Battery Management Technology Could Boost EV Performance
Researchers from the University of California, San Diego have teamed with Bosch and Cobasys to create a battery management system that would enable EV batteries to be charged to their limits. (Source: UCSD)
Definitely a much-needed technology development, but a commercial version in three to four years? That seems a bit long given how fast this market needs to move. Is it the algorthim the cause for such a protracted commercialization schedule or are there other factors impeding its release?
Beth, that's an important point. For one thing, this is a research project. I have worked on DARPA projects in the past. If it is DARPA it is, by definition, more basic research and this probably further out. Frankly, this has not been done and the researchers are speculating at this point. That said, they might well make it work. On the other hand, in three to four years, the landscape may be completely different.
Timing is also important in light of events from yesterday. A123 Systems filed for bankruptcy protection. One of the hot battery makers in the US, funded with massive amounts of Federal money, A123 looked like a winner. One of the big problems they had was that the demand for electric vehicles has not materialized. Another area I noticed they were interested in was utility storage. They were a lithium ion maker, and I don't know how useful that technology would be at that scale. It was the automotive sector, though, that hurt them. Their assets are being picked up by Johnson Controls, who is a large supplier to the automotive sector. This is a technology that needs lots more work.
Thanks for the that context, Naperlou. I hadn't heard about A123 Systems and that's a huge ding for the battery industry and for the momentum around EVs. They were definitely touted as one of the pioneers with promising technology so it's disheartening to see them ending up in bankruptcy protection. Again, it speaks to the time-to-market pressures on startups in the industry, which are caught between needing to hammer out the very real technical and development challenges associated with this technology, but also feeling the heat from investors who want/need to see returns from a commercialized product.
Good point about A123, naperlou. The weak electric car market was their undoing. And more are sure to follow. The "last men standing" in the saturated EV battery market will be those who have enough capital to hang on until vehicle sales start rising. As you point out, A123 struggled, even with government funding.
As Naperlou pointed out, Beth, this is a research project. Given that, if they could productize this in three to four years (as they hope), it would be a major success. In truth, it's a tricky undertaking. In essence, they are squeezing more out of a battery by operating it to its very limits, which can be dangerous to the life of the battery. Today's electric cars typically don't come close to the operating limits of their batteries because automakers don't want to "brick" them (consider the guy who bricked his Tesla battery early this year and was told a replacement would cost $40,000). To make this work, they need to understand every specific battery chemistry very, very thoroughly.
Nearly 20 years ago I dealt with a unique charging algorithm. We'd take a 1Amp/hr battery (suggested charge rate of 100mA peak) and inject 2.5Amp into the unit for roughly 0.5sec. This was followed by multiple 10Amp discharge pulses on the order of 1mSec in duration. This cycle was repeated continuously and formed the basis for the charging process. The result was a 20 minute time required to charge a fully discharged battery to 100% capacity. In addition the battery was cool to the touch upon completion of the charging cycle resulting in the electroytes were not being stressed due to excess heat. Batteries could be cycled through the discharge and charging process for more than 2000 charge cycles prior to showing a 10% reduction in capacity. This algorithm was implemented on nickel-cadnium or lead acid batteries and to a lesser extent nickel metal hydride batteries. The discharge pulses acted to redistribute the charged particles within the electrolyte reducing resistance. Efficiency in a normal charging process typically drops off in a matter seconds after the charge current is initiated. Here the discharge pulses act to "reset" the operating point on the efficiency curve to a much higher level thus allowing for the rapid charging process at a much higher efficiency. Less heat and longer life! Haven't seen or heard of the technology since then.
I am working on a 6KW battery charger design driven by a small wind turbine for use in charging 1000~2000 AHr 48 volt batteries as used in mobile phone (or cellular phones!) base stations. Wind is much cheaper than diesel, at least when you have some wind.
I have seen many apocryphal references to the process you describe yet many of the battery manufacturers (mainly lead acid) have either never heard about the process or say that it is a load of bunk ( or some such comment; usually far less polite!)
I have as yet to find someone who practised the "black art"; that is until now.
Charging batteries from the wind is a precarious affair as usually there is either far too much energy or almost no energy available with sporadic availability (the usual state of affairs) somewhere in between. It is this latter region that you need to "grab" whatever energy is going and make best use of it without shortening the life of the battery. The process you describe has great potential (excuse the pun) to increase the efficiency and reduce the charging time in the "sporadic region". At 2000AHr the currents flowing in the system could have spectacular results if we get it wrong.
I would be very interested in any information or experience you could pass my way about this "pulse charging method"
Patent 4,829,225 gives a quick overview. Company holding patent is still in business, "Advanced Charger Technology", based out of Atlanta but looks to be focused primarily on radio batteries. In the past they had worked on Lead acid batteries as the patent mentions.
Great idea, but where is the charging infrastructure coming from to enable these potential charge rates?
There's enough grumbling about the costs associated with putting in a 220V circuit in EV owners' garages, and the current rate of charge for existing technology is already capable of exceeding that source.
Even at an EV "filling station" the power feed required would be pretty remarkable. Which means even more expense and complications to create a point of load energy supply for them.
How about getting the cost of the batteries down first?
One of the possibilities that might occur from this effort is discovery of technology unconsidered at this time or previously. R&D sometimes gives us much needed but unforeseen new products. I certainly agree that four to five years is time enough for a changing landscape--politically and economically but I suspect the overall effort will yield value added.
I agree that that other discoveries could come from this, bonjengr. This, in itself, was a little bit of a surprise discovery. Virtually all reserachers have focused on changes in chemistry as a means of boosting energy and cutting cost. I'm encouraged by it, but I do wonder how the general conservativeness of auto companies will play into it. Auto companies are very frightened by the idea of warranty problems and they often prefer to build in big factors of safety to head off potential issues. The idea of operating a battery so close to its limits could be scary for them.
There is an unfortunate problem that is being overlooked in many projections, which is the reduction in distance per charge due to running automotive air conditioning. No matter what the battery type, the vehicle AC system will cut available miles by about a third, possibly a lot more, since the cooling will be running even when the vehicle is stopped and not consuming any power for driving motors. Probably that will kill the EVs deader than any other challenge. And it is a pity, since at one time it was a luxury that most folks did without, and got by quite well.
That's an interesting point. The first time I worked on a climate control system we had an auto mock-up and I was shocked to see this enormous 7.5HP motor that was used to drive the relatively small AC compressor with the tiny 5 inch pulley.
The large power requirement of vehicle AC is exactly my point. Back in the mid-1970's era the specified chassis dynomometer road load for a medium sized car was about 15 HP, as I recall. The road load for a current vehicle should be a bit less, since there have been quite a few advances in reducing drag since then. But the thinner and lighter vehicles probably have less insulation, and so would need even more heat removal power.
So what would serve best is a bit more truth about the actual vehicle range with the accessories in use. Just as published gasoline mileage is based on ideal conditions, and actual conditions produce lower mileage, the specter of range halving due to AC use should be made known. It could easily be the show-stopper that alters the whole picture. Is there any published information that anybody has seen?
The posting that seems to be in response to my comments about the airconditioning load is so far off the topic that I wonder if it was supposed to be in a different publication. Not really related at all. "Cheap Nike shoes"??? Not even sort of close.
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