Andrew, My comments are interspersed below.
On Sunday, March 09, 2008 6:48 PM, Andrew Roddy wrote: > Charles, > > I guess I should elaborate regarding my comments; the following is just my > opinion and not an endorsement. > Technology in general, including battery technology, tends to become more > affordable over time as the initial investment in manufacturing equipment > and other capital investments are paid off; competition also has an > effect. That is a sweeping generalization that while true in many cases, is not true in all cases, and specifically, it is not true in the case we are talking about here of hand-assembling and tab-welding many thousands of small-format lithium cells into a vehicle-size pack. In fact quite the opposite, there are actually negative economies of scale associated with that. I am supposed to get my wife's computer back tomorrow from the technician who is repairing it, and he tells me that he has been able to recover most of the data on that computer, so maybe I can elaborate further on this tomorrow or Tuesday. > Commodity prices, including the cost of lithium tends to fluctuate over > time in tune with the business cycle, basic supply/demand. The price of the lithium laptop cells in the eBox and Tesla is nowhere near as sensitive to the price of lithium as it is to the price of cobalt. The price of cobalt is really the dominant factor here. > It's just my opinion, but I think commodities will cool down as we go > through a downturn in this business cycle. I would not necessarily agree with this. That is the kind of classical economics we were taught in the 70s and early 80s which no longer applies in the simple way that you state. The proof of that is the exact contradictory evidence to what you are saying that is staring us in the face today with the current economic situation we find ourselves in, where we are already in a business downturn and have been for at least the last quarter, yet some commodity prices are going through the roof, cobalt among them, while others, like nickel, have been declining. One very important reason for this seeming disconnect and paradigm shift from the classical economic models of the past that we were taught in school 25-30 years ago is that world commodity prices are no longer determined most prominently by supply and demand factors in the US economy, because the US economy is a slow growing economy that is no longer the world's dominant economy. The world's dominant economies are now those of China and India, representing 40% of the world's population, which have been growing at 10-12% for over 10 years now and continue to do so. Remember that commodity prices, like prices of all goods, are determined at the margin, and the margin is where the largest economic growth is, which are China and India. So world commodity prices, including cobalt, nickel, etc., are largely determined by the Chinese and Indian economies and the various demand for each of those specific commodities in those two countries, not by US business cycles, as was the case 30 years ago. Most of China's and India's economic growth is now internally generated and self-sustaining. Those two countries are no longer as dependent on exports to the US and Europe for their domestic economic growth as they were in the 1980s and 90s, when, in those days, if the US economy went into recession, it would also bring down the Chinese economy. Today, the current US economic recession may have the effect of knocking only a few points off of Chinese economic growth, bringing it down from, say, 12% to 10%, something like that. But that 10% Chinese growth rate is still an enormous amount of demand pressure on tight worldwide commodity supplies. > I think oil is the culprit behind what some are calling "stagflation". > The economy requires oil to function, but oil is becoming more expensive > even as business slows down. Yes, exactly my point; same phenomenon as I just explained above, coupled together with the fact that global oil production peaked in 2006 and is now in irreversible decline. > I think oil too may yet come down in price some in the short term, but > since the oil market is highly manipulated and the long term outlook is > for continued demand and reduced supply, I think it is likely that the > longer term outlook for oil is probably higher. > > It should also be noted that there are some lithium batteries that don't > use cobalt, such as lithium iron phosphate (LiFePO) batteries. Yes, but AC Propulsion engineers and management had a meeting last August where they specifically decided to forgo the opportunity to use LiFePO4 batteries in the future and designed their BMS in a way that cannot handle LiFePO4 cells. Prominent electrical engineers in the EV business think this was a serious mistake that showed very poor judgment on ACP's part, especially because AC Propulsion has already had a battery pack fire with one of their 18650 LiCoO2 packs. > We have good battery technologies today, and there will be even better > battery technologies as we progress. I agree. > The future looks bright for batteries and other energy storage > technologies, not so bright for oil. I agree. > Regarding the calendar life of lithium batteries, they are affected by > charge, depth of discharge and temperature, so the calendar life will vary > some. True. Ambient temperature, and thus climate, is the dominant factor. The other things you mention are also factors. > The point I wanted to make is AC Propulsion's battery management and > thermal management system is probably one of the most advanced > systems if not the most advanced system available, Not infallible, as their battery pack fire showed, but yes, ACP's is as good as it gets at the moment and is state of the art for that type of LiCoO2 chemistry, if one insists on using it, against the advice and warnings of all the major automakers, as well as the government's top battery scientists at Sandia National Labs, that Tesla's and ACP's batteries are not safe. > so I expect my battery pack will last as > long as it potentially could. Let's hope so. You will be one of the earliest test cases for ACP's LiCoO2 pack. > I still think 3 years is a bit on the short end; I think battery testing > tends to be a bit aggressive. > I'd like to see some real world testing results for lithium batteries. Real world testing, meaning on the road in EVs (as opposed to just on the bench in a lab), going back over a decade now, has shown lithium batteries to have a calendar life of 3-5 years. Charles > Andrew > > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Charles Whalen > Sent: Sunday, March 09, 2008 4:15 PM > To: Florida EAA > Subject: Re: [FLEAA] NiMh PATENT > > I would like to make some comments in response to both Al Lococo's and > Andrew Roddy's respective posts below. > > First, let me just point out that large-format (85-100Ah) NiMH batteries > have a well-established and proven calendar life of over 10 years and > 200,000 miles in EVs. > > Al wrote: > >> Lithium Ion batteries have excellent power to weight and size ratios for >> electic vehicles. > > Al, I'm not sure if you meant "power" or "energy". If you meant "power", > it > depends on what lithium batteries you are talking about. The power > density > of the 18650 LiCoO2 laptop cells used in the Tesla and the eBox is not all > that great. A123 and Kokam, for instance, have much higher power density > than those used in the eBox and Tesla. > > I'm going to assume that maybe you meant "energy", or at least that's what > I'll discuss and how I'll frame the comparison here. > > The energy-to-weight and energy-to-size ratios, which I will refer to as > gravimetric energy density and volumetric energy density, respectively, > are > indeed much greater for the 18650 LiCoO2 laptop *cells* used in the Tesla > and eBox versus large-format NiMH, but that is *only* at the *cell* level > and does not hold true at the pack level. At the *cell* level, the 18650 > LiCoO2 laptop cells are about twice as energy dense, gravimetrically, as > NiMH, at around 120 Wh/kg for the 18650 LiCoO2 cells vs. 60 Wh/kg for > NiMH. > (ACP and Tesla had actually previously used even higher energy density > LiCoO2 18650 cells, up to 140-160 Wh/kg, but were forced to downsize to > safer, lower capacity cells, with thicker separtors, etc., due to > significant concerns about the serious thermal runaway/combustability > safety > hazard with those batteries.) But again, this is all at the cell level > that > we are talking about with those 18650 LiCoO2 laptop cells. Andrew > correctly > referred to ACP's (same as Tesla's by the way) substantial safety measures > in their sophisticated, triply-redundant BMS, at the individual *cell* > level, water-cooled thermal management system (TMS), etc. One thing > Andrew > didn't mention is that each of those individual 5,088 cells in the eBox > and > 6,831 cells in the Tesla is encased in its own thick, heavy steel > sarcophagus, in order to contain and isolate any thermal runaway and > fire/explosion in that cell and prevent a chain-reaction spreading to > other > cells and the rest of the pack. Well, what do you think all those thick, > heavy steel casings around each individual cell, plus all of that complex, > sophisticated electronic circuitry for each individual cell, plus all of > those liquid cooling jackets and piping, do to the erstwhile gravimetric > and > volumetric energy density advantage of 18650 LiCoO2 laptop cells, at the > *cell* level, over NiMH, when you balloon all of that up to the pack > level, > with all of that excess volume and weight for all of that required BOS > safety gear? ... Hhhhmmm, yeah, you guessed it, you lose most of that > energy density advantage of lithium over NiMH and bring the two much > closer > together. > > The advantage of NiMH is that it is so robust that it doesn't even need a > battery *management* system in the sense that we normally think of that > term > for lithium batteries, i.e. individual cell protection circuits, voltage > clampers, etc. None of that is necessary nor used for NiMH battery packs > in > EVs like the RAV4-EV and Vectrix. In fact there is absolutely no > electronic > circuitry at all at the cell level. There is only a battery *monitoring* > system (as opposed to a battery *management* system) at the *module* > level. > Basically all this consists of is a simple temperature probe and voltage > monitor on each module with communications signaling back to the > controller > and charger, telling the charger when to shut off, etc. Very basic and > simple, costing only a few hundred dollars per vehicle, as opposed to over > $10,000 in many cases for a lithium battery pack BMS and TMS. NiMH can > take > and absorb a huge amount of overcharge, much more so than sealed > lead-acid, > for instance, more like similar to flooded lead-acid. In fact, NiMH is > very > similar to flooded lead-acid in the way that an equalization charge is run > about once a month -- at 3A for around 2 hours. If you don't allow the > equalization charge to run when the charge controller calls for it once a > month and let it go, say, 6 months without equalizing, then when the > equalization charge eventually runs, it will do so for about 6 hours. > ... Yeah, 6 hours of putting overcharge into those NiMH batteries. No > problem. > > Andrew wrote: > >> I believe the replacement cost for the eBox battery pack today would be >> approximately $25,000, over time the price should go down. > > Quite to contrary, the price of these LiCoO2 battery packs in the eBox and > Tesla are going *up*, not down, while the price of NiMH battery packs has > been falling. In the last year, the price of nickel has fallen from > $54,000/ton to $30,000/ton today, whereas the price of cobalt has gone in > the opposite direction, doubling in price from $26/lb. to now over $52/lb. > This fact, as well as other problems with Tesla's battery pack, is the > real > reason for Tesla's continuing delays (with the transmission problem excuse > being largely a smoke-screen). The cost of Tesla's battery pack has > increased so much that they are now underwater on the $100,000 sales price > of the Signature-100 cars that they have pre-sold and must now absorb a > loss > on those first 100 cars due to the rising cost of the battery pack. > > On the calendar life issue of lithium batteries, it is a well established > fact that it is no more than 3 or 4 years. Under various NDAs, I have > seen > a number of confidential internal company calendar life studies of lithium > battery manufacturers which document this scientifically. Every single > battery manufacturer CEO I've spoken with, and I've spoken with a number > of > them, admits this privately. Some have even admitted this publicly, on > the > record. The well established empirical record of on-road field experience > with lithium-powered EVs, of both hobbyists and the big automakers, going > back over a decade now, shows that these battery packs lose 10-20% of > their > capacity per year in a hot climate like Florida and 5-10% of their > capacity > per year in a cold, northern climate. This corresponds to the scientific > lab studies of accelerated calendar testing that all the lithium battery > manufacturers have done but most don't like to talk about publicly and > some > won't even admit to doing. > > Tesla's senior executives have admitted to at least some of their > customers > (from my communications with them) that they expect the battery pack's > calendar life to be about 4 years and definitely need replacing by 4 or 5 > years. I give Tesla a lot of credit for their honesty, integrity, and > business ethics. > > Lithium battery manufacturers have all been aware of the serious calendar > life problem for well over 10 years now and have been intensely working on > trying to solve this problem for over 10 years, but little progress has > been > made to date. Despite that, I nevertheless remain hopeful that some very > slow, gradual progress is starting to be made in this area and that within > 5 > years we should have some pretty good lithium batteries that should > hopefully last 10 years in an EV. > > I would agree that we need both NiMH and lithium batteries. The more the > better. It is people like Andrew Roddy and Cliff Rassweiler who are > stepping up to the plate to be pioneering early adopters of lithium > battery > technology that is making this continuing progress possible, which will > benefit all of us being able to get much better, longer-lived lithium > battery packs in EVs in the future. Without people like Andrew and Cliff > paving the way and helping to pay the development costs, none of this > would > happen. We owe them both a debt of gratitude. > > Best regards, > > Charles Whalen > Delray Beach, FL _______________________________________________ Florida EAA mailing list [email protected] http://www.floridaeaa.org
