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The 85kWh battery looks like a flat tray and is fitted to the skateboard. Would it be possible to fit 2 flat trays instead of 1?

The hight of the car will be more offcourse. And the car will get heavier. But you will have doubled the amount of electricity that can be stored in 1 charge. The range will also be much more. The range will not be doubled, but it will be significantly more. Maybe 80% more range. Is that possible?

I'd agree with you, Brian but again longer trips would clearly require charging outside of the home. A user on a long trip would want the comfort level associated with the ability to quickly (<30 mins perhaps) recharge from anywhere.


I envision a 500 or more mile range capable BEV. I read some time ago about a company that was experimenting in making batteries in different shapes. In theory with inert battery chemistry one could construct the car structure itself out of live cells.

The S weighs approx 4700 lbs. including approx. a 1600 lb. battery pack. Suppose their research came to fruition? While overall weight remains @ 4700 lbs. if the chassis and stressed members themselves could provide energy storage one could theoretically construct a 4700 lb. car where 3000 lbs. or more? was energy storage. The car itself becomes the battery. as opposed to building a car and placing a battery in it.

Since the overall weight remains constant the performance would not suffer in fact it should improve as far as acceleration. Handling might suffer due to a higher CG

The T-Zero used a rather innovative approach to battery placement although the car itself was not very practical but the Roadster was only marginally better mostly by adding creature comforts.

Nobody thought there would be a car such as the Model S either as recently as 10 years ago. All the heavy hitters said it could not be done. Good thing Elon did not listen to them.

As always the people who say something cannot be done are in the way of those who are doing it!

These batteries..

can be made in any shape. tomorrows technology is being built. As my hero Mr. Spock was fond of saying "I'd like to think there are always possibilities"


I think your estimate about battery weight is a bit high. 8000 (~89kWh) * 46g (each) gives only 368kg which is about 811 lbs. I don't think pack structure, wires & cooling quite double that weight even with bottom armor that probably is a bit thicker than ordinary cars have.

Also doubling the battery amount would not require that bottom armor being any thicker, so that doesn't count in adding more batteries.

The Model S battery assembly is 0.16 kWh per kg

That gives 531kg for 85kWh pack. 1170 lbs.

BTW, Kleist, where did you get that info?

Dave Duff - Stanford Seminar video.

Suppose that Tesla one day would manufacture an all electric Bus which has at least 60 seats for the passengers. Now, that is a vehicle that has a lot of room in the floor, because the giant size of the floor itself, and because all the seats are pretty high from the ground. So, there will be lots of space to store a whole lot of (18650) batteries. How about that?

Where is that bus going?

The hight of the battery pack (which is now used for the Tesla Model S) is only 4 inches!!! I thought it was 8 inches high. So, the hight shouldn't be a real problem (2x4=8). But the extra weight of the second battery pack will make the EV too heavy. So, the weight is actually the real problem. Maybe this idea can be used when battery packs get lighter (2030?).

If Tesla is already offering to let you pre-pay for a 85kWh batt 8 years from now for $12k, its probable that a 170kWh battery will be available for about the same price as an 85kWh battery costs today, roughly $30k.

Using a linear 10.5% discount on the price of batts, if we assume an 85kWh batt costs 30k today, in 8 years it will cost $12.35k for the same batt (new), so that is what Tesla is predicting, about 10.5% reduction in price per kWh per year going forward.

Seeing that most car manufacturers run a model for life of 6-8 years before changing the model design drastically, a Model S 2.0 could easily see a 500+ mile range imho.

You guys that are saying the 170kWh battery will weigh twice as much or ride twice as high are using today's speced batts, not the batts of 8 years from now. The energy density will double, but the weight will stay about the same or maybe even be lighter. Panasonic has increased the 18650 from 2200mAh (45.9g) to 3100mAh (45.7g), and increase of 40% in energy while also gaining .2g in net weight.

I have also seen 3400mAh batts are starting to trickle out and they also weigh about the same.

@ mattmorgret

OK. Improvement of technology is always good.

Yes, improved energy density MEANS more electrons per gm. There's a long way to go before such improvement is at an end.

One day it will be reality.

Maybe in 2030?

Twice the 3.1 with approx 8% annual increase:

2013 3.1
2014 3.348
2015 3.61584
2016 3.9051072
2017 4.217515776
2018 4.55491703808
2019 4.9193104011264
2020 5.312855233216512
2021 5.737883651873833
2022 6.19691434402374

Only 10 years. Also rate probably is faster than 8%, that's quite conservative approximation considering that Si-based Li-ion batteries are at their infancy and at beginning of the tech development speed is usually highest.

@ Timo

That is sooner than I expected. Maybe 2020 is more likely then. And that is not really that far in the future. In my opinion 2020 is near future.

Great content

Timo - Informative table and the magic of compounding. Per your table the equivalent to MS85 could be MS125 with the same number of batteries and at lower price. 440 nominal miles. The car could loose some weight using stronger Al alloys, improved structural design. 10% of weight could mean 6% increase in range. Increased/improved inverter +motor efficiency regeneration, electronics, insulation, etc could add another 5% to range. Even aerodynamics could be improved. Potential to increase nominal range to near 500 miles in 5 years. That would enable to car to address the hi end market and mitigate range anxiety.

Meanwhile, Tesla has to increase the coverage of chargers. I think the 100Amp/240V chargers makes the most sense in cities. hotels, restaurants, etc. They are relatively cheap. If the power is available, it may cost may be $1,000 per hook-up in a places like hotel parking lots or even MacDonald. Most hotels, restaurants got industrial hi capacity, 3 phase hook-up to feed the kitchen, HVAC, etc. Even it the company spends $20,000 per site, that is 50 sites/$1,000,000. Spend $10M that is good for 500 sites, or 10 charging locations in each state, each with 10-20 charging hook-ups. $10M is what a decent shack costs in San Francisco. The hotel or restaurant could charge for electricity and would benefit from the hi end clientele, free advertising by Tesla.

I've heard Elon say 9% per year. So that is 1.41x in 4 years. Also the 85kW battery has been around about a year or more already since it was around during the beta cars stage. So all else being equal we could see 120kW battery packs by early 2016 IMO with no appreciable weight penalty. Because the development of batteries is improving at a basic level we are not at the point where tradeoffs are necessary so I I also believe that the power capacity will likely increase too, so we may be able to utilize a two motor 4 wheel drive system to better effect. You think it is stinking fast now... you wait.
In addition there have been some really good developments and a lot of money in battery research in the last couple of years and I believe some of these will start seeing the light of day in the next few years.

Well the 41% may all occur in one swell foop. With nothing before then.

Brian H,
Most likely. But we wont know for sure till it happens.


People may not realize it but these battery packs may designed to work with ultra-capacitors, with the extra spacing & and individual battery controls, etc. From what I read, capacitors are even explosive, and Elon may already knowingly have solved the problem in advance with his battery pack design. Remember Elon was in an
advanced degree program for ultra-capacitor design.

In ten years graphene capacitors may be ready for mass production with increases of storage and faster charging times. I've heard estimates of efficiency increases of 2-10 times. At the high end point, you could drive coast to coast on one charge. At 3,000 miles a charge, this would greatly reduce the need for superchargers. The carbon lifetime footprint goes away and while other companies are playing catchup, Tesla keeps using the same battery design & patents, that are the same form, just different internal chemistries.

And at that point in 2023, the stock goes to $1500 and allows even more mass production for better car pricing.

I think Elon attended Stanford for 2 days before he went off on a rocket-shopping spree to Russia, so I doubt he picked up much -- unless he had prestored the course material in his eidetic memory.

Between the 2 days of super capacitor and Russian rockets are the internet company episodes.
Same as batteries super capacitors can explode like fire crackers. This trick is to contain and not start a chain reaction like traditional 19th century designs ( Boeing, Leaf, Volt, Fisker,...)
The beauty of the TM design... a single 10Whr battery cell is allowed to misbehave, but the released energy can be dissipated safely.

right, for some reason I menally switched Sanford and PayPal, etc.

I think capacitor short-circuits are a lot dicier to contain than battery overheating. Small mushroom cloud dicier.

Tesla should give a scholarship or two for people who want to study and get an advance degree in super capacitors , anyone want to apply ?

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