REPORT: Toyota secretly tested lithium-ion Priuses for three years
by Sebastian Blanco on Sep 15th 2009 at 8:57AM 
2010 Toyota Prius - Click above for high-res image gallery
Details are scarce, but it turns out that Toyota has been testing Priuses with lithium-ion batteries in them for years. Not many vehicles were involved – Bloomberg says only 126 such Priuses were on the roads in U.S., Japan and Europe – but the tests began in 2006. Toyota spokeswoman Jana Hartline confirmed that the tests ended last month. A Toyota battery engineer said that the li-ion packs gave fuel economy a small boost, but that, unsurprisingly, the company still prefers NiMH packs in the production models. Either way, Toyota says that the "durability, stability and safety are assured" when it comes to li-ion batteries. One analyst said that Toyota's tests, "appear to be among the most thorough done by companies planning to introduce [li-ion] batteries."
These Priuses are not the plug-in Priuses that are getting a very public testing around the world. We wonder what sorts of secrets are happening with that program.
Gallery: 2010 Toyota Prius
[Source: Bloomberg]
Reader Comments (Page 1 of 1)
Nick From Montreal 9:17AM (9/15/2009)
Back in May, a Prius upgrade shop managed to get 70mph just by adding a bigger battery pack and modifying the EV mode management software. One thing they remarked was that the Prius seems to have been designed to be able to be a full EV, which led them to predict that Toyota would one day make the same "modifications".
As I said before, Toyota is ready for EVs -- its just that they want to milk the Prius Hybrid as long as they can. Once they start having some real competition, they'll release a pure EV Prius and regain the green car top spot.
Diabolical, yes, but very financially astute.
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Boyprodigy1 5:37PM (9/15/2009)
They still have yet to answer nissan...
Mark Kiernan 9:58AM (9/15/2009)
If they could get 40+ miles in EV they will beat the Volt. This is because it will no doubt be cheaper than the volt and second it has Toyota Prius brand quality.
I am very doubtful they could get anything near 40 mile in EV though, as they have to lug around a heavy ICE.
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nrb 10:44AM (9/15/2009)
"This is because it will no doubt be cheaper than the volt "
Where'd you pull that from?
Chris M 3:17AM (9/16/2009)
I doubt a Plug-in Prius would be cheaper than the Volt if it had a 40 mile EV range, that would mean packing a Volt sized battery. Remember, the Volt also has to lug around an IC engine. It is much more likely a Plug-in Prius would use a smaller battery than the Volt, with less EV range, and that would result in a lower cost PHEV.
Yanquetino 10:02AM (9/15/2009)
Yup. No surprise here. I've said all along that Toyoda, et.al., play their cards very close to their chest. They are also masters at bluffing to put the competition off guard. Wanna bet that they have been testing a pure EV Prius for years? And that they'll "magically" reveal it about the time that Nissan and Mitsu start taking orders? Time will tell.
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Sebastian 11:59AM (9/15/2009)
If they do, I'll be so *not* surprised
Bobmarley 11:17AM (9/18/2009)
kind of a late reply but....your exactly right. Unfortunately GM is about the opposite with their "cards" as we see them advertising/bluffing about future models which is a good indicator of their current state
ivor.pdx 11:58PM (9/23/2009)
Toyota management no doubt have read, and *practice* Sun Tzu's 'The Art of War', while Detroit executives use books like that to impressively pad their bookcases at the expense of their companies. Big difference....
PabloKoh 10:08AM (9/15/2009)
Seems Toyota has some good engineers that can put together systems with diverse foundations to be ready for a seamless changeover no matter what energies are being used at the time. I have even heard the computers and sensors in the Prius have the ability to accommodate E-100 ethanol like a Brazilian flex-fuel car with no modifications. Of course the factory will not tell you ethanol or strictly EV is even possible, and of course they will void your warranty.
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nrb 10:45AM (9/15/2009)
If everyone assumes you're doing it, is it really a secret?
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Yanquetino 11:44AM (9/15/2009)
Nope: it's not.
However... when it comes to the consumer market, we EV advocates who frequent this forum are a far, far, far cry from "everyone." And Toyota knows this.
3PeaceSweet 11:46AM (9/15/2009)
There's no reason you couldn't keep the NiMH battery for the hybrid drive train then add some Li-ion to power the all electric range in 2.5 kWh (~7-10 mile) packages
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wvuquentin 5:21PM (9/15/2009)
I have no doubt that the Prius could be made to run 40 miles on battery power alone. The issue is cost. In order to go that far on battery alone, you need a significant amount of batteries and that adds significant cost. That is the only reason the Volt will be as expensive as it is. Until Toyota can show some solid gain in fuel economy without too significant increase in cost, I don't think we'll see an extended range EV Prius or Li-ion Prius. It is all a game of diminishing returns when you consider the add'l cost and weight of batteries for the marginal increase in range.
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skierpage 7:25PM (9/15/2009)
Well, duh, obviously more batteries cost more. But Toyota risks marginalization as plug-in cars take off. "You have a car with a battery pack but you *can't* plug it in as the cheapest way to travel the first few miles??!"
We are one war/price gouge/oil spill/greenhouse gas alarm away from a much greater proportion of the public saying "F*** the oil companies, I'd rather recharge at home." It's not an economic decision. Hence the oil companies' relentless revolting greenwashing campaigns.
Dustin 2:54AM (9/16/2009)
Don't you think this kind of stuff happens all the time? No major auto company has an electric vehicle or PHEV, yet look how many showed up at the Frankfurt auto show. Do you think these were slapped together last week? No, all manufacturers have been developing and testing these "new" technologies for years, even decades.
The only story here is that Toyota's done 3 years of thorough testing of Li-Ion batteries and still prefer NiMH.
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Chris M 3:27AM (9/16/2009)
The preference for NiMH may lie with Toyota having over 14 years of experience with it, its reliability, and its current low cost. However, the price per Kwh stored for LiIon batteries is dropping, and is now close to the cost for NiMH. It would not be at all surprising if LiIon ends up being much cheaper in just a few year, if that happens we could see Toyota shift over rather quickly. Of course, the advantages of lower weight may result in LiIon being used for certain high end high performance hybrids, even with a higher cost.
Toyota is gaining experience with LiIon, preparing for the future.
mesama 9:20AM (9/16/2009)
Fundamentally, the Prius is still a parallel hybrid. They cannot transition it into an EV just be increasing the battery size. The Volt, on the other hand, is a series hybrid. It is basically an EV with a generator. So it can seamlessly transition into an EV just by dropping the generator.
Although they have the short term advantage, the Prius (and similar hybrids) will quickly run into their dead-end as expectations for all-electric range grow. At that point they will have to shift to the new structure, where the electric motors drive the wheels; that is not a natural continuation of their current work.
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Aaron 5:42PM (9/16/2009)
Isn't Hyundai going to release a Li-ion (polymer?) next year?
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brianhe 6:44PM (9/16/2009)
I urge you to check out... byplug.com ......
.. ...there you will find the articles about 179 MPG Prius conversions that go 70MPH and run in 'blended mode'....I have personally met Kim Adelman, been to his shop and seen and sat in the car. It's real and independently tested!...
His conversions with Ewert Energy are way ahead of Toyota and their near next few years - future releases...read about it.
I own an 08 Prius...The future is here..
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