If you can't tell from this week's video, I've become something of an Elon Musk/Tesla fanboy. We kind of stole a largish portion of their video for today's show. Unfortunately it had some Beat of the Butterfly Wings" music in it that caused us to be banned on YouTube. We have a scant thousand YouTube viewers anyway - mostly those with technical problems with the JWPlayer we use or Apple in general. But the YouTube thing is a constant pain in my battery box. If HTML5 ever gets fully deployed, YouTube will go away at EVTV.
I found the presentation fascinating on a number of levels. Musk was clearly having fun and enjoying the day, and why not? He was delivering early with a car he is clearly pleased with. Of course, there are many questions, but he seems to have better visibility of them than before.
A couple of points I picked up on:
SAFETY: Not my hot button frankly. But of course the key element of the deliveries on June 5 and 6th were that the cars were legally production deliverable. This was because they had passed ALL the regulatory hurdles to reaching that state.
You might recall that the Tesla Roadster caused a Federal fine of $244,000 that Tesla was forced to pay for not having an EMISSIONS CERTIFICATION CERTIFICATE. They had, rightly I think, assumed that since they did not HAVE any emissions, they did not need certification. In fact, to get certified, you have to go on a dynamometer and do an exhaust system sniff test. This isn't even possible to accomplish with a Tesla Roadster. It has no exhaust.
DOesn't matter said the government. You don't really have to pass an emissions test, but you DO have to have the certificate - ergo the fine. What a kuntry.
Musk of course has several very small children and pictures the car as a car HE will drive. Busy with the whole new daddy thing, safety is an issue. They had just completed the crash testing and he was clearly gratified with the results. His issue, not mine. But being against safety is kind of like being against puppies and kittens. Not much future there particularly if you ever want to get laid again.
SALES AND HANDLING. These do not appear to be related. I do relate them. And Musk clearly does as well. One of the things we have learned over and over is that there is a huge disconnect in electric car discussions. It involves a disconnect between those that have driven a good one, and those that have not. And never the twain shall meet.
There is something indefinable in driving an electric car. I have variously and at various times ascribed this to the lack of noise. Or the continuous feeling of acceleration. Or to the very low center of gravity. Or to the sound it DOES make while continuously accelerating. Or....
In truth, I don't know what it is. It is the center and soul of the EV grin. You can't help but smile the first time you feel it. It's a thing your face does automatically and you have no control over it really. What actually causes it I don't know.
In designing the Model S, they did several things that starting with a blank sheet of paper you CAN do with electric drive and you CANNOT do with an ICE car - so no one does.
They put the entire drive train where it belonged, where it drives the wheels. The rear axle and motor and controller all got strangely confused in this car. It is basically a fat rear axle.
That one feat leads to a very unusual car. It has no engine up front. Worse, it has none in the rear either. Polar moment of inertia of mass, or the angular mass, is a measure of an object's resistance to changes to its rotation. The moment of inertia of an object about a given axis describes how difficult it is to change its angular motion about that axis. Therefore, it encompasses not just how much mass the object has overall, but how far each bit of mass is from the axis. The further out the object's mass is, the more rotational inertia the object has, and the more rotational force (torque, the force multiplied by its distance from the axis of rotation) is required to change its rotation rate.
Hmmm. Wikispeak. What this means is that the rotational stability of a car about a central axis roof to floor in the center, is a function of the DISTANCE of the proportions of mass from that center. The car will handle better with the mass in the center than it will at the two ends. With a front engine car, a lot of mass is far forward and with a rear engine car, of course to the rear. This is why MID ENGINE sports cars handle better. And it's why the usual strategy of putting batteries WAY up front and WAY in the rear do not help your vehicle's handling characteristics. IT becomes much less stable and more likely to spin out in a turn.
With the Model S, there is no big mass in the front, and no big mass in the rear. And in fact, most of the mass is in the center. People and Batteries are both in the center between the wheels and in fact the batteries are BENEATH the floor of the car. This contributes a movement of the CENTER OF GRAVITY as well to a very low point, probably beneath your ass level.
The combination of these two have simply not ever BEEN seen in an automobile - lacking perhaps the milk lorries in the United Kingdom during the 1930's. Nobody can design a car with THAT low a center of gravity and that minimal a polar moment - until now.
If you couple that handling characteristic with the usual elements of an EV grin, you have a driving experience that you cannot describe because there is no analogue to it. You've either felt it or you haven't.
So far extremely few have. And therein lies a tale. Tesla did a very smart thing several years ago. They started taking deposits to gage interest in the car. But unlike Nissan with their $99 salutary refundable deposit, Teslas wa a pretty handsome$5000. I'm number 2873. But they now have 10,000 reservations in hand or 50 million in deposits.
Those serious enough to put down a $5000 deposit a year or more in advance all share one thing in common. NONE of them have ever driven the car. Musk of course has. And so he has a kind of double EVgrin.
He gets to grin from driving it. And then he gets another grin when he contemplates that he has $50 million in deposits for the car from people who have never driven or felt it. If 10,000 people will plunk down $5000 for a chance to drive a car that looks a lot like what modern European sedans look like these days, what would people who actually got to test drive the vehicle do? And so he's pretty confident he can sell 20,000 of these next year. His only concern is can he PRODUCE 20,000 of them next year.
I don't know that it will be THAT easy. In Missouri we say that it takes a mighty big dog to weigh a ton. And 20,000 is a BIG number when you get into the stratified air of the premium auto market - particularly at the $87,000 level. That's the number that keeps surfacing on an attractively equipped 300 mile range version. I was kind of hoping those would come in at $77,500, which I predicted two years ago would be the price of their $50,000 Model S.
But then again, I've never driven the car.
Just a few months ago I faulted Tesla for announcing a proprietary charging plug. I hadn't quite thought that through I'm afraid. If you are going to do a fast charge in less than an hour on an 85 kWh battery pack, and we had that number then, you are pretty much talking about at least 85 kWh of power through the cord by definition. Musk urges us to think 100 kW. Makes sense.
Neither ChaDemo or the hugely ungainly SAE combi plug proposal can do that level of power, more like half. So our existing combating fast charge standards, will quickly NOT only not be standardized, but won't even charge our cars of just a few years hence if we do get better batteries. How many charge standards do we have to go through here?
Musk claims they have a small attractively engineered plug that can do 100kW of power. That would be an engineering design win all by itself.
Once the 9600 bps modem was released and available, nobody really cared about the 2400 bps standard again. Similarly at 19,200. New technology that offers a significant perceived advantage wipes out standards where they stand. If there's one thing better than a 100 mile range car that can charge in an hour, it's a 300 mile range car that charges in an hour.
In our last episode we talked about what it might take to put a fast charge station every 40 miles on all 47,300 miles of U.S. interstate and came up with a figure of $59 million at $50K per station. I found this an epiphany for me personally.
Now here is Musk, smugly alluding to the Supercharge Network he doesn't want to talk about, but is dying to talk about because he is so excited he's almost jumping up and down.
One of Musks other companies is Solar City. They basically have broken the mold on solar installations by financing the installation and tacking it onto your home mortgage. Your mortgage payment goes up, your utility payment goes down, and you put nothing into it at all. Really ever. The next buyer then pays off the mortgage at the sale.
This little financial innovation has caused Solar City to grow about as fast as they can hire people and buy trucks. They will be doing an IPO I'm told later this summer if the markets are favorable. I really thought Feed In Tarriffs were the way to go to get the solar thing off the ground. Solar City kind of made up their own and are doing well anyway.
Legacy legislation continues to confound and amaze new technologies. In California, it is actually illegal to sell electricity. This is part of the monopoly afforded the utility companies. So you can't take your electricity, mark it up, and sell it to your neighbor. This all kind of made sense in 1918. But doing charge stations for profit becomes a little problematical. The charge station manufacturers have invoked a theory that you are simply charging for access to the station - not the electric grid. That's a little bit thin if not outright dubious. I can see a battle in the future that could be really ugly.
But if you make your OWN electricity and sell it from your own grid, I'm not sure how that all reads. If you made electricity from solar, and stored it in batteries, and sold that to cars, I guess I'm not seeing a problem here. Who can object to what?
California has 8600 miles of "primary" highway out of their 16,800 miles of roads. If you put one every 100 miles, and sprinkled a handful in San Francisco, San Jose, Los Angeles, and San Diego, you could probably come up with about 100 charge stations. They would be a little more expensive with solar and batteries. But at a half a million apiece, that would be $50 million and at $1 million apiece that would be $100 million. And that's not necessarily money down a hole like free public charging stations. Let's say it was $20 to "fillup." I'd pay it. Say the average fillup was 60kWh. In California that's about $18 worth of electricity anyway from the grid. So paying a flat fee of $20 isn't' even an inconvenience.
Good work if you can get it. You're selling sunshine for 30 cents a kilowatt-hour. If 20,000 cars fill up twice a week, we are looking at $38.5 million a year income from an initial investment of $100 million. Each station has to charge 57 cars per day at that 60 kWh. That's 3420 kWh from 4.5 hours of sunshine or a 760 kW array. That's pretty big frankly. I don't know you can do that with batteries for $1 million. But with 38.5 million per year and a more realistic 10 year cap rate, we probably can for $3.85 million per station.
This can scale anywhere you want it to. If Musk just did it in California, and with Solar City's ability to purchase large amounts of solar panels, their costs have to be down around 85 cents per kWh, would this business model catch on nationally? I wouldn't' actually mind some of that action.
This ignores COMPLETELY that gasoline stations don't make squat on gasoline at all. ALL their income comes from Twinkies and cokes. We ARE talking about people charging for an hour. What do you have for them to do? Drink coffee and soda. Go to the rest room. Eat. Get online.
Suddenly, the necessary infrastructure looks like a business opportunity instead of a charity event or a place for our government to spend more money.
And the ability to swap batteries in one minute? Oh yes. For those in a hurry. At a bit of up charge. But that's not what that's really about.
What if we sell you an $87,500 Tesla Model S for $67,500 (less $7500), and you can join our SuperCharge network and let us worry about the batteries on the monthly plan. You were going to spend $600 per month on gasoline? Well, how about $400 per month with us for so many miles. Kind of like a cell phone plan.
Solar City is thriving by making the pain go away from installing solar. If we take that lesson and apply it to the electric vehicles, would we be looking somehow for a DIFFERENT outcome?
Guys it is true that Tesla is NOT going to franchise the sale of their automobiles. They are going to own outright all of their own stores and control the sales process totally.
Why then wouldn't' they want to own all of the gas stations that fuel them as well? Solar powered gas stations. Delivering electricity. To Electric cars. Without the pain. Ding dongs and Ho-Hos akimbo.
This thing grows into a huge, vertically integrated recurring revenue engine of unimaginable proportions. Actually unfathomable. The vision is breathtaking both in scope and detail and I am in awe.
Starting to feel the squeeze? He said he was going to make it hurt.
Wanna play "who is smart enough to be an OEM?" and other games for children and the geriatrically feeble minded? I'm talking about you Bob.
We've UPPED our game. Now up yours!
Friday, June 15, 2012
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Jack, I'm one of your Youtube watchers. I have two reasons:
ReplyDelete1. I watch at home on my TV, and there is a nice youtube app on that device.
2. I watch at work during my lunch break, and my employer blocks evtv.me This is fine, they can do whatever they want with their internet connection, but it seems like it's not just my company - the block is initiated by McAfee. If that's the case, I thought you'd like to know about it.
The page I'm presented with has the following information:
Your requested URL has been blocked by the McAfee Web Gateway URL Filter database module. The URL is listed in categories that are not allowed by your administrator at this time.
URL: http://www.evtv.me/
URL Categories: Malicious Sites
Reputation: Medium Risk
Media Type:
Rule Name: Block URLs From List Blocked Categories
I just checked our URL on the McAffee web site and it indicated no records and minimal risk. This was specifically their Web Gateway Product.
DeleteSo McAfee doesn't appear to list us as any kind of risk. And I can't imagine why they would. We have about three HTML pages and the rest of it is video.
We do have the online store and index on another site, but it doesn't have any "malware" or anything like that.
Jack Rickard
Chris,
DeleteMaybe check the podcast option?
I don't know your connected TV type, but many of them support podcasts.
Also, you can easily play them on any PC.
More details can be found on http://evtv.projectooc.com/podcast/index.php or through EVTV.ME - INDEX - EVTV Podcast
I bet the clutz in IT thought EVTV was EZTV. Walk over to the data centre and smack his head in with a brown paper bag.
DeleteAll's said and done. They hate people eating up the bandwidth.
Rick,
ReplyDeleteWe are engaged to build ultra efficient new homes and include multiple alternative technologies in the mortgage.....similar to what Solar City is doing with just solar.
We're even developing an ERV Electric Recreational Vehicle...an e-toy for adults. Our first "unit" is street based, we will then branch out into off road, water & air electric recreational vehicles.
This comment has been removed by the author.
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteGreat show, Jack.
ReplyDeleteI've always imagined 18650 battery modules to resemble flashlight tubes, though thinking about it, those trays for recharging multiple batteries have an interesting form factor as well. (http://www.amazon.com/Titanium-Battery-100-240V-Adapters-MD-1600L/dp/B005UNPM3M) Know anyone with a 3D printer?
Regarding Supercharger stations, I came across something that suggested they might be planning an initial 70 locations in California. That might be totally wrong,and I can't find the reference now, but it's a number I'm looking out for.
Domenick
Interesting show....
ReplyDeleteIn my opinion, Elon Musk will be the next Steve Jobs. Anyway, that is is how I see him. He has redefined the space industry. He redefined on line payments. He is re-defining the car industry. He is redefining the energy industry.
Interestingly enough I visited a power plant today to help select a new control system for a 100 year old coal handling system. It was about 120 degrees in the building and very dirty. I visited a small solar power plant a few weeks ago, it was clean quite and air conditioned! A perfect example of the past and future...
I love the Model S & X. I would love to have one and may well get one some day.
As for the 18650 battery modules, it will be interesting to see what you and the viewer come up with. My thought is that spot welding on wide flat tab wires (Similar to the way solar cells are connected) and using heat shrink to hold them together will be the only realistic way to attach them into modules.
Jeff,
DeleteI think you may be aiming a little low. Given his now proven ability to successfully move from one industry to another and now the probable extreme vertical integration of solar into charging stations to inventing his own charge architecture, Elon is looking to become a more moral and higher minded version of J.D. Rockefeller or possibly Boris Berezovsky.
Or to put it as Jack might, 'he's planning to take over the (auto and transportation) world."
Or my personal favorite way of saying it... Make Bill Gates look like a welfare case.
DeleteActually, Elon Musk reminds me of a modern day Henry J. Kaiser, who was a practical and visionary industrialist, not just an oil man who leveraged his trust money into real estate.
DeleteActually, Elon Musk reminds me of a modern day Henry J. Kaiser, who was a practical and visionary industrialist, not just an oil man who leveraged his trust money into real estate.
DeleteActually, Elon Musk reminds me of an information age Henry J. Kaiser, who was a practical and visionary industrialist, not just a successful oil man, consumer design guru, or sharp-toothed software vendor.
DeleteJust a thought... That model may not apply nearly so well in other parts of the country. I would be inclined to avoid a $20 charge station knowing that 60 kWh is about $5.20 at home. Like most middle class Americans households I have 2 cars available. One can be gas the other electric. The gas one can handle longer trips.
ReplyDeleteOne of my biggest EV interests has more to do with the fact that I drive about 6000 miles a year, including several trips from Seattle to Portland. I'm hard on a gas car because if I commute in it then the engine is cold for about 1/2 of all miles driven. I don't have range anxiety, I have cold engine anxiety (and cold hands -- love electric heat.)
Jack,
ReplyDeleteThanks for this weeks show. I very much enjoyed watching it.
This might be a stupid question, but I was wondering whilst watching the show if it was possible to run a small A123 pack in parallel with the Panasonic 18650 cells to try to get the best of both worlds? Power from the A123s and energy density from the Panasonics. Is that a possibility?
Another great show! Thank you.
ReplyDeleteThe thing that all of these wall street types are missing is that Elon is an engineer. He understands all of this technology and he is not prone to making claims just because it makes good business sense. He makes claims on what he knows what he can deliver.
Wall street is banking on a history of people making outlandish claims and not going through with them. It aint going to happen this time. If Elon does carry out Jack's suppositions wall street wont know what hit them.
Jack & Brian,
ReplyDeleteWe support the ones we trust.
Thank you.
Pete :)
Jack that last sentence gave me an EV grin.
ReplyDeleteMark Bush
This comment has been removed by the author.
ReplyDeleteThanks for taking apart and explaining the 18650 batteries.
ReplyDeleteI 4 at $4.69 each from dealextreme.com and free shipping. Took over a month to get them though.
The site also has customer reviews and the conclusion was that mAh ratings of over 3000 were inflated, but the Trustfires I got were accuratly rated at 2400 mAh.
At $19 for ~10WH for the man in the streets EV? Nah!
ReplyDeleteNot to forget a smaller pack is a pack that is quicker to age due to load and cycle life.
Just had a ride in an EV with a 90KWH pack. Feels soo good!
A Citroen Berlingo. 167V and 180A max. Hey, I want one!
DeleteIt takes all sorts. Thank God for our great experiences.
Chatted to a farmer who borrowed a new Renault Kango electric. He handed it back because the range meter was continuously all over the show. Could not handle his hilly farm roads, town driving then miles leaping up while driving down the motor ways at speed. He's back in his old Citroen van but likes the idea of a Lithium conversion too.
Because Tim wanted to.
DeleteThat's a pretty sick pack for a mini van. At least the Elescalade I understand.
DeleteA rolling resistance snapshot, ~550WH/mile @ 20mph. Weight limit on van. Rear 8 ply cross plies at 67psi and jacked suspension.
DeleteDone 150 miles mixed driving so far and Voltages are nominal.
Considers maybe a small trailer to carry 2/3's and challenged me to burn my brains on the logistics. Probably ending up forgotten in a corner. With the trailer.
Jack,
ReplyDeleteAnother great show. Regarding the small cell module, have you seen this from the guy who started Zero motorcycles?
http://www.ntsworks.com/New_Battery.html
Warren
"We are interested in working with select OEM's on custom battery pack design and licensing."
DeleteNow where have I heard that before?
Nothing has been invented, developed, built, nor discovered a thing. So why should anyone offer them money?
"Our new patent pending interconnection system is entirely different. We mechanically connect the cells together with pressure. It is very difficult to make a reliable pressure contact that can carry up to 10 amps and do it for pennies of cost."
DeleteSounds like he has a prototype already.
Sounds like threaded tie bars, full depth as I'm using.
DeleteJack, victpower carries the panasonic 3100.
ReplyDeleteI inquired about price
4.76$ for 200pcs
4.55$ for 10000pcs
the 2900mAh cell which has almost the same energy is 78 cents cheaper.
also noteworthy are LG cells: (low volume)
2600mAh 3.7v 2.46$ (~255$/kWh)
2800mAh 3.7v 3.00$ (~290$/kWh)
3000mAh 3.7v 3.48$ (~314$/kWh)
low volume through a reseller makes it sound plausible that LGchem auto pouches go for near 200$/kWh. Brian could get on the horn and try to get such cells (the cells the Volt uses).
if A123 is dying we need to diversify and 200$/kWh is not without potency.
btw, it's true laptop cells are typically only 2C so you need a big capacity to drive a car but it's also worth noting that by weight you should think of them as 4C compared to thundersky. so by weight it's comparable. maybe even stronger than thundersky by weight.
Stay cool, Dan. Do not overdo it again and again...!
DeleteMathieu.
I agree with Jack that building a EV battery pack out of 18650 cells is ridiculous. For example I'll examine the eBox battery pack. (I thought this was the neatest car ever.) The battery is made of 96 cells in series by 53 cells in parallel. This works out to 5,088 2 amp-hour cells for a pack voltage of 335 volts at 106 amp-hours or 35.5 kWh.
ReplyDeleteThis is 10,176 connections to make, just to build the modules. Then you have to connect the modules together. Every connection is another component in the circuit and a new potential failure point.
Lithium Cobalt batteries are, as has already been pointed out, very finicky and have a short lifetime. And a failure in one cell can take the out the other 52 in parallel with it.
Granted having the little protective circuit is nice, however it wont allow over driving the batteries for acceleration. The eBox battery has to provide 5.5C peak and those little circuits would cause the car to shut down when you stomp on the peddle. Plus they will not be able to take the voltage of the entire pack when they do cut off. If one group of cells in the middle disconnected and the ends of the pack had a low impedance load the entire 335 volts will appear in reverse at the little cell circuits.
A lot of work just to have a light weight EV battery. Especially when you're by yourself with limited resources.
Regarding the cost of installing the Supercharger stations, Since Tesla doesn't presently advertise and may not need to for some time to come, I look at the Superchargers as a substitute for that. They are going to draw attention permanently to Tesla (I'm sure there will be a lot of signage) and their very existence will create a lot of buzz about Tesla's Model S (and future cars) having the ability to charge much faster than any other presently-made electrics and plug-in hybrids.
ReplyDeleteIndeed, indeed. And/or Solar City as well. So you stop in to Solar City for a nosh and a charge up. A chain of 100 of them saturating the stat. You're a card carrying "member". This thing has so many branding issues it is just egregious. Swilling Coca Cola from your Solar City cup. The place crawling with Teslas.
DeleteReally a place almost entirely limited to very COOL people in COOL cars.
Jack RIckard
The land has to cost something. The HPC box at Harris Ranch CA was installed by an owner. Don't know who pays for electricity but now there is a big Supercharger box there (pix on Recargo) Will that also be free land? Maybe if the proprietor thinks the car owner will be buying overpriced snacks and burgers but will this always be the case for land (parking for two cars) and power?
DeleteJack, I love what you and Brain are doing. You’re kind of doing every type of vehicle. I know in Friday’s show you said use a small number of A123 for a low range high power density pack, and use a large number of 18650 for a high range, and equally high powered pack.
ReplyDeleteHow about a 50p30s pack for the smart car? A pack that could be “moulded” into the car and A low powered city car with a 50 mile range.
I drive around Dublin city and my 1.0 litre VW polo eats petrol. On a long journey it sips it. I never get more that 60 km/hr around the city and my car drinks more than the Irish supporters in Poland…..so frustrating.
Padraic
Use 18650 for the Smart. In case it's not clear above.
DeleteSounds like you need one of those cheap Chinese scooters for in town.
DeleteI have a bicycle and it takes less time to get to work. I use the car on rainy days.
DeleteThis comment has been removed by the author.
ReplyDeleteHope Musk isn't full of Greek tragedy hubris as that never ends well. I wish he would now apply his talents to the mid-range and bring forth a technologically optimized hybrid passenger Zeppelin airship. Maybe ElectronVault's Traction Battery Designer, "a cloud-based application that quickly and easily provides electric vehicle manufacturers with complete specifications, cost calculations and delivery dates for production-ready traction battery systems," is something to consider with the cylindrical batteries. That political commercial is the worst ever: alluding to the Catholic church breaking out and heating up the pokers red hot (American Taliban style) is unnerving. Of course, I could be edgy on account of not being able to buy any indulgences, Jack. ;)
ReplyDeleteI'm sorry, simply don't "get it".
ReplyDelete$4.55 for 10WH is $455/KWH +S&H for naked 18650's plus all the hassle and cost housing thousands of them. Then there is the useful life when cycled. The energy density is only valid when new. It has a very poor life so you need a massive pack to get a useful life mileage.
Sorry, I'm out.
Built, Maybe
DeleteBuild? Nope.
the pric ein the end for assembled panassonic 18650 3100 mah cells is not much more than doing a pack with headways. We all know that headway is power so why not give a try with energy density?
ReplyDeleteJack : I'm pretty glad you are considering playing with those cells. I have about 70 of them ( not protected) that I've ordered a few months ago to play with. I did not had a lot of time to do so ; I just moved my little family 600 miles away....
but I understad Andy's point : as you said you might loose as much as 40% of energy density wich brings it back to about 150 WH by Kg. If you consider that you will soon loose another 30% of capacity after a couple hundreds of cycles, it goes back to about 100 WH by Kg wich is what LiFePO4 give us.
But all that is when you consider only this particular panassonic ncr-18650A 3100 mAh cell...
wouldn't it be nice to have a kind of honeycomb case where one could fit any kind of 18650 cells in it : cheap if one want to go for it, power dense (A123 has a 18650 LiFePO4 18650 format cells) or energy dense like the panasonic already on the market.. or the ones that will come in the future :)
Lets face it: unless Winston Battery release their lithium sulfur cells, we don't have lots of other ways (is there any?) to have a long range electric car.
I am also quite curious of your opinion about what Nick mentionned : mixing A123 pouch with Panasonic ?
ReplyDeletenickkkkk and Xavier,
DeleteI can see paralleling Panasonic and A123 being done but there are issues. Because they are different chemistries matching the cell counts and charge voltage termination could be a challenge.
At the least you would still need enough Panasonic cells paralleled to handle your maximum average current without meltdown. The A123's would need to be paralleled in quantities to deliver the maximum system current.
Example: Say you want a 300v nominal pack. With the Panasonic you would need 81 cells in series giving a nominal voltage of 299.7 volts. With the A123 you would need 94 cells giving a nominal voltage of 300.8 which is close enough because all this is a little squishy anyway. The charging CV point will be more important however so lets use the 340 volts max for the popular motor controllers as our cutoff point. For the Panasonic cells the CV point is 4.2 volts so you can use only 80 cells in series to not go over that point at full charge. With A123 this would be at the 3.6 volts per cell giving 94 cells. You would want to use the lower of the two voltages as the max CV point. A123 this would be 338.4 and with the Panasonic this would be 336 volts. The other side of the coin is the discharge end. A 94 cell pack of A123 are considered empty at 235 volts (2.5 volts per cell). An 80 cell pack of the Panasonics would be at 2.9 volts per cell. I am thinking you would want to be more conservative on the discharge end with an arrangement like this.
Although it could be made to work I wouldn't consider this as a viable option. A better solution would be using a LiPo type high current pouch cell paralleled with the 18650 cells since the charge and discharge voltage curves are a match. Something like the 6AH Haiyin cells that can do 60C discharge. To get 1400 amps you would need to parallel 4 of them. That would be a 24AH pack. Then you would need to parallel enough Panasonics to maintain your highway current. I am estimating 250 amps and since we don't really know for sure the continuous current of the Panasonic cells lets assume a 2C is ok so 6 amps. This would be 42 cells giving 130ah so a combined total AH would be 154 AH.
See IDEP [intelligent dual energy power] graphic at 2:02 in this video http://www.youtube.com/watch?v=pgdrans77co
DeleteIf your interest is in battery research, consider this link...about high energy density Li/Water; Li/Air and Sulfur batteries:
ReplyDeletehttp://www.polyplus.com/technology.html
Jack,
ReplyDeleteyou mentioned the grey CALB CA batteries in this weeks show.
I found these specs on the CA cells on EV-Powers site:
http://www.ev-power.eu/CALB-40Ah-400Ah/CALB-CA180FI-Lithium-Cell-LiFePO4-3-2V-180Ah.html?cur=1
Can you confirm that these cells output 20C? This would be terrific news as I'm not that interested in maximizing range with a large pack.
Thanks for all your hard work!
20C on a Calb is non maintainable. A theoretical 3 minute discharge to flat. Who do you intend to kill with it? The Voltage sag will be much higher than 10 A123's which will give off far more power and with less heat in that time.
ReplyDelete3C is the normal max discharge rate of a Calb which can kill a fully charged one within 20 minutes.
Andy
DeleteWe have demonstrated a pretty safe and pretty maintainable 8C on a CALB cell in the past on a real car.
But at the same time, I cannot confirm the 20C. In fact, the new grey cells do not list a pulse or 30 second discharge current level. I have requested this information and that request has been passed. BZut I have no on info at the moment.
Yes, we are going to carry CALB cells in our online store and ship them with our straps and bolts and nordlocks. In fact, CALB is looking closely at our connection method. They don't like the expense, but are kind of coming around to my way of thinking on the connections.
Calbs are the best overall EV choice in my opinion too. Can't fault you there Jack.
DeleteSurely 'C' rates on their own are a misnomer because of the associated ever steepening Voltage drop and efficiency letting heat out.
That site also shows absolute maximums before death. If one pays for these things its not sensible to go there. -45C???
Thanks Jack,
DeleteAs EV-Power states a 10C maximum for the old blue CALB cells I just thought that there would be a chance that the new grey CALB CA cells would in fact have a higher pulse rating, or at least sag less with a 10C current draw.
Hopefully CALB will get back to you with the specs!
What are you making?
DeleteAndyj,
DeleteI'm in the process of sourcing a Mazda RX-7 FD3S as it's my favorite car of all time. Most of them are right hand drive over here in Europe so it's a bit of a pain to find a good left hand drive as many of the cars have been abused... I have one that I'm looking at though.
Would really like to keep the car true to it's origins, so thinking of installing a Soliton1 controller with a 11HV motor. To be honest I don't REALLY need the power myself, it's more of a homage to the car, as it was meant to be that way IMHO.
I reckon if you pack carefully, 30KWH , 50 cells @ 180AH (0.354m^3) could be installed, giving you 120 miles and all the power you'll ever need.
DeleteThe RX7 hits 7krpm. Did someone mention an epicyclic gear to gear up a warp?
Ideally, go for something that takes a diesel box.
DeleteYep, those wankel engines are quite revvy... Keeping the final drive ratio at 4.1:1 would be impractical, but I don't see a problem in changing that. Everything usually works out in the end, it's the journey that counts. :)
DeleteSuza,
DeleteIt sounds like you realize you have to change the gearbox and the differential and maybe use larger diameter rear tires.
If you can find a 1st gear no lower than 1.6 to 1. a differential about 2.73 or higher and tires bigger than 26" in diameter. This is because a series /wound motor that makes it maximum horsepower below 3,000 r.p.m. The following is a link to a gear chart for your RX7 Notice with this set up, because it is geared so low that you probably would be starting off in 3rd gear if you clutch could handle it.
http://xse.com/leres/bin/gearratio?title=SS+%23670+with+MM6+manual+and+3.73+gears&rpm=3000&mph=100&gear1=3.48&gear2=2.02&gear3=1.39&gear4=1.00&gear5=0.79&reverse=3.28&axle=4.10&tire=diameter&diameter=26.00&circumference=81.68&revs=776§ion=&profile=&wheel=
Good luck in your search, You do not have many options to make it all work for performance.
Mark Yormark
Thanks Mark,
DeleteI know that the gearing of the RX-7 is a mismatch for electric use and I'm not against making the necessary changes as this is one of the few cars I really like. The project is more of a hobby, not a necessity or a daily driver. :)
To be honest this car has been an ongoing project on paper for quite a while, but I haven't been that interested in investing in the A123 or Headway cells (because of the form factor), and the smaller blue CALBS (100AH or less) are somewhat underpowered for the Soliton1. Hopefully these new grey CALBS would bring something new to the table...
The car will drive fine and be very fast without making any changes to the gearing. Just don't use first gear anymore and maybe not even 2nd. This will push everything up where you want it to be. The Wankel peak torque is way up high, around 6000 RPM. The big series DC motors start to drop off about half that. So you start out in a higher gear and shift early. If you want to get to 300kph for a top speed you will need to change things but the car will be more than just fine to drive around. For not too much money you could change the final drive ratio to 3.909 (down from 4.100) but this isn't really enough to notice.
DeleteThe third gen RX-7 is on my short list for my second conversion. They are certainly pretty cars but quite a lot heavier than the 1st gen.
Doug,
DeleteNice to hear that someone else is interested in converting a RX-7. Thanks for the information regarding the 3.909 final drive ratio.
The plan is to build the car as it is and then make changes to the transmission when needed. It would be nice to have the gearing set up so that rpms would be ideal at 55mph or so regarding efficiency.
Yes, the car is a bit on the heavy side, but I guess it could be worse. I'm aiming for a 60 mile range and using the EVSource battery calculator it seems quite attainable with enough of smaller cells.
Top speed is really not a priority.
The rotary engine in the 3rd gen you are thinking about had 217 ft lbs of torque. This occurs with a WarP9 starting at almost 0 RPM and continues up to around 3700 RPM if your voltage is high enough. and you can feed the motor 800 amps. You can see this in Jack's dyno graphs from Speedster Redux. The Tuesday April 12 2011 blog includes these graphs. This is a wider range than the original motor, it is just shifted down into what is actually a more useful rpm range. So a WarP9 equipped 3rd gen RX-7 could be faster than factory.
DeleteI didn't mean to imply it is a heavy car, it isn't but it is heavier than the earlier cars. I will have my 1st gen RX-7 at EVCCon this year.
I don't doubt at all that the car would be great with a WarP9 too.
DeleteThe original RX-7 is such a nice car. It will be great to see it on EVTV! Good luck with the build if it's not ready yet.
A totally solar powered [off grid] Tesla supercharger station which could recharge scores of cars would require a sizable amount of real estate. One option might be to strike a deal with Walmart, installing solar and recharge stations. I'm all for off grid solar recharging of EVs, but it doesn't sound too practical at this point. Hope I'm wrong.
ReplyDeleteYou're not wrong. But after switching to thorium power, no one will care about energy costs or ecological impacts again.
DeleteI would think with that Wankel drive ratio, an AC50 system would be an ideal solution.
ReplyDeleteRoy
Roy,
Delete67 horsepower @ 3000 r.p.m. for the AC50
http://www.thunderstruck-ev.com/ac-50.html
20% of the horsepower at less then half of the r.p.m. of the Wankel in the RX7 FD3S
Mark Yormark
Jack,
ReplyDeleteI opened the box with the straps and bolts and Nordlock washers that I ordered a couple of months ago and just wanted to commend you on the value added abrasive sponge you included... EXCELLENT!!!
Thank You
Mark Bush
You're quite welcome Mark. As you know, we recommend a very light scrubbing of mostly the tops of the battery terminals, which take on a patina of corrosion and oxidation - sometimes almost imperceptible as Aluminum pretty much protects itself with an almost molecular thin layer o oxidation which forms in minutes.
DeleteBy "brightening" those terminals just a bit with that abrasive sponge, you do a surprising amount to ensure a clean tight electrical connection.
Those straps and washers seem like a very simple incremental improvement. I would say that more than any other thing, those tiny bits of metal represent more accurately what we've learned about battery care than any other single thing.
They're a couple of bucks at Lowes. Little enough to include in the shipment and save you a trip down to the hardware store.
But yes, pleased you noticed.
Jack
I use a right angle air powered die grinder with a green plastic finger cleaning wheel. This is the same tool mechanics use to clean gasket surfaces in engines. It is very fast and leaves behind absolutely no residue. I can polish the tops of 24 cells in less than 2 minutes. It often takes more time to get ready for the job than it takes to do the job.
DeleteDan,
ReplyDeleteYou still don't get it. It's not your decision. You're more than welcome to use YouTube. I do. Not everyone wants to do that and for what ever reason he has it is just fine. It's his choice and he has that right to choose. I actually agree with Jack about the URL issue. Forcing me to exclude URL's when I should be able to do so is just plain wrong. I hate it. It sucks. I want to turn you to MY site. YouTube wants you to stay on YouTube. In that light they totally suck. Far from Girly to get ticked because of that. It is a BUSINESS and PERSONAL decision. If I could afford a different avenue I would. I don't do enough video yet to warrant moving elsewhere. So it is YouTube for me URLless and all.
There are other play grounds to go play in you know.
Only foolish in your eyes. You still don't get it Dan.
DeleteI wonder if Amazon is also blocked in some countries like youtube is...
ReplyDeleteSuza,
ReplyDeleteIn my opinion this following combination would be the least costly and most effective way of getting the performance from the current drive-train in your RX7 FD3S with the WARP 11HV with the Soliton providing the battery pack is up to the task.
The only change would replacing the stock IRS 4.1 differential with a Ford 8.8 . IRS 2.73 differential.
You will notice that the gearing,(shifting m.p.h.) is still lower than the stock i.c.e. combination, but then again you will not be making as much horsepower and you are not concerned about going fast.
http://xse.com/leres/bin/gearratio?title=SS+%23670+with+MM6+manual+and+3.73+gears&rpm=3000&mph=100&gear1=3.48&gear2=2.02&gear3=1.39&gear4=1.00&gear5=0.79&reverse=3.28&axle=2.73&tire=diameter&diameter=26.00&circumference=81.68&revs=776§ion=&profile=&wheel=
So how do you mount this Ford 8.8 I.R.S? See attached...
http://team321.com/321HotRodIRS/DifferentialPage.html
Good luck,
MARK YORMARK
And a tougher clutch!
DeleteThanks Mark for the links! That Ford 2.73:1 ratio differential looks interesting. I will have to take a look at the amount of space available and the mounting options when I have the car at hand.
DeleteAndyj,
A tough clutch will absolutely go in during the build.
Here is a link to Jack's dyno test with Speedster Redux. Notice how the maximum horsepower speeds correspond to my above gear chart link.
Deletehttp://jackrickard.blogspot.com/2011/04/graphs-is-always-greener.html
Also notice the torque provided by the Soliton, realizing your plan would be a little different using a Warp 11"HV.
I do not think you would need to even change your clutch unless you would be using a Zilla 2K controller.
Mark Yormark
That gear calculator is real handy, I will have to add the link to my favorites. :)
DeleteI feel the torque provided by the 11HV is great at 1000 amps and would like the car to last a long time, especially keeping the gearbox in place.
You may want to upgrade your brakes also to assure you have greater stopping power for any added mass.
ReplyDeleteHey guys,
ReplyDeleteI have an Elcon DC to DC converter it has a yellow wire and a big red wire on one bundle then a not as big black and another, but not as big red wire on the other bundle... I don't remember how to hook it up. Any ideas what goes where? I think the yellow one is a ground wire
Sure would appreciate your help. The "manual" is useless
Keep On Pluggin
Mark J Bush
Figured it Out
ReplyDelete