Tuesday, January 11, 2011

Tesla's Dirty Little Secret

We've made no secret of the fact that I'm a bit of a fan of the Tesla Model S. I've taken a significant position in their stock and in fact have done well enough in it that it will basically buy me a Model S. Put in my reservation this morning actually.

I recently received another version of the oft repeated request that we examine making battery modules out of itty bitty batteries after the fashion of Tesla. We typically get 100-110 wH per kilogram with our stodgy old CALB or Thundersky Prismatic cells, while Tesla enjoys 200 mile ranges and over 200 wH per kilogram with their magic sauce battery pack.


There are actually a number of reasons.

The first, is that making that number of connections flawlessly is a herculean task. And as you know, I'm suspicious of connections anway. I actually did by a spot welder and have experimented with it modestly, and we do play around with this a little. I have some K2 cells on the way and we'll probably let Matt weld me up an equivalent battery and do some tests just for your entertainment.

The second reason is that that higher energy density requires quite a bit of cobalt in the cathode. Cobalt is expensive, it is hard to come by, and my problem with it is it is a little bit negative temperature coefficient wise. They are not thermally safe to my way of thinking, at least not in the league with LiFePo4.

Then too, they tend to have limited POWER capability. About 2C is what you can do to these cells, and so you do have to have a lot of them.

But none of that is the real reason I eschew these cells. Tesla of course uses Panasonic 18650 cells. These are little cylinders of 18 mm diameter and a length just slightly over 65 mm.

Let's take a look at a spec sheet for Panasonic's typical recent 18650 lithium ion cell.




Here's the real problem - 300 cycles. LGChem version of the same cell - about the same. Actually, LGChem states >75% of minimum capacity, further fudging the factor.

The bottom line is these are 300 cycle batteries. We could reasonably expect 3000 cycles. A world of difference. Why would I pay DOUBLE the cost of the same size pack, to get 1/10th the life?

The cycle life is the central issue with these cells. It is true that they offer a serious weight and volume advantage over lead acid or NimHd cells, making an electric car viable really for the first time to my way of thinking. But of course the price difference is discouraging. More discouraging is having a reasonably operating lead sled car that in three years is uselss without a new battery pack. LiFePo4 cells pretty much are a lock to 7-10 years if you don't murder them with a BMS. That makes the operation of the car a very different expense.

So after weight and volume, my big item is cycle life. And 300 isn't really any better than lead. Tesla never really mentions the life expectancy of their proprietary pack.

I think I'll like my Model S when it arrives. But I'm not going to be very happy paying Tesla for a proprietary pack every three years. That's the dirty little secret nobody is really talking about. And the Roadsters haven't really been out there long enough for it to come up - though there HAVE already been some under-warranty pack replacements.
It should make Tesla very profitable selling razor blades for these cars - a recurring revenue stream.

Jack Rickard

74 comments:

  1. I wonder if we'll be able to get a 2 pack at Costco?

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  2. Could put in a LIPO4 after warranty.

    Could also us a LIPO4 for commute and a factory for touring.

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  3. Any idea regarding the price tag for a new battery for a Tesla ?

    Is it even a spare that you can buy ?

    Martin.

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  4. Can you drive the car over a plate that does a "live" five minute battery swap?

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  5. This comment has been removed by the author.

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  6. Tesla 6's dirty little secret what Jack is not admitting about is the ACP BMS built into the floor pan battery pack.... And those tunnels above both wheel arches. They really are smoke stacks.

    This way the driver can tootle off first thing in the morning with toasty warm feet.

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  7. Tesla say if you buy a $12000 replace battery as option, so that you have a "spare" battery

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  8. Jack,

    You're not quite comparing apples to apples here are you? The Panasonics fade to about 80% of their original capacity after 300 cycles to 2.5V, which is a 100% discharge. CALB and Thundersky rate their cycle life at 80% or 70% discharge. Do we have any cycle life data for the Panasonics at 70 or 80%?

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  9. I don't know about Panasonics but Headway are claiming > 2000 cycles for their 38120. The power density looks interesting too (10C continuous for 38120S and 15C for 38120P).

    I agree with Jack though. Connections, especially high power connections, are the weevil in the biscuit. The other thing that concerns me is failure modes.

    If these cells ever under any circumstances fail in any way other than complete open circuit then the whole concept is hopeless - unless you plan to equip every cell with a diode...

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  10. John, I don't think it matters.

    The cells are tiny so there will be batches of cells in parallel to make matched sets. *If* a cell does go down. Its a short. Easily seen at service time.

    Put a power diode in and you'll not be able to charge them up. A diode also drops the voltage. Nominally 0.6V.

    Tesla's power supply is so large and discharge volume rates will be so low, I reckon they will last well. Some place A123's into 10,000 cycles and more with sensible use.

    These guys ain't stoopid :)

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  11. Nicholas IducovichJanuary 12, 2011 at 7:27 PM

    A very similar cell powers my flashlight.

    http://industrial.panasonic.com/www-data/pdf2/ACI4000/ACI4000CE17.pdf

    The cell has a PCB protection against overcharge/ over discharge / short circuit attached to it.
    Sorry Jack I didn't want to mention those 3 dirty letters. Seems to make sense with this type of battery chemistry and application though.
    Thanks for the shows.

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  12. I’d like to talk about the Tesla Roadster. As far as I know the Tesla Roadster normally charges to 80 %. You have “tell” it to charge to in “range mode” I think it’s called to charge it to 100 %. According to Tesla the range of the Roadster is 240 miles (386 km)1. Although they advertise 340 km or 212.5 miles 2. So I’m going to go with that. So if you get 212.5 mile/charge to start, and loose 0.1771 mile/charge and drive identical driving pattern until you’re out of power, charge to 100%, and do that 300 times you will drive 52 461 miles (82 000 km). THIS WAS CALCULATED ON THE BACK OF A NAPKIN.
    “The number of miles driven per year is assumed to be 12 000 miles for all passenger vehicles” 3. Interestingly, that is 60 000 miles (96 000 km). Also Tesla’s warranty is for 3 years or 36 000 miles 4. Indecently my girlfriends car is a little over five years old, and has been driven a little over 100 000 km. I’m sure this will be less for two seater roadster. This may help explain then 70 % capacity after five years I have read about, but have credibly reference for. I seem to remember an article (which I can no longer find) on the official Tesla site two years ago which predicted a range of 160 miles after five years. This is somewhat consistent with a ~ 30 % loss in capacity based on 300 cycles at 100 % discharge which would come in at around 60 000 miles (actually it’s more like 55 000 miles) while also considering the loss in capacity as we go. Although this is probably coincidental.
    Cost of Battery Replacement Program from Tesla states: “The battery replacement program fee is $12,000”. You can avail of this after seven years 4. And the warranty is three years or 36 000 miles. I can’t find anything on loss on capacity and how that relates to your warranty. But one could speculate that if you see more than 30 % loss in capacity before 36 000 miles it may indicate a problem which will be covered under the warranty.

    Conclusion:
    Tesla are probably counting on their roadster customers not to clock up so many miles, and not to go through full cycles, it’s a big pack. Their warranty is not as good as what others can offer. But they offer more range currently.
    I think you can see why Tesla went with the batteries. 300 cycles sounds bad, but it’s not like they are completely out of puff at that, and the worst case scenario tells me I can drive over 50 000 miles with those 300 cycles. You still get more range than a Leaf – let’s say. But Tesla are taking a risk if this adversely effect the resale value of their vehicles, or will it? With improvement in battery tech, and increased confidence in the market place concerning EV’s it may not be such a big deal. Especially if Tesla continue to build cars that people want in the luxury market place. But what about the little guy? Sorry, you may have to wait for better/cheaper batteries, or a second hand Tesla if prices depreciate.
    What do we know about the batteries they are using in the S, and their replacement costs which nobody will be considering for 10 plus years. How much will a replacement pack cost then?
    I’d like to go on (I'm tired), and tidy up the above conclusion. But you know where I’m going with it.

    1Tesla online, accessed 11/01/11, http://www.teslamotors.com/blog/roadster-efficiency-and-range
    2 Tesla online, accessed 11/01/11, http://www.teslamotors.com/roadster
    3 EPA online, accessed 11/01/11, http://www.epa.gov/oms/climate/420f05004.htm
    4 Tesla online, accessed 11/01/11http://webarchive.teslamotors.com/display_data.php?data_name=Battery_Replacement

    Padraic

    ReplyDelete
  13. I’d like to talk about the Tesla Roadster. As far as I know the Tesla Roadster normally charges to 80 %. You have “tell” it to charge to in “range mode” I think it’s called to charge it to 100 %. According to Tesla the range of the Roadster is 240 miles (386 km)1. Although they advertise 340 km or 212.5 miles 2. So I’m going to go with that. So if you get 212.5 mile/charge to start, and loose 0.1771 mile/charge and drive identical driving pattern until you’re out of power, charge to 100%, and do that 300 times you will drive 52 461 miles (82 000 km). THIS WAS CALCULATED ON THE BACK OF A NAPKIN.
    “The number of miles driven per year is assumed to be 12 000 miles for all passenger vehicles” 3. Interestingly, that is 60 000 miles (96 000 km). Also Tesla’s warranty is for 3 years or 36 000 miles 4. Indecently my girlfriends car is a little over five years old, and has been driven a little over 100 000 km. I’m sure this will be less for two seater roadster. This may help explain then 70 % capacity after five years I have read about, but have credibly reference for. I seem to remember an article (which I can no longer find) on the official Tesla site two years ago which predicted a range of 160 miles after five years. This is somewhat consistent with a ~ 30 % loss in capacity based on 300 cycles at 100 % discharge which would come in at around 60 000 miles (actually it’s more like 55 000 miles) while also considering the loss in capacity as we go. Although this is probably coincidental.
    Cost of Battery Replacement Program from Tesla states: “The battery replacement program fee is $12,000”. You can avail of this after seven years 4. And the warranty is three years or 36 000 miles. I can’t find anything on loss on capacity and how that relates to your warranty. But one could speculate that if you see more than 30 % loss in capacity before 36 000 miles it may indicate a problem which will be covered under the warranty.

    Conclusion:
    Tesla are probably counting on their roadster customers not to clock up so many miles, and not to go through full cycles, it’s a big pack. Their warranty is not as good as what others can offer. But they offer more range currently.
    I think you can see why Tesla went with the batteries. 300 cycles sounds bad, but it’s not like they are completely out of puff at that, and the worst case scenario tells me I can drive over 50 000 miles with those 300 cycles. You still get more range than a Leaf – let’s say. But Tesla are taking a risk if this adversely effect the resale value of their vehicles, or will it? With improvement in battery tech, and increased confidence in the market place concerning EV’s it may not be such a big deal. Especially if Tesla continue to build cars that people want in the luxury market place. But what about the little guy? Sorry, you may have to wait for better/cheaper batteries, or a second hand Tesla if prices depreciate.
    What do we know about the batteries they are using in the S, and their replacement costs which nobody will be considering for 10 plus years. How much will a replacement pack cost then?
    I’d like to go on, and tidy up the above conclusion. But you know where I’m going with it.

    1Tesla online, accessed 11/01/11, http://www.teslamotors.com/blog/roadster-efficiency-and-range
    2 Tesla online, accessed 11/01/11, http://www.teslamotors.com/roadster
    3 EPA online, accessed 11/01/11, http://www.epa.gov/oms/climate/420f05004.htm
    4 Tesla online, accessed 11/01/11http://webarchive.teslamotors.com/display_data.php?data_name=Battery_Replacement

    Padraic

    ReplyDelete
  14. I’d like to talk about the Tesla Roadster. As far as I know the Tesla Roadster normally charges to 80 %. You have “tell” it to charge to in “range mode” I think it’s called to charge it to 100 %. According to Tesla the range of the Roadster is 240 miles (386 km)1. Although they advertise 340 km or 212.5 miles 2. So I’m going to go with that. So if you get 212.5 mile/charge to start, and loose 0.1771 mile/charge and drive identical driving pattern until you’re out of power, charge to 100%, and do that 300 times you will drive 52 461 miles (82 000 km). THIS WAS CALCULATED ON THE BACK OF A NAPKIN.
    “The number of miles driven per year is assumed to be 12 000 miles for all passenger vehicles” 3. Interestingly, that is 60 000 miles (96 000 km). Also Tesla’s warranty is for 3 years or 36 000 miles 4. Indecently my girlfriends car is a little over five years old, and has been driven a little over 100 000 km. I’m sure this will be less for two seater roadster. This may help explain then 70 % capacity after five years I have read about, but have credibly reference for. I seem to remember an article (which I can no longer find) on the official Tesla site two years ago which predicted a range of 160 miles after five years. This is somewhat consistent with a ~ 30 % loss in capacity based on 300 cycles at 100 % discharge which would come in at around 60 000 miles (actually it’s more like 55 000 miles) while also considering the loss in capacity as we go. Although this is probably coincidental.
    Cost of Battery Replacement Program from Tesla states: “The battery replacement program fee is $12,000”. You can avail of this after seven years 4. And the warranty is three years or 36 000 miles. I can’t find anything on loss on capacity and how that relates to your warranty. But one could speculate that if you see more than 30 % loss in capacity before 36 000 miles it may indicate a problem which will be covered under the warranty.

    Conclusion:
    Tesla are probably counting on their roadster customers not to clock up so many miles, and not to go through full cycles, it’s a big pack. Their warranty is not as good as what others can offer. But they offer more range currently.
    I think you can see why Tesla went with the batteries. 300 cycles sounds bad, but it’s not like they are completely out of puff at that, and the worst case scenario tells me I can drive over 50 000 miles with those 300 cycles. You still get more range than a Leaf – let’s say. But Tesla are taking a risk if this adversely effect the resale value of their vehicles, or will it? With improvement in battery tech, and increased confidence in the market place concerning EV’s it may not be such a big deal. Especially if Tesla continue to build cars that people want in the luxury market place. But what about the little guy? Sorry, you may have to wait for better/cheaper batteries, or a second hand Tesla if prices depreciate.
    What do we know about the batteries they are using in the S, and their replacement costs which nobody will be considering for 10 plus years. How much will a replacement pack cost then?
    I’d like to go on, and tidy up the above conclusion. But you know where I’m going with it.

    1Tesla online, accessed 11/01/11, http://www.teslamotors.com/blog/roadster-efficiency-and-range
    2 Tesla online, accessed 11/01/11, http://www.teslamotors.com/roadster
    3 EPA online, accessed 11/01/11, http://www.epa.gov/oms/climate/420f05004.htm
    4 Tesla online, accessed 11/01/11http://webarchive.teslamotors.com/display_data.php?data_name=Battery_Replacement

    Padraic McDonnell

    ReplyDelete
  15. Hey Jack - I notice Curtis are now listing specs on the much longed for 1238-76xx controlller (650A). Being "in the know" as you are, when are these shipping and when are you upgrading DUH and the Spyder? Or were there rumours of a higher voltage version to come later?

    Wonder what the Vantage green van will go like with one of the spare 1238-6501 controllers? You may have to upgrade the brakes!

    ReplyDelete
  16. Hi Jack,

    I dont think that the tesla battery pack is really a secret. Almost every web article on tesla mentioned that the pack is warranted for 3 years or extended warranty for 5 years. 3 years is definitely more than 300 cycles. So the battery situation is open to the public and not a secret.

    You are thinking about this again because you have reach the practical limits of your prismatic calb batteries for your speedster car: despite batteries on the back, underneath and front, you can only put so much. The tesla roadster, on the other hand, has 53kWhr water cooled bat pack. That's roughly 82 180ah calb bat. which will definitely not fit in the speedster.

    Maybe Elon Musk, who said that air cooled prismatic bat is a "primitive technology", thinks that marketing-wise, longer range is better than longer battery life with shorter range. Toyota and Mercedez benz seem to agree with him.

    JohnM

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  17. John M,
    What manufacturer wants a car to last over a decade?
    I'll go further with that. Manufacturers want to replace unreliability with "serviceable items".
    Same thing when it comes to money. Different thing to peoples perception.

    With a properly set up non-OEM electric car, that service cost chain can be well and truly broken.

    I await hydrostatic transmission/braking; Full LED lighting; true modular construction; includes of course -- Lithium based cells, lol

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  18. All quite good comments. Yes, it is a trade for energy density for battery life. One I do NOT find attractive frankly. True, I live in a small town where a 300 mile range is not a terrible advantage. But one of the most attractive notions to me is the cycle life of these prismatic cells. Actually, they are tested to 100% DOD and we are quite comparing apples to apples. We covered this oddity previously.

    The whole thing validates for me our choice of the larger, more robust prismatics. Not only are there less connections, but the cost of batteries become part of the capital cost of the car, not a 3-5 year consumable item. That strategy just moves the expense from the pump to the battery store. The cells we are using could reasonably be expected to last the life of the car.

    But I was a little shocked to see the spec in print. Next to the ones we use, it looks crippled. And yes, I would expect it creates an ongoing revenue stream for Tesla in battery replacements within a few years.

    Jack Rickard

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  19. Re shorted cells. AndyJ - you are bang on about about diodes and charging - Duh (in my own defence the diodes were a joke). And I'd agree if you have multiple serial strings in parallel

    But if you have the usual topology of clusters of cells in parallel making up a single string it surely does matter. If you have 10 cells in parallel and one goes dead short you have a 9 cells driving current through it and fireworks. If it fails with a high resistance it will quietly bleed those 9 cells flat over time and sooner or later all 10 are toast.

    ReplyDelete
  20. Correct John. I see your fears, But..
    These cells run nowhere near their limits. Remember, they have crazy "C" ratings. Cylindrical cells cannot expand like prismatics due to their construction. Each and every block of cells is a matched set too.

    I haven't stuck my nose in deep with this car but if it's like the GM EV1, there is a connector block where one can plug in a pda to see the state of the cells as a series of cell batches. This is done at service time. Maybe it's viewable on the cars built in TV screen. What can that not do?

    No doubt in operation, like a car, there will also be a temperature probe stuck up a nice warm anode somewhere. >:-)

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  21. Not really cell level management in the TEsla either. The Roadster has 11 modules for about 375 volts I think. Voltage and temperature appears to be measured by module.

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  22. http://www.youtube.com/watch?v=9cfHGDoniU0
    Skip to ~ 2:56, but watch entire video. This is a very interesting video I came across. It’s slightly cryptic, so any conclusions that you may draw from it you’d have to take with a pinch of salt. It’s from the horse’s mouth and I find it interesting. I hope this is new, I know everyone knows a different cell is going into the S, but here is Musk talking about that cell. He also mentions the cell used in the Roadster and a misconception about the cell, or rather the correct conception for the Roadster cell. And he goes on.
    Could he be discussing the life cycle of the cell? As Jack said, yes they compromised life for energy density when it came to the Roadster. But the Roadster is a niche, it’s not mass produced. Its sole purpose was to make electric cars look sexy, and be desirable. It’s an elaborate add campaign for Tesla. Tesla didn’t buy that huge facility from Toyota for no good reason. They intend to mass produce after the S, and are perhaps preparing to mass produce more than they are prepared to shout about at the moment. And it’s a roadster; many of them would be expected NOT to do many kilometres. Although I have heard of high mileage Roadsters, but it’s hard to get information on them.
    The S, and the mysterious X, is different. When we get a sniff of what the battery warranty for the S, and X; that will tell us a lot. If it’s an eight year warranty comparable to the Leaf that will be an indication of more durable cells in terms of cycles.
    I’d love to see a ten year warranty. Is that possible with 18650? I don’t know, but mark my words the mass produced Tesla will have an 8 year warranty. Will the S?
    And I don’t think he’s talking about energy density alone when he’s speaking about the new cell “there’s a mild Moore’s law”. Or I could be wrong, perhaps this E-density/life trade off will continue. I’m more optimistic (but must likely wrong). I hope that this trade off will not continue. By the time I’m 40 I want to be able to buy a 10 year old Tesla S were the battery is not totally jacked. I also want to be able to buy a new Tesla and pass it down to my kids when I’m in my 50s. Does Elon Musk know what I want? I bet he does.
    If I were that reporter I would have drilled him more about the cell. Bit he knew nothing of the cell, and the misconception. What misconception Mr Musk? He should have asked.
    Padraic McDonnell

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  23. http://www.youtube.com/watch?v=9cfHGDoniU0
    Skip to ~ 2:56, but watch entire video. This is a very interesting video I came across. It’s slightly cryptic, so any conclusions that you may draw from it you’d have to take with a pinch of salt. It’s from the horse’s mouth and I find it interesting. I hope this is new, I know everyone knows a different cell is going into the S, but here is Musk talking about that cell. He also mentions the cell used in the Roadster and a misconception about the cell, or rather the correct conception for the Roadster cell. And he goes on.
    Could he be discussing the life cycle of the cell? As Jack said, yes they compromised life for energy density when it came to the Roadster. But the Roadster is a niche, it’s not mass produced. Its sole purpose was to make electric cars look sexy, and be desirable. It’s an elaborate add campaign for Tesla. Tesla didn’t buy that huge facility from Toyota for no good reason. They intend to mass produce after the S, and are perhaps preparing to mass produce more than they are prepared to shout about at the moment. And it’s a roadster; many of them would be expected NOT to do many kilometres. Although I have heard of high mileage Roadsters, but it’s hard to get information on them.
    The S, and the mysterious X, is different. When we get a sniff of what the battery warranty for the S, and X; that will tell us a lot. If it’s an eight year warranty comparable to the Leaf that will be an indication of more durable cells in terms of cycles.
    I’d love to see a ten year warranty. Is that possible with 18650? I don’t know, but mark my words the mass produced Tesla will have an 8 year warranty. Will the S?
    And I don’t think he’s talking about energy density alone when he’s speaking about the new cell “there’s a mild Moore’s law”. Or I could be wrong, perhaps this E-density/life trade off will continue. I’m more optimistic (but must likely wrong). I hope that this trade off will not continue. By the time I’m 40 I want to be able to buy a 10 year old Tesla S were the battery is not totally jacked. I also want to be able to buy a new Tesla and shen i'm finised with it pass it down to my kids when I’m in my 50s. Does Elon Musk know what I want? I bet he does.
    If I were that reporter I would have drilled him more about the cell. Bit he knew nothing of the cell, and the misconception. What misconception Mr Musk? He should have asked.
    Padraic McDonnell

    ReplyDelete
  24. I did watch the video and found it encouraging Padraic. Perhaps they have worked with Panasonic on a newer "custom" cell. Too bad it is not available to us. And perhaps it will be.

    He didnt' address cell life issues, but hopefully that is one of the issues raised.

    The cobalt cells are also specifically the cells with the kind of negative temperature coefficient that led to the laptop/cellphone fires. It's an expensive mineral and a bit touchy as a cathode material, but significantly higher in power density than the phosphate cathodes we use and like.

    Phosphates are improving in energy density. Nickel/cobalt is apparently a bit of improvement toward stability.

    I like this guy. His personality is a little prickly. But his thought process and grasp of all this is striking. His estimate of an 8% per year version of Moore's law is fascinating. I'm hoping for 12% myself but of course we starting with lower density phosphates so it depends on your criteria. Cell life is central to me, looking for advances in density. Energy density central to him, probably looking for advances in cell life.

    Jack Rickard

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  25. Makes a lot of sense Jack. Only 11 pairs of sensors to the battery. Fairly cheap, easily measured. All one needs to stop driver, charger and battery abuse.

    It's exactly what I aspire to be doing.

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  26. Jack
    He didn't mention life, but I hoped that is what he meant. I did forget about the exploding laptop battery business, so that is must likely what he is discussing. Darn it! I really do think for their stage three mass production plan that they need to crack the life cycle.
    Interestingly it is that “custom” cell which I think will allow them reduce the size of the “packaging” of the battery pack thus increasing the energy density of the pack for the S compared to the Roadster. This would be due to a more chemically and physically robust cell less likely to go into thermal run-a-way. “In addition, Musk said that the company’s targeting a 50 percent increase in density at the module level (fitting more lithium-ion cells into each module in the battery pack)” http://gigaom.com/cleantech/tesla-ceo-nissans-leaf-battery-is-primitive/ Not sure if this internet source can be trusted, I’d rather read that directly from Tesla but I can’t find any references.
    So it looks like they may be continuing with the E/life compromise. Or like you said: “Energy density central to him, probably looking for advances in cell life.” But I don’t believe there can be a compromise for mass production.
    12 %/year, so your 180 AH would be a 250 AH in three years. Or a 200 AH, would be nearly 300 AH in three years. I know should go for two years for Moore’s law, but three looks better. I’m excited about that, pity we may not see the same reduction in price!
    I like Musk too, he’s not charismatic but he’s earnest. Which is a quality I would prefer than some charismatic bullshiter or sophist. Like a slimy BMS salesperson. If the BMS people where as obsessed with measuring the pack as a whole rather than each individual we’d be a whole lot better off. Let’s concentrate on getting down to the edge of the curve (So be it to the weakest cell) safely and accurately every time with accurate instrumentation measuring tools on the pack level.
    Best of luck with your roadster, and at the show you’re attending.
    Padraic McDonnell

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  27. Yes, I think the quest for range is misdirected, but very much on the public mind. For my use, 50 miles would be horrendous overkill. But it is a kind of "bragging right" so we too quest for it the Speedster rebuild.

    But the real value is in cycle life. If you could have a car that would go 200,000 miles on set of these cells, much as some of the Nimmies have done, that would be stellar.

    The cost of the batteries going down will be kind of like the PC costs going down. I bought a PC every year for $5000. It was ALWAYS $5000. I just got a lot more PC every year.

    Similarly, THESE cells may go down. But if I could get 500AH in the same weight and volume, I wouldn't want them. I'd want the 500AH version.

    As Elon alluded, it's not going to happen as fast as PCs. But it will behave in the same way.

    If you "wait:" until the price comes down, it will. Unfortunately, that won't be what you want then. You'll always want the latest and greatest.

    The bleeding edge of technology. It is ever so.

    Jack

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  28. Insightful, and I agree.

    Padraic McDonnell

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  29. The pinch point of ones cost/happiness ratio.

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  30. I hope Model S will end up having a tray-like battery container. Tuning that engineering marvel will be the next big thing. DIY a similar one with LiFePO4 cells and follow their upgrades. Once the batteries are taken out of the container could be used as recycled in a fast recharging unit. I suppose within 6 min 80% charge of the new pack of LiFePO4 battery set could be expected. Batteries are not worrying me. I am confident to give the electric car a fair urban use and over time, through advances in energy density packaging, the range will grow. Meaning, as soon as I get my car converted my savings will get better and regardless the car is getting older its economy will improve. With it goes better user experience. It reminds me of my iBook clamshell. It still performs like charms tuned up over time with much more RAM, HD, higher battery autonomy than the original more advanced Mac OS X - in every aspect better computer compared to a brand new tangerine flavored one, bought back in 1999. Besides, it has never been the only computer I was using. Battery technology is ripe for car conversions. Thank you Jack for making this point clear through EVTV weekly programs.

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  31. Nenad, Did you reckon on that 53Kwh pack being recharged in 6 minutes?
    If that is possible you will be recharging at a rate of well over half a megawatt hour at 10C !!

    I would like to see your household wiring if you can handle 1,500 Amps. :-D

    ReplyDelete
  32. @Andyj - I might be wrong, but I boil down potential LiFePO4 battery obsolescence information to this: once removed from the vehicle, if still within their life cycle, batteries could be deployed to accumulate photovoltaic energy. I understood DC-DC transfer is faster than normal charging process. If 6 min is out of proportion error considering household grid and 120 min is closer estimate for bringing new set of larger capacity battery kit to useful level, I am pleased with it. In Barcelona 2h parking on the street can climb up to 6€. For electric vehicles, on ever busy streets some reserved parking space is already provided with up to 120 min charging - free of charge!
    I hope to make the first conversion soon. Investment in LiFePO4 batteries is a safe bet, from my point of view.

    ReplyDelete
  33. With regard to the Telsa battery approach.
    “Tesla’s current battery strategy incorporates proprietary packaging using cells from multiple battery suppliers. This new cell will also be compatible with other cell form factors to enable the continuation of Tesla’s strategy of using cells from multiple suppliers” [1]. Interesting don’t you think?
    You all probably know this. According to my calculations the cell used in the Roadster is 2.3 AH. The 3.1 AH cell with the spec sheet above is probably the same one going into the S [2,3]. The cell it replaces was 2.9 AH. A nominal improvement. But it seems that was not the cell used in the Roadster, so it’s a big step-up from 2.3 AH.
    ASIDE:
    Jack with regard to your show, and whether it will be boom or bust for the electric car. I recon it will be a slow boom, with electric cars common place. Followed by the taking over of electric cars once a tipping point is reached.
    The tipping point being
    i) The beginnings of an infrastructure with places like Tesco (I guess your version of Wall Mart or something like that.) say: Geee, there’s a few electric cars around, how about we place a few charge points in our car park?
    ii) A second hand market of BEVs (these become the second car, a misnomer, they’ll probably will be used more than our current understanding of what a first car is), and cheaper newer EVs.
    iii) Higher scrapage value for the auld bangers because of the lithium, or/and other metals.
    iv) EVs that can be used as a primary car, with a ridiculous over the top ranges of 400 km that will mostly never used. Will Tesla’s model of selling different range batteries stand in the future?
    v) High fuel prices beyond improvements in ICE efficiency.
    vi) True expansion of infrastructure.
    vii) Proliferation of wind power. Perhaps fusion power. Perhaps home power on a home-tech scale (an area I’m interested in).
    viii) Etc
    I also predict, at least to start with, that there will be a lot of superstition with regard to the battery packs. Bad example to follow: “you can only charge it once a week because……..I haven’t a fecking clue but take it on authority that…...”
    I predict car companies, and government doing add campaigns. Such as: “don’t forget to charge”.



    [1] http://www.teslamotors.com/about/press/releases/tesla-and-panasonic-collaborate-develop-nextgeneration-battery-cell-technology
    [2] http://panasonic.co.jp/corp/news/official.data/data.dir/en091218-2/en091218-2.html
    [3] http://www.teslamotors.com/about/press/releases/panasonic-presents-first-electric-vehicle-battery-tesla
    Padraic McDonnell

    ReplyDelete
  34. The german electric Audi A1, which allegedly set an endurance record last october, burned to a crisp. The builder DBM Energy said that only an "incombustible" replacement battery was in the car at the time and that the battery was at no fault.
    In the past they already became famous for having a fire in a forklift equipped with their battery.
    I havent found an english speaking news outlet but here is a german language newspaper link:

    http://www.cleanthinking.de/elektroauto-lekker-mobil-ist-verbrannt/8377/#more-8377

    Philip

    ReplyDelete
  35. another german article with a picture of the burnt down warehouse. The car itself is under a canvas which can be seen on the left side where the roof is completely collapsed.

    http://adacemobility.wordpress.com/2011/01/17/rekordauto-ist-abgebrannt-dbm-bestatigt-adac-recherche/

    ReplyDelete
  36. propellator
    They are saying that the batteries used for the record where not in the car?

    ReplyDelete
  37. Thanks for those links Philip. Very interesting. I wonder what happened. Hm.

    ReplyDelete
  38. BMS!!!!! For Gods sake - how hard is it to put a thermal alarm cutout on these things! The builders of these cars continually FAIL to identify a failure mode and take steps to mitigate it. If one of these "production" cars goes up in flames (taking out someones house or business with it) there will be a class action suit like never seen before.

    If Audi can stuff up like this we are all in trouble. I can see the day when home conversions are all but ILLEGAL and they will MAKE us fit a BMS to prevent burning our cars!

    It has got to the point where if I see a car with BMS on it, I immediately question the sanity of the person building the car. They seem to think the BMS will "take care" of everything.

    I recently got a quote on a Zivan charger but it was specced for 137v CV cutout (38 cells @3.60v) - I wanted 129v (38 cells @3.40v) to keep my cells "happy" and stay under the 130v cutout for the Curtis 1238 controller.
    No can do, perhaps you can "use the BMS to limit the voltage" was the response! I did not want to tell him ('cause they think YOU are nuts) that I wouldn't have a BMS in my house, let alone my car!

    ReplyDelete
  39. One good thing about waiting for price to come down, if you are correct about shelflife/selfdischarge is that an older obsolete battery will be very cheep.

    ReplyDelete
  40. And still have cycles left. Not like a computer where many parts and software make the older so hard to use. People are still building lead acid. They would so jump on LiPO4 if they still can run.

    ReplyDelete
  41. "No can do, perhaps you can "use the BMS to limit the voltage" was the response!"
    Just received my two TCCH-H116.8-18 chargers (aka Elcon) directly from China. They did them to my specs without any problem :)

    Martin.

    ReplyDelete
  42. Just to note, though an Audi was used, it was the battery manufacturer who converted the car. So it is a DIY conversion.
    In the articles it is stated by the battery manf. That the record battery was not in the car at the time of the fire but only a conventional replacement.
    Since the car was subsidised by the German federal ministry of transport, a public investigation by a material science institution (BAM) is ongoing.
    Philip

    ReplyDelete
  43. Thank you. You answered my question about the batteries. I look forward to BAM's report. Do you have an idea of how long it will take for BAM to publish its findings? Assuming they first find a cause, and quickly.

    ReplyDelete
  44. Anyone would think this fire had something to do with all those graphite fuses becoming sparking hot while the battery boils?

    ReplyDelete
  45. I agree that the smoking gun in many of these vehicle fires is a BMS that doesn't shut down the charger.

    I do wonder though whether there are any other plausible causes? It seems to me at least possible that high current through a loose or corroded terminal could cause a hot spot that smoked away for a while before taking hold, perhaps aggravated by a charging current that may be lower than a typical discharge current, but is maintained for longer.

    What do you think Jack? Have you seen anything like that?

    ReplyDelete
  46. I have not John. The connections in a pack and car must be large enough to safely carry the peak currents encountered in driving, with some headroom of course. And those currents are a couple of hundred amps even in NEV like the GEM - never mind 1000 amps in performance vehicles or even more in NEDRA.

    Charging amps are simply hard to come by. 25 is quite a bit. A normal automotive 12 gage wire is often called upon to carry as many as 100 amps in an ICE vehicle.

    So a "loose connection" sounds plausible, but a loose connection of 3/4 inch copper strap can still carry quite a bit of current while dissipating the heat rather well. The scale of the two worlds is simply hard to fathom.

    Other causes. David Andrea, the famed BMS designer of Elithion incendiary devices, first victim was actually done on the road driving. An A123 battery pack. The cause was determined by A123 to NOT be their cells of course, but his module design and specifically a washer in the wrong location leading to a case failure which shorted the cells. I've long suspected this "examination" because of the vested interest of the examiners. But there it is.

    One case in Florida, horrendously touted as an example of why it is SO important to buy one of our BMS systems, turned out to be a conversion so badly done that MOST of the terminals of the pack were shorted to the frame of the vehicle. As it drove down the road it gave off sparks and eventually did catch fire.

    ALL of the really bad fires occurred after many hours of charging, when the charge process should have been terminated - usually by several hours after. This is consistent with our experiments involving very high heat sufficient to melt the cells and lose case integrity, accompanied by venting of the organic solvents used in the electrolyte.

    Note that most of our work involves LiFePo4 cells. Lithium Cobalt cells such as used in Tesla have a bit different set of dangers. Simply overheating these cells can send them into thermal runaway because of their negative temperature coefficient. While incidents involving laptops and cell phones have been fairly well documented, I know of no such incident actually occurring with an automobile.

    We've had "fires" in the nature of burning insulation on wires. Unattended, it is conceivable they could melt through a casing and start one. It has not happened to our knowledge.

    If these cars keep going off like popcorn, and particularly as they take buildings and ships with them, we ARE going to be regulated. I just heard from a viewer in Israel. It is simply against the law to modify a car there at all. That's how extreme it can get. While I cannot imagine such a situation here, they have already regulated cigarette smoking essentially out of existence in many states based on evidence and public harm much less incendiary shall we say.

    Jack Rickard

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  47. I dunno, Jack. I rather agree with you that we're very likely to see some onerous regulation, but for a different reason. I think the danger is real.

    Look at the state of this "industry" today. There are a whole raft of hustlers and charlatans converting cars for people that are likely to, and do in fact, catch fire and burn to the ground. The activity is actually totally unregulated. Worse, there are "experts" who seem to know everything, but mostly that the risks of vehicle damage and fire can be managed by the components they sell, although these vendors and their equipment have been involved in more fires and damage than the entire population of cars that don't use their devices. That is a completely terrible state of affairs to try to defend.

    Far more troubling, though, is that for the hapless hobbyist customer, and especially for the unaware neighbors, fellow ferry passengers and adjacent property owners in EV Land, there is actually some significant risk.

    I don't like regulation any more than the next guy, but its coming and every car/house/ship fire brings it on faster. The first death will seal the deal, and if its a child, watch out.

    In the meantime, the first regulatory problem we're going to have is insurance. Why would a carrier bind a car with a what- 5,000% or 1,000,000% greater chance of catching fire, spontaneously, unattended, wherever its parked? I certainly wouldn't want the risks of my ordinary cars pooled with even a few EVs of unknown quality, nor would I want to own shares in a company that was doing that sort of underwriting for the same premium. The carriers are going to wake up first, and very soon.

    No, Jack, the end of this era is nearly here. We are doing it to ourselves, and there's no way to stop it. The best we can probably do is to help establish some standards, certification procedures, and a scheme to get conversions licensed and insured. Something like they have in Australia, or what is already the case with CNG and LP conversions in NY and many other places. Problem is, the hobbyist is usually locked or priced out of those avenues, which is unfortunate. It can work, though, and that's really the only light I see at the end of the tunnel- that isn't a fire...

    Its sad, but true, and a very old story- the party got too wild, somebody got hurt, and ultimately it was broken up.

    TomA

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  48. Perhaps stricter regulation on the products which are used to modify cars may be a good idea. Is that regulated? I’m sure such companies such as Netgain would have no problem being certified.
    Guy selling 50 circuit boards, plus miscellaneous to monitor each and every cell. More difficult I imagine.
    Just an idea. Perhaps not a good one. But regulate what goes into the car, and you regulate the business.
    Hopefully the batteries won’t be regulated out.

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  49. No, that won't work. It isn't just the parts, its the finished whole that has to be safe. The batteries are great, as are most of the other components involved. The market for them could hardly get smaller, so the good news is the components aren't going to be regulated away so easily.

    The basic EV components (motor, controller, pack, contactors, etc.) aren't the problem- most are already regulated and held to some pretty strict standards. Its the converted cars that are the real problem. The BMS failures are a mixture of error-prone unregulated hardware and ignorant EV conversion charging system design, configuration and/or use. That's deadly, and some of the problem is always the conversion, not just the BMS itself.

    The natural place to regulate is with a safety compliance inspection at the DMV. This is the hard part- there are practically no qualified inspectors. The "experts" are selling BMS systems and doing the conversions. Many if not most of them are incompetent, hence the fires.

    I worry that the only practical way to do this at the government level (e.g. with no money to actually do anything) is to just ban conversions from highway registration. Its not an easy problem to fix with any degree of subtlety.

    As I said, though, if nothing happens at the government level first, once insurance companies get wind of what is really happening with these cars, the whole game may be over anyway.

    I sure wouldn't want to be Elithion's product liability insurance carrier right now, for example. One has to wonder how the manufacturer of such a system can get coverage at all today. Of course, its really only happening through ignorance of the product by the carrier's underwriting department, or misunderstanding by the carrier of the insured manufacturer and what it sells. Neither one of those situations can last very long, particularly if there are claims.

    The very first question I would ask of ANY person or company designing and selling BMS systems, at this point, is to see a copy of their product liability insurance policy. Same question for a "conversion shop" offering implementation services for hire, but in that case it would be liability coverage. If every customer would just demand an answer to those questions, the marginal folks living on their wits in the froth of this perennially nascent business could do far less harm. Some good people would disappear, too, to be sure, but that's a small price to pay to save our hobby.

    Just my $.02

    TomA

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  50. @Nick Smith:
    "I recently got a quote on a Zivan charger but it was specced for 137v CV cutout (38 cells @3.60v) - I wanted 129v (38 cells @3.40v) to keep my cells "happy" and stay under the 130v cutout for the Curtis 1238 controller."

    Just have the Zivan programmed for the #612 charging curve which ends at 3.65vpc. Tell them you have 35 cells for 127.75V cut off or 36 cells for 131.4V cut off. It is relatively easy to make fine voltage adjustments with the cover off the charger. BE CAREFUL. THE COMPONENTS IN SIDE ARE LIVE SO DO THIS AT YOUR OWN RISK! Just make sure your controller is disconnected and charge the pack. When it goes into the "yellow" part of the charging curve it will eventually cut back to zero current if necessary. Turn the voltage calibration pot to bring the voltage up or down. If you lower the voltage you may have to put a small load on the batteries so the charger starts charging again. At least the NG1 will put out only a few mA at the end of charge.

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  51. Nick Smith:

    We're getting a little extreme here and worse, a tad bit confused on some issues. Let's talk about this a little.

    3.40 is a bit extreme on the low side for a charge voltage. Understand there is a world of difference between 3.45 and 3.50 with CALB cells. The spec on these cells is 3.6 volts. We charge to 3.5 volts and the difference between 3.5 and 3.6 volts is actually pretty trivial. It's certainly less than 1.5 Amp hours difference or maybe a MILE in range in most cars.

    We have actually been eyeing reducing this to 3.45 volts per cell. Now I know that looks like half the difference between 3.5 and 3.6 volts. But it IS NOT. In fact, it might be 4 AH difference. You see the curve is a CURVE.

    When you get down to 3.4 volts as a charge voltage, you are probably leaving another 10 AH on the table here. Yes, your cells will last longer, and yes, they will be "safer". But you're paying a price here. MUCH bigger price than the reduction to 3.5 or even 3.45. That range from 3.45 to 3.40 may even be larger than I'm depicting it. They seem to stay at about 3.45 volts FOREVER when charging. They go through 3.6 volts in 20 seconds on their way to the moon.

    Now to the curtis controller. Don't worry about it. AFTER you finish charging, the voltage drops anyway. To about 3.33 or 3.35 volts per cell. At 38 CALB cells you are going to see about 127.3 volts thirty minutes after charge completion. And at that, if the Curtis complains, turn on your headlights for two minutes and you're good to go.

    Jack Rickard

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  52. TomA:

    My what a gloomy picture. The concept of restricting conversions is radical and Obama-esque. It HAS been effectively done with CNG conversions however and I do have a fear of it. If this raft of fires continues, I fear your scenario. But I don't like it.

    What Tom isn't saying, is he had the privilege of going and interviewing a guy who had been the VICTIM of TWO completely separate and incredibly bad conversion services. Some $40,000 they had milked this guy and the conversion was SO bad Tom refused to ride in it. It was a bomb just sitting there, BMS or no BMS.

    The most recent shop to have worked on it had done precisely ONE car before - the owners. And it burst into flames on the highway and burned to the ground in front of him. That was his qualifying conversion to get into the conversion business at all apparently.

    So there ARE indeed some pathetically bad actors out there. I don't know what the answer is, but I'm unalterably opposed to licensing and regulation. I'm also not a big fan of insurance companies.

    But again, he's probably right. If you can't get your car insured, you just can't drive it and it's a sure bet if the fires continue there will be a "book" on it in the insurance industry/casino.

    Why is it there is ALWAYS a kid who just HAS to float a logger in the swimming pool, just as the rest of us are starting to have fun....

    Jack Rickard

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  53. Thanks Tom, well said as usual.
    A gloomy picture, yes, but perhaps a realistic one. But consider this. Is the reason this noise maker Bill was passed because of noise being made from a lobby group?
    What I’m trying to ask is. Are there groups in the U.S. that are opposed to hobbyist doing, well, their hobby? Point is I don’t foresee an outright ban. Although, that’s perhaps not what you are saying.
    I don’t want to float a logger. But I wonder is it possible for car companies to want legislation to prevent their cars from being modified in order to protect their brand name, particularly when they are trying to launch an electric vehicle of their own. For fear that the fire, such as the one discussed above, will be wrongly linked to the car company. Here in Ireland a TV ad showing the dangers of dangerous driving illustrated a well known car knocking a young girl over. As far as I know there was a push to ban the ad. The ad was not banned, but the car was de-badged and disguised. The company feared the car would be seen as being dangerous, not just the driver.
    Kit cars would be a different story by their definition they are modifiable.
    Tom said: “The natural place to regulate is with a safety compliance inspection at the DMV. This is the hard part- there are practically no qualified inspectors”. No qualified inspectors, a pity.
    Paraic

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  54. When I Say hobby above I'm specifically refering to converting cars to EVs.

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  55. No, Padriac, there's no conspiracy.

    The OEMs actually want conversions out there- it helps prove their market and they don't really compete with OEM products anyway.

    No, the problem is that politicians need to be perceived as responsive to constituents' concerns about safety. They will all jump on the "ban conversions" band wagon the first time someone is hurt in a charging fire. We need to see that coming. What I said was the danger is actually real, and it concerns me. That makes the legislative attack on EV conversions really likely, in my opinion.

    This whole scenario went down about 30 years ago with the hobby car (street rod) business. After the second oil crisis, and some fear mongering by politicians, there were laws in the pipeline everywhere restricting and outlawing street rodding, and the cars themselves. Some got passed.

    Then SEMA, and everyone associated with the very big business of street rodding, reacted in concert, pushing back and pointing out, largely on economic grounds, that outlawing an entire industry that was largely safe, self-regulating and everywhere was a silly idea.

    One thing politicians don't like more than being perceived as unresponsive to hazards is being in the way of businesses with jobs and revenue on the books in their patch. The EV community isn't big enough to push back with economics- yet. We do have the green card in our pocket, though, and need to play it when the time comes. It would also behoove the EV community to get under the SEMA tent that protects modified specialty cars and their owners now. There's safety in numbers, and those guys are actually the growth in the EV conversion business anyway. Its also much better for us to be considered the future of hot rodding than it is to be thought of as pioneers of EV road vehicle development before the OEMs took that over. Its just better positioning all the way around.

    I hate regulations as much as Jack, but it doesn't suit me to simply say that and nothing more about it. Regulations are the landscape in which everything automotive happens. Currently we are enjoying practical invisibility in that scheme. That may continue indefinitely, but the car fires have to stop. That's really all I'm saying.

    Its doubly true on the insurance side. Carriers pay much better attention to events (losses) than G-men, so really, the car fires have got to stop.

    They are the turd in the pool; not you or me.

    TomA

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  56. Yes, if that wasn't clear, I was referring to the fires as floaters.

    I guess I think you're right all the way around Tom.

    Jack Rickard

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  57. Tom
    I wasn’t suggesting that there was a conspiracy. I posed the question. Would car companies be interested in legislation to ban conversions of their cars to electric based on fears of a false correlation with a with the burning of a modified car model XYZ, with the company that manufactured the ZYX. I didn’t suggest that the company feared that the XYZ car sales would suffer due to EV conversions. I do not believe that. In fact I see more Kit cars, classic cars, replica sports cars, “different from the norm” cars being converted.

    I guess for the above question the follow you could first ask. Would many lay people on the street tell the difference between the converted EV and its donor car in the event of a fire? We have already seen some confusion on this blog between DMB Energy and Audi with the following comment: “If Audi can stuff up like this we are all in trouble”.

    The possible thoughts of such a person: “Oh I read on a blog (or worse: “ I seen on CNN”) that an electric XYZ car burned to the ground, therefore, in my mind the new electric car from the manufacture of the XYZ car may also burn”. No distinction is made, and a false correlation occurs. HOWEVER, the more I think about it, the more I think that the answer to the question is NO. No as in it won’t the minds of many.

    I agree 100 % with what you had to say about politicians and the popular band wagon. You also paint a less pessimistic picture, and your idea to “behoove the EV community to get under the SEMA tent that protects modified specialty cars and their owners now” is an interesting one.

    You said: “..the car fires have to stop. That's really all I'm saying.” I hear you, and we need more guys like Jack to gather OBJECTIVE EVIDENCE. The identification of failure modes with OBJECTIVE EVIDENCE. The sharing of the OBJECTIVE EVIDENCE, and the methodology for you test this OBJECTIVE EVIDENCE yourself. Not empty rhetoric devoid of OBJECTIVE EVIDENCE.
    A pleasure, thank you for all your information.
    Padraic

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  58. Tom
    I wasn’t suggesting that there was a conspiracy. I posed the question. Would car companies be interested in legislation to ban conversions of their cars to electric based on fears of a false correlation with a with the burning of a modified car model XYZ, with the company that manufactured the ZYX. I didn’t suggest that the company feared that the XYZ car sales would suffer due to EV conversions. I do not believe that. In fact I see more Kit cars, classic cars, replica sports cars, “different from the norm” cars being converted.

    I guess for the above question the follow you could first ask. Would many lay people on the street tell the difference between the converted EV and its donor car in the event of a fire? We have already seen some confusion on this blog between DMB Energy and Audi with the following comment: “If Audi can stuff up like this we are all in trouble”.

    The possible thoughts of such a person: “Oh I read on a blog (or worse: “ I seen on CNN”) that an electric XYZ car burned to the ground, therefore, in my mind the new electric car from the manufacture of the XYZ car may also burn”. No distinction is made, and a false correlation occurs. HOWEVER, the more I think about it, the more I think that the answer to the question is NO. No as in it won’t the minds of many.

    I agree 100 % with what you had to say about politicians and the popular band wagon. You also paint a less pessimistic picture, and your idea to “behoove the EV community to get under the SEMA tent that protects modified specialty cars and their owners now” is an interesting one.

    You said: “..the car fires have to stop. That's really all I'm saying.” I hear you, and we need more guys like Jack to gather OBJECTIVE EVIDENCE. The identification of failure modes with OBJECTIVE EVIDENCE. The sharing of the OBJECTIVE EVIDENCE, and the methodology for you test this OBJECTIVE EVIDENCE yourself. Not empty rhetoric devoid of OBJECTIVE EVIDENCE.
    A pleasure, thank you for all your information.
    Padraic

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  59. Tom
    I wasn’t suggesting that there was a conspiracy. I posed the question. Would car companies be interested in legislation to ban conversions of their cars to electric based on fears of a false correlation with a with the burning of a modified car model XYZ, with the company that manufactured the ZYX. I didn’t suggest that the company feared that the XYZ car sales would suffer due to EV conversions. I do not believe that. In fact I see more Kit cars, classic cars, replica sports cars, “different from the norm” cars being converted.

    I guess for the above question the follow you could first ask. Would many lay people on the street tell the difference between the converted EV and its donor car in the event of a fire? We have already seen some confusion on this blog between DMB Energy and Audi with the following comment: “If Audi can stuff up like this we are all in trouble”.

    The possible thoughts of such a person: “Oh I read on a blog (or worse: “ I seen on CNN”) that an electric XYZ car burned to the ground, therefore, in my mind the new electric car from the manufacture of the XYZ car may also burn”. No distinction is made, and a false correlation occurs. HOWEVER, the more I think about it, the more I think that the answer to the question is NO. No as in it won’t the minds of many.

    I agree 100 % with what you had to say about politicians and the popular band wagon. You also paint a less pessimistic picture, and your idea to “behoove the EV community to get under the SEMA tent that protects modified specialty cars and their owners now” is an interesting one.

    You said: “..the car fires have to stop. That's really all I'm saying.” I hear you, and we need more guys like Jack to gather OBJECTIVE EVIDENCE. The identification of failure modes with OBJECTIVE EVIDENCE. The sharing of the OBJECTIVE EVIDENCE, and the methodology for you test this OBJECTIVE EVIDENCE yourself. Not empty rhetoric devoid of OBJECTIVE EVIDENCE.
    A pleasure, thank you for all your information.
    Padraic

    ReplyDelete
  60. Some of you are having trouble getting posted here. We do NOT remove or review comments here. That was why I left DIY actually.

    But Google is becoming both omniscient and somewhat dark empire. This from their info:

    Spam Inbox

    Blogger now filters comments that are likely spam comments to a Spam Inbox, much like the spam folder in your email. When someone leaves a comment on your blog, it will be reviewed against our spam detector, and comments that are identified as possible spam will be sent to your blog’s Spam Inbox, found at Comments | Spam.

    You can help improve our ability to automatically detect spam comments by checking your Spam Inbox and deleting spam comments and marking real comments that may have been flagged as spam as Not Spam.

    We are always seeking feedback on how to improve this feature, so please share your feedback with us by clicking on the Report Spam Filtering Issues.

    If you have questions about what constitutes spam on Blogger, please review our Content Policies.


    I don't know what you guys do to get marked as spam meisters, and I don't know how to tell you to quit. I cannot turn this feature off. We're looking at other blog venue possibilities. We may go to Word Press or something.... I just don't know how I would move the back items on the blog and hate to start a new one.

    Jack

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  61. Jack

    Being an OTR Truck Driver with limited net access while on the road. I have developed the habit of archiving sites\information for personal consumption when time permits. Much like www.archive.org, but for offline use.

    It might be of value to submit the site for archiving. Removing the need to move the back topics to a new location. It might also be of value to move towards a forum type format which might reduce the amount of cross topic discussion, and provide for a more organized seperation of topics.

    Personally having to sort through endless comments by detractors while looking for valued information makes it difficult and time consumming to seperate the good from the bad.

    Once again I applaude and appreciate the hard work you and the crew do every week to get the information out and educate those that are willing to learn.

    I apologise that my comment might well take this topic disscusion off onto another tangent yet again. The open and valued exchange is greatly appreciated.

    Blind eyes do not see!
    Deaf ears do not hear!
    Closed minds CAN NOT learn!

    Barry

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  62. Barry, Good point, with reservations.
    Opinions can be good or bad. Wandering discussion often brings up salient points we can learn or work out. It's educational, not instructional. I've learned a lot this way. More so than other places.

    However, this is not quite a forum and it's good to keep to the point - short replies.

    I still want jack to place all his math, wisdom and circuit snippets into a single reference page rather than pour through loads of videos. Maybe a tried product sheet too?

    ReplyDelete
  63. Trying to post fast couple of replies in a raw possibly puts us in a Spam Inbox, automatically. I believe this happened to me. This is a test ride and if goes through, black listing was of temporary matter.
    Kind regards to everyone,
    Nenad

    ReplyDelete
  64. Andyj:

    If I engraved it on solid golden tablets and had them delivered to your house, you'd want them on silver plate so you could eat off them.

    I was a magazine publisher. I used to do that. I would love to. The world has moved on. It's video. It's global. We have about 100 hours of it up now.

    I'm a much better writer than I am a tittie blond 24 year old TV personality. But the world is what it is. We looked at a magazine and decided NOT. This is kind of what you get.

    If I did a book, you'd wait for the movie to come out.

    Jack Rickard

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  65. No Jack,
    A paper napkin of the basic maths :) Can't find those few gems. No matter.

    Your circuits I have already gleaned back from Google images.

    It was in consideration to save costs for core information. It's not your fault, its mine for not having notepad ready.

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  66. On a different note, anybody aware of the following qoute from a Tesla press release (I know plans can change).

    “Tesla’s current battery strategy incorporates proprietary packaging using cells from multiple battery suppliers. This new cell will also be compatible with other cell form factors to enable the continuation of Tesla’s strategy of using cells from multiple suppliers” [1]. Interesting don’t you think?

    Or is the above common knowledge?

    You all probably know this. According to my calculations the cell used in the Roadster is 2.3 AH in average (based on 56 KWh, and 3.6 V). The 3.1 AH cell with the spec sheet above is probably the same one going into the S [2,3]. The cell it replaces was 2.9 AH. A nominal improvement. But it seems that was not the cell used in the Roadster, so it’s a big step-up from 2.3 AH.





    [1] http://www.teslamotors.com/about/press/releases/tesla-and-panasonic-collaborate-develop-nextgeneration-battery-cell-technology

    [2] http://panasonic.co.jp/corp/news/official.data/data.dir/en091218-2/en091218-2.html

    [3] http://www.teslamotors.com/about/press/releases/panasonic-presents-first-electric-vehicle-battery-tesla

    Padraic McDonnell

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  67. This was an old and recycled quote and I'm sure they want it clear to Panasonic that they are not precisely captive, since they're using commodity batteries. But they've always used Panasonics and have had a good working relationship with them, to the point that Panasonic has invested $30 million in Tesla now.

    I posted the data sheet as a representative of their latest cells. They all have the same basic chemistry, but they are getting more AH into them all the time. It may be that the same battery pack is used with the 160 mile S model version as the 300 mile, but they use cells of larger capacity (and expense) in the same form factor, or that is how I would do it anyway.

    Jack RIckard

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  68. Thank you Jack.

    Of course you are right. I didn't consider the different packs.

    When the quote said: "This new cell will also be compatible with other cell form factors". This did not mean mixing the different cells in the same pack, which was nonsensical to me, and not an option I was sure. But if there is a 0.00001 % probability, I still wonder: “what if”. Compatibility with other cell form factors simply meant it was a 18560.

    I knew to take the quote with a pinch of salt, but I didn't know exactly what to make of it. Thank you for clearing that one up for me.

    I now think (nothing new to all of you) Tesla is going down this route to make the pack as cheap as possible -- period. Cheap to the point of it being disposable. They are not concerned with cycle life.

    Hope your DC to DC arrived. I would love to see a Top Gear style drag race between the two roadsters, and the Mini.

    Best

    Padaric

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  69. When I say different packs, I refer to capacity only.

    Padaric

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  70. No, I do not think Tesla did this to make the pack as cheap as possible, although that's certainly a legitimate design goal.

    They did it because these cells have a higher power to weight/volume ratio than the cells we use.

    Our cells are 10x longer cycle life, and we consequently can't go 244 miles on a single charge, and indeed some Tesla drivers have gone over 300 miles on a charge.

    FOr me, because of the expense of the cells, I prefer longer cycle life to the additional range. In practice, I rarely drive the "safe" 80 mile range of our cars except when specifically testing the cars. But I would much prefer to be able to just plug in my car, drive it, and have it last 10 years, than to have to buy a proprietary pack every 4 years or so.

    Jack Rickard

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  71. I almost agree Jack. You and others have established that Tesla is on a "quest for range". It goes without saying that they want to make the pack as cheap as possible, but their priorities are.

    1 Range

    2 price

    3 life

    That's for now.

    Once range is no longer an issue the priority will be:

    1 price

    2 life

    Leaving range aside for a moment, Tesla is more concerned about price, than life. That is my point. I do think that they are taking this route to reduce cost.

    But I concede they would have to be dirt cheap. Elon, though, seems to think that they will cost very little. Or at least that is the impression I get from interviews etc.

    Will cars on a second hand lot have new batteries? I can only speculate.

    Although life will come with advancement in batteries. Tesla by the end of this decade will primarily be concerned with cost. Although I didn't come to this conclusion scientifically, I think it's somewhat plausible


    Padraic

    P.S I would prefer longer life as well, but if the price is right, even considering long term options? And that's the point. How low can Tesla can get the price go?
    This is a simplistic look, I know its cheaper for me to pay $ 100 for a pair of Ecco shoes, than $ 50 for a cheaper brand.

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  72. Padraic:

    I think you're a little confused about price. Price is almost a non-term. Price for what?

    If I buy a $12,000 battery every week, that is expensive. If I buy one every 10 years, that is $1200 per year. Not expensive.

    So separating price from cycle life is kind of undefined. And they are clearly spending MORE on initial price than we are for batteries. There is no price advantage, in fact, kind of a huge penalty, to be using 6800 little 18650 cells. Worse, then they have to build these modules and do the cooling.

    We don't have to cool. We don't have to build modules. And the PRICE of our cells is less anyway. So PRICE is NOT any of their priorities.

    And I would posit that all this is WORSE YET given the cycle life of the cells. That's where it REALLY jumps the rail for me.

    I have to point out that TROJAN flooded lead acid cells are rated for 350 cycles. They appear to last longer than Tesla's cells. How little you drive it or how long that can be stretched out to is singularly disinteresting to me. These cells don't have the cycle life of good lead acid cells.

    And they cost MORE than our CALB prismatics. The only thing they get is RANGE and I can only conclude that RANGE was their only criteria.

    Jack Rickard

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  73. I mean price of Tesla’a pack, and in a very simplistic way. I am talking about the price of replacing a pack in 10 years time or so. Or replacing the cells if that is possible. Who knows maybe Tesla engineered the pack in such a way that cells modules can be swapped out.

    It gets complicated when you start thinking about different packs with different capacities and form factors. Although it’s not that complicated when I think about it. 300 cycles is poor.

    Anyway, all I have are what ifs, and ill thought out ideas. I am just trying put myself in the shoes of an Tesla owner, and imagining what will happen in the future with my pack, and the cost of replacement. I’m curious about what will happen in the secondhand market, particularly with cars more than ten years old.

    What happens when the battery is finished? Will a third party recycle it? There is no one in the U.S that recycles Lithium packs at the moment (I could be wrong). Will Tesla take the pack, dispose of the cells and reuse what can be used of the pack minus the cells? As I said, the price of the 18650 may become very cheap due to volume. Much less than a dollar per cell if that’s possible. How will trade-in and recycling affect the cost of batteries in the future? Will it aid the reduction in price?

    I’m not asking you to answer these questions Jack. YOU ARE RIGTH Jack (I am wrong, but maybe you understand my warped thinking after reading this), price for Tesla is not central, RANGE IS.

    Padraic

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  74. Tesla is working with Toxco in the US and Umicore in the EU to recycle the packs.

    JRP3

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