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My Conversation with JB Straubel at Hawthorne Battery Swap

Got a chance to attend the swap demo in Hawthorne tonight. Other posts will cover in much more depth.

I did have a chance to have a 10 minute conversation with JB Straubel and got to ask him several questions that have been nagging at me:

1. When will Tesla owners be able to use their own battery pack at home in the same manner that Tesla is using battery backup at Superchargers, including time-of-use (TOU) and grid buffering?

JB pointed me to the Solar City battery backup that Tesla Motors designed and sells through solar city. 10kWh and very expensive. He stated that regulatory and engineering problems prevent owners from having the option of using the car battery for that purpose. He did NOT seem inclined that this would be happening in the future, although I tried to drag it out of him.

2. What is the status of the metal-air patents/range pack in the frunk?

"Some patents don't end up in the working product. However, the tesla cell chemistry is improving and a 4-500 mile pack is not that far away."

3. Is the jump from 90 kwh to 120 kwh charging the last speed increase?

No. The charging speed will be increasing.

4. How do Tesla's 18650 lithium ion cells differ from the off-the-shelf versions?

Tesla is using the 18650 "form factor" but the chemistry and several of the components are designed by Tesla and nobody else has anything as advanced. A regular laptop battery placed into the Model S would short/burn up/fail immediately.

Hope this helps clear the air with some of the wilder speculation. Although . . . things can change.

Great scoops. Many thanks.

So, point 2 is referring to th Li ion chemistry goIng to 500 miles, correct?

....4-500 mile pack is not that far away.

Mother of god...


I specifically asked him about supercapacitors and he said they would be "exploring all technologies" but his comments led me to believe that lithium ion was their future for the near term.

Great questions SamoSam! Thanks for sharing his answers!

Are you sure you didn't have to sign an NDA before talking to him? ;-)



Definitely NOT! :-P

I also had a chance to talk briefly with Franz Van Holzhausen, who was incredibly gracious. But didn't get into any technical discussions.

Elon's mom and kids were also in the audience.

The Swap setup implies serious excavation and equipment installation at "participating locations". Underground stuff & storage. That would be a fascinating looky-loo attraction!


I really want to see how the packs are stacked and if they are the 1/2 MW battery backup Elon discussed with regard to supercharging.

Yeah, and how soon "rental" batteries are retired to the pure backup role. Fascinating logistics etc. implied here.

I would think that you drive up a ramp to get your battery swapped. I can't imagine they'd dig up the SC locations to install bays for the robot and storage space for the batteries:-)

Thanks SamoSam. WRT swapping locations, they have to dig the foundations for the battery storage anyway, so maybe they kill two birds with one stone and use the on-site battery structures as the repository for the swappable batteries? That way they don't have to dig too far down?

I have heard from someone at Tesla that hey are working on 1000mile batteries. Not kidding you.

SamoSam, Thanks for the insight. I am not enthusiastic about the battery swap. This set-up would cost at least $2M and would divert Tesla's limited engineering and capital resources. I would rather see rapid deployment of national supercharger network with each station with 4-6 chargers costing only $150k without the solar panels... or a total of $50M for deploying 300 SCs in the US/Canada. After 3 hours of driving I want to take a break and enjoy a cup of coffee and snack. Swapping batteries is too messy, expensive ($80) just to save 20 min!

Tesla is better off focusing its limited resources in mass producing Model S, X with economies of scale, enough to cut prices. Demand will go up, especially with the supercharger network. Personally, I want my life simple and a 500 mile battery would do.

Elon/TM are solving a market acceptance problem you don't address: fear/concern about loss of ability to travel hi-speed routes without longish pauses to recharge. Those inhibitions exist, regardless of your personal preferences.

The expenses contemplated here are minor on the scale of overall corporate marketing, which TM does with innovation and the resulting free publicity rather than TV and print ads.

I'm with SamoSam. Posted this just before I saw his comment (I swear it was before):

1000 mile batteries? If they get there, then that's it, isn't it? We're done. There will no longer be a reason to have an ICE car. None. Especially with battery swap.

Shoot, even 600 miles.

Personally I could surely live with a 85KwH pack here in Germany (even though I don't have my own garage for charging).
What I'd like to ask is how businesses would see it, however.
Many companies here have their own car fleets or offer leased cars as part of the compensation.
Many sales/executive people do have to travel over 300 miles per day roundtrip. A much improved battery capacity (>=500miles) would certainly make it easier to get rid of mental blockades against EV's when compared to the usually driven long-range diesels of MB, BMW, Audi and VW.
One crucial argument here in favor of EV's is certainly the gas price as it is right now about 1.60/litre, which is about 6.05$/gallon (diesel is a little cheaper).
Is my thinking way off here compared to the US?

Oops, I messed that up: I put "$" sign there but forgot to convert to US$ first, doh. So the mentioned price for a gallon here is about 6.05 EUR, with exchange rate of 1.31/EUR it'd be around 7.93 USD.

You also put it in the wrong place! It precedes the number: $6.05/gal.

Netherlands $8.28 per US Gallon and thousands of charging stations.

Acceptance is growing fast here. But the Tesla Model S costs $ 142.000,- (P85 with most options but not P+) so that will slow sales of the Tesla here a bit.

Would love to see some Superchargers. When the swap costs $60 I would wait 20 minutes for the charge.

On the other hand, we had a "Better place" station at Schiphol and I think that this is also a perfect location for a battery swap station for Tesla once they have lounched the Model X. That would make one hell of a Taxi.

Much better than the Renault Fluence or the Nissan Leaf!

Ladies and Gentlemen,

In behalf of State fund innovative technologies of Republic Kazakhstan I pray to provide the list of all necessary documents for conclusion of a contract and opening of official representation of Tesla Motors Kazakhstan on the territory of our republic.

Соoperation with our republic will provide your Company not only additional outputs to our market, but also it will give you possibilities for delivering of your electric Cars to following countries:

Russia (free export from Kazakhstan in terms of Custom Union)

All these countries are neighbors of our Republic.

Through state support of our project we are planning 20% reducing of car number with petrol and diesel motors and replacing them with electric Cars Tesla. We are also interested in Fast Charging Stations for electric Cars, we want to know the cost of spare parts and frame elements. If the personal meeting is necessary for conclusion of contract, I ask you to give date and time. To business ethics and partner I beg you to have talks about opening of official representation in Republic Kazakhstan directly with me.

Yours Faithfully,

Project Specialist

Ok Artem, i'll call you before I would do such a thing.. ;)

Regarding the swap station, I am also supriced and a little sceptical to puuting them by the SCs. But I also admit Elon is lifghyears smarter than I am and on top of that he sits on all the information. So if we ignore all the bad things about complicated machinery and that swaps might get more complicated with dirt, rain, snow... And that a $20k battery (or 50 of them) could be subject to theft. And all other things previously mentioned.

So that said, istn't tesla just pointing out what can be done? Maybe along SCs is not the best idea, but could it open for third party involvement (as he mentioned). And imagine a transport/taxi fleet having their own swap station in bigger cities. And for me at least, it all the sudden got so much easier to change battery. We dont know the capacity in 5 years on the batteries, but just the feeling that it takes 90 sec to change it makes the problem a bit smaller. Or when the 1000 mile battery comes maybe I can rent just that over the weekend leaving me satisfied with my 60 or 85 for normal days. I bet more ideas will come up, that perhaps would not have arised if the technique was not out there.

So after the dust settled, I actually like the possibility of swapping. Still would not vote for putting them by scs though. Well, perhaps one to show the stats that people choose free/20 min rather than $80/1 min. As an argument to naysayers.

I agree with GoodReason - once they get the 500 to 600 mile battery, super duper chargers AND get the price down by half or more, its over for ICE and welcome to the third industrial revolution. I think the battery swap will be relegated to the history books once that happens.

@Brian: thank you for correcting me.

I watched several videos and photos that show the structure of Model S. It seems that over time, Tesla will be able to take a look at the various Al and steel alloys available with better tensile, shear, strength, rigidity, and other desirable properties. With improved structural design and materials, I think they could shave off 1,000+ lbs from the current weight of the car that is currently 4,647 lbs or 3,647 without 1,000 batteries. Raw materials may cost a little more, but not enough to make a significant difference, especially if the manufacturing costs are further reduced. The battery pack itself could be further populated to increase the capacity by 50%, while still saving in excess of 500 lbs. The range would be 500 miles!

Significant cost reductions are indeed likely as the company optimizes design, manufacturing processes and the supply chain. Tesla hired expert talent like Gilbert Passin from Toyota who will figure this out.

Model S is on version 1.0 and won Consumer Reports top award. In the next few years, Tesla will certainly improve on Model S. Even Model X may have significant improvements by the time it rolls out in 2015. Tesla has enough cash, if used diligently, to achieve its goals. Still, I would have preferred if they had raised an additional $500M in equity to have enough cushion against contingencies.

I saw this interesting article on Seeking Alpha a while back discussing several Tesla patents related to Metal-Air batteries (1000 mi range):



Taking this info into account, perhaps the longer term use of these swapping locations would be for the faster degrading metal-air battery in a metal-air / lithium-ion hybrid vehicle.

It's also interesting that the Gen-III is scheduled to release near 2017, the same time as the Phinergy.

I saw the one Phinergy video 2 weeks ago, very interesting progress on their part.
TM has certainly a great task ahead to redesign the current internal battery layout to make it a hybrid (partitioned in metal-air and lithium-ion battery sections). So the base lithium-ion range may be a only a little less than today, but will get charged on-the-fly by the metal-air pack, thus overall extending range by a certain factor, maybe 1.5 or 2.0.
Still some time to see anything official, but the patents show how R&D-heavy TM is and it'll surely get extremely exciting then (even more than it already is).

I can't see spending $80 to swap my battery for another one that might be already worn just to save 15 minutes. If Tesla is really planning on implementing a swapping system, it seems to me that they would have to eliminate the current battery warranties for the users of this system and maybe allow them to start a new unlimited battery warranty? This could be done by charging the users a fee (yearly or monthly) that extends their battery warranty for ever and allows unlimited swapping. The fees collected by Tesla would cover the replacement of wearing batteries and the maintenance of the facilities. If and when new battery technology becomes available, Tesla could possibly place the newer batteries at the swapping facilities and allow owners to automatically upgrade their batteries automatically. The fees to cover this could also be included in the battery warranty fees. Just an idea.

Before building swapping station, I would like to see Tesla survey all of the current and prospective buyers and find out if there really is a demand for them. Also, since the building swapping stations will be a huge expense, I sure hope that Tesla starts with a couple of test facilities to see if there really is a demand for them before they throw away a ton of cash.

Didn't Elon say that battery swapping would cost about the same as a tank of gas? Well, the tank of gas we saw during the swap cost $99. Given how choreographed this event was, I think it is also setting us up for the "almost $100" battery swap fee. When Elon says it will cost about the same as a tank of gas, he isn't referring to a Prius filling up a 10 gallon tank of 87 octane in Phoenix. That would cost $30-$40. Instead, I think we should expect the cost to be closer to filling up the tank of an Audio A8 with premium gas in California and as shown in the demo. Maybe I'm just reading too much into the demo.

Unless I'm going to miss a flight or something, I can't foresee a situation where I would pay even $30 for a battery swap if I can accomplish the same thing with 40 minutes of charging. Even at $30, the battery swap will give me, at most, another 265 miles of range. That is 11 cents per mile. I average about 450 miles per tank in my Prius, so a full tank at $30 costs me just under 7 cents per mile. On a cost-per-mile basis, the swap makes absolutely no sense - and I'm presuming a really inexpensive swap at $30.

you are comparing 7 cents in a Prius to 11 cents in a MS... actually that is no comparison.
Also the swap fee doesn't give you 265 miles... it gives you a trip to the next swap station on average. Personally I don't think swap will be used by many... but it might be a good fit for some people.

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