Developing Battery Replacement Infrastructure For Electric Cars 369
FathomIT sends in a NY Times profile of Shai Agassi, owner of a company named Better Place, who is working to build the infrastructure to support large numbers of small-scale charging spots for electric cars, as well as fast, automated battery swap stations.
"The robot — a squat platform that moves on four dinner-plate-size white wheels — scuttled back and forth along a 20-foot-long set of metal rails. At one end of the rails, a huge blue battery, the size of a large suitcase, sat suspended in a frame. As we watched, the robot zipped up to the battery, made a nearly inaudible click, and pulled the battery downward. It ferried the battery over to the other end of the rails, dropped it off, picked up a new battery, hissed back over to the frame and, in one deft movement, snapped the new battery in the place of the old one. The total time: 45 seconds."
Re:Interesting... (Score:5, Informative)
Re:Interesting... (Score:5, Informative)
free battery replacement (Score:4, Informative)
The next item is battery theft. You might laugh and say they're too bulky, but battery theft has become a serious problem here. The race between locks and thieves was altered by the presence of a widely adopted new design, so thieves just started pulling batteries out of electric bikes and taking those instead (about a third of the bike's cost to replace). Now, there's a new cage add-on thing that you can buy to enclose your battery in a protective shell. Crazy. Point is, I've been riding around on the same battery for a while, it's time to change, and I wish there was a replacement depot I could dump my old battery on and get a fresh new one for free.
Re:Standard values not applicable here. (Score:5, Informative)
Does anyone know if battery testing technology is sufficiently advanced for this to be feasible?
Shouldn't be too hard. Apply a voltmeter and then draw a heavy current on a separate circuit over a set time. That should a reasonable indication of the basic quality of the battery. Same way you test a car battery now. Apply voltmeter, crank motor. If the voltage drops fast, the battery is toast.
Re:Standard values not applicable here. (Score:3, Informative)
Who picks up the tab for a dead battery? The owner or the 'fuel' vendor?
In Agassi's plan, the "vendor" owns the batteries. Whenever you "fill up" your car by swapping them out, you're basically renting the batteries for the duration.
Re:Standard values not applicable here. (Score:5, Informative)
Plus, the battery packs are not the same as ordinary batteries. There are brains built into them to monitor health, balance cells, control charging and discharging, and generally prevent degradation in the first place.
time will tell if your concern is borne out in practice, but I personally am not too concerned.
Re:it was my idea (Score:5, Informative)
No indeed. It's called a staging-post. It's where a stagecoach would stop, and rather than waiting until the horses were fed and watered and well rested, they'd simply drop off the horses there and take fresh horses for the next stage of their journey.
Re:Standard values not applicable here. (Score:1, Informative)
Google "bad gasoline"...
The charge/swap station will need to check the status of the battery. Even your laptop pack knows how many watt-hours it had on its last full discharge.
Lease the battery and own the car, rather than owning both sounds best to me.
Re:Why bother? (Score:4, Informative)
Actually, there are battery designs where the container can be reused an "unlimited" number of times. One such design is the vanadium redox battery [wikipedia.org]. Unfortunately, they do not begin to compare to lithium ion batteries in terms of energy density. However, if this tech or similar tech could be improved to the point where you could build an auto-sized vehicle that could get 150-200 miles per charge, then it's not hard to imagine a world where gas stations have been replaced by "electolyte swap facilities" where the discharged battery is "recharged" quickly by draining and replacing the electrolyte solutions. The same car could also be recharged by mains power at night.
Why not avoid batteries altogether? (Score:4, Informative)
1. batteries in general are a poor solution because of several things:
a. poor energy density compared to chemical energy
b. battery production is inherently filthy, and quite bad for the environment on its own
c. charge times are awful. people like the model of gas. several hours to deplete the energy, but you can replenish it at a filling station in under 5 minutes, assuming you don't have a semi or something.
d. even the best batteries are quite heavy, and thus make the car less efficient.
happily, there is a very good solution. ultracapacitors, sometimes known as ultracaps. they hold more than batteries, weigh an order of magnitude less (sometimes 2 orders) and can be charged, quite literally, in seconds. (not with plugs at your house... you'd have to go to a filling station that can generate a LOT of current to recharge this fast. you could still trickle charge at home in the evening, but for a quick fillup, you'd need a power station). ultracaps are not dirtier to make than LiON batteries. ultracaps have good staying power, last virtually forever (no practical limit on charge cycles) and hold much more than a battery of similar size, and orders of magnitude more than a battery of the same weight.
Re:Not reported != not happening (Score:3, Informative)
Re:Standard values not applicable here. (Score:4, Informative)
Better Place Business Model [betterplace.com]
Re:RTG's, baby... (Score:3, Informative)
Re:Not reported != not happening (Score:4, Informative)
I am familiar with this recall because my wife has a 2007 Prius, and I would not buy a Prius until the bugs had been worked out of the system. This was one of the two noteworthy bugs.
This problem was contamination or corrosion or something on the positive terminal resulting in increased resistance. The engine computer notes the increased internal resistance of the pack, says WTF, and sets a code. There is much debate as to the proper fix, with some dealerships swapping out the battery pack entirely, and some expending considerable labor hours completely disassembling the pack, cleaning the terminal, and reinstalling. In some countries they all swapped, in some they all rebuilt, probably depending entirely on the cost of local labor vs the cost of factory new.
Also, I would take a wild guess that Japan told them it would take 15 minutes labor each, then the dealers found out it took 3 hours, and the end result is the first few people got the reassemble procedure and PO'd techs and the last few people all got the swap procedure. Perhaps if you make an appointment they'll assume you've got the time to do the reassemble procedure, vs if you're just there for an oil change you'll get the swap procedure.
There is quite a bit of info on this on Google. But don't confuse it with the recall around 03, where the engine computer shut down the engine too quickly, so it would stall on the highway occasionally. That was a simple firmware flash.
Other than that, a remarkably recall free vehicle, at least compared to domestic models.
Also wear and tear weasel words do not apply until after 100K or 10 years whichever comes first.
Finally since there is no market for the batteries, there is no 3rd party market for the batteries, thus the ridiculous $3K cost is the usual dealer and OEM markup. Just like you can pay $25 for an oil drain plug at the dealer, or $1 at autozone. I am sure that in a decade you'll be able to buy a prius battery from batteries plus for perhaps $300. If I recall correctly, its just a huge array of NiMH D cells, not anything exotic at all.
Re:Interesting... (Score:2, Informative)
I'm a little confused by your post... Your parent poster linked to topics that indicated cars who have driven 240,000 and 300,000 miles each without any problems to the battery. The second article ,http://jcwinnie.biz/wordpress/?p=3579 [jcwinnie.biz], said:
"Only two of our 182 hybrid battery packs have had to be replaced during the years hybrids have been a part of the city's taxi fleets," Gillespie said. "One was replaced under warranty and the other was driver error." The taxis in the city average 90,000 miles a year.
So maybe you could clarify your post for me because it is a little confusing on what you said against the data presented.
Re:Why bother? (Score:4, Informative)
Actually, vanadium redox *can't* be improved to that point. Take the molecular weight of the relevant ions and the reaction potential, and that will give you how many electrons at how many volts a kilogram of the relevant chemicals can produce, which is just a units conversion away from joules or watt-hours per kg. Add even a modest allowance for stuff to dissolve those ions in and acidify the solution, and it doesn't stand up to LiIon for capacity.
However, capacity per kg isn't the only metric of interest -- cost and ease of refueling / recharging are both quite relevant. The lack of aging problems with the electrolyte is also useful. I suspect vanadium redox will never see widespread use outside of stationary load-leveling applications, but there's no guarantee of that.
The other major tech to watch, of course, is EEStor's capacitors. They claim energy densities similar to current LiIon tech with a number of improved capabilities, but last I heard still hadn't (publicly) demonstrated a working prototype.
Re:RTG's, baby... (Score:3, Informative)
RTG is the only logical source of power for a tractor-trailer.
Very true, if you want a tractor-trailer with a maximum speed of a few feet per minute but runs decades without refueling.
RTGs produce very little power for a given size/mass. Their advantage is that they can keep doing it for a long time.
Re:Why not avoid batteries altogether? (Score:5, Informative)
happily, there is a very good solution. ultracapacitors, sometimes known as ultracaps. they hold more than batteries, weigh an order of magnitude less (sometimes 2 orders)
That's pure, unadulterated BS!
The best ultracaps have less than 10% of the energy density of a rechargeable battery: 30Wh/kg as compared to 300Wh/kg for LiIon and 370Wh/kg for zinc-air. To put things in perspective, the gasoline energy density is 12500Wh/kg, 30 times better than the best commercially available batteries...
Ultracapacitors cannot even begin to compete with batteries as the primary energy storage, their role is limited to storing regenerated energy (e.g. from braking).
Re:RTG's, baby... (Score:3, Informative)
Re:Or you could just charge it ( no seriously ) (Score:3, Informative)
"The required current is then 318 Ampere."
Most houses in the US have electrical service of 200A or less.
Re:Why not avoid batteries altogether? (Score:4, Informative)
Re:Standard values not applicable here. (Score:3, Informative)
Unfortunately, there is still no reliable method for assessing the state of a battery, only whether the battery is completely ruined. The various electronic circuits built into laptop batteries are, sadly, a testament to this. The only accurate methods for assessing the state of chemical batteries are still, sadly, destructive.
Re:Not reported != not happening (Score:3, Informative)
Also wear and tear weasel words do not apply until after 100K or 10 years whichever comes first.
Actually, if you look at most warranties they put those weasle words into the agreement, something along the lines of "Except for regular wear and tear", effectively making the warranty a "catastrophic failure" deal instead of the "if it breaks we fix it" agreement that covers everything. Also, it is the dealer who determines what is a failure and what is "wear and tear", which means they rarely pay out under the warranty if it is anything but completely obvious that the part should not have broken under the circumstances. There are warranties that cover everything, but they are over and above the "10 year, 100k mile" warranty companies like to boast about. They are usually called service agreements (because they imply/require regular checkups for oil changes and replacement of covered wear and tear items), rather than warranties, and they tend to cost a lot.
Re:Why bother? (Score:3, Informative)
Actually, you don't have to make it handle the full range. If you only handle the 30V-100V range, thanks to E=CV^2 you're not using the last 9% of the energy, meaning you get to use 91% of the capacity. More realistically, you could design your power electronics to provide full motor power at 30V, but keep working at reduced output power (they're mostly limited by max voltage and max current, so at 15V they can provide half the max power as at 30V). Then, when your car's battery gauge starts showing E, your car keeps running but you can't get as much acceleration from it.
Trading off peak acceleration in the bottom 9% capacity for cheaper and more efficient power electronics makes a great deal of sense to me. A 3:1 input voltage range is at the high end for normal DC-DC converters, but it's hardly unheard of. If there was a reason to, you could make it handle a wider range than that, but I suspect in practice a trade like this will be made.
(FYI: EEStor's capacitors actually run at a rather high voltage, like 3500V peak, but the issues stay exactly the same.)