too aggressive.
1:09:40 Elon Musk: Next couple years is a bit too aggressive. If you go five years out, that might be the case. That's not a prediction, that's just speculation. But I'd say it's not two years but it might be five years.17 Jul 2015:
Teo: 85 kWh pack was upgraded to 90 kWh. The 90 kWh pack has same number of cells as the 85 kWh pack but the new cells store more energy. 17 Jul 2015:
Conference callyoutube time= 8:39
Elon Musk: "We are shifting the cell chemistry for the upgraded pack cell to partially use silicone in the anode. This is just sort of a baby step in the direction of using silicone in the anode. Still primarily synthetic graphite but over time we will be using increasing amounts of silicone in the anode. The physical size of the pack from the outside will look exactly the same."17 Jul 2015: Blog Post
Elon Musk: "On average, we expect to increase pack capacity by roughly 5% per year."