I applaud the initiative and direction this is going, but the ROI is too long at that cost. Well, at least here in Australia at that rate considering we don't have a Congress (or equiv) that would create rebate structures. Heck, we don't even have Transit lanes that allow hybrids the same lattitude as dual-occupant vehicles. But then again, perhaps the cost could be claimed somehow against tax as a business expense...

Isn't there some interdependency between the ICE and the generator that forces ICE to kick in above 47km/hr? So can this battery pack still work exclusively above that speed? My daily commute takes me on the freeway for 60% of the trip.

Regardless, love the direction this is going. I'll give it another 2 years and see where the price is then.

Why not just install these babies at the Toyota factory to cut the costs?

Oh yeah, the safety thing.

So why can Hymotion do it as an aftermarket and Toyota cannot? Is it because the battery pack is made up of a bunch of little bitty Li-Ion batteries?

The question people should be asking is if these upgraded batteries have any sort of warranty on them. Plunking down 9k for a battery that might die in a month is a risky bet.

:huh: I can't imagine why these would cost so much. No wonder they are dragging their feet in making them available to the public!

My fuel bill for 12 months driving, 25,000km per year is about 4.5 L/100km is around $1400US per year on current exchange rate and at a price if $1.40AU per litre. If I eliminated all of my petrol costs and ran my prius on electricity only, and even if I could buy electricity for free it would take me a fraction over 7 years to pay for the battery pack and conversion.

Now lets add to that the interest on the $10,000 at about 9% which is about the best rate I can find for a personal loan here and I'm down another $900 US each year then the cost of electricity, lets say $300 per year at a wild guess so now the battery pack and electricity will cost me $11,200 in the first year and I can pay off $1400 in saved fuel so I now owe $9,800! Going to take a while to pay this conversion off! Admitedly the price of petrol will increase but so might interest rates. I have also started with a petrol price 10c more than the current high in the weekly cycle.

Add to this the loss of load space and weight carrying capacity which is marginal with 4 people aboard, and the loss of the spare wheel well so no where to carry a spare, I think I'll let this one go.

I'm not saying this conversion isn't right for you, I'm just saying after forking out the readys for the car I cant justify the upgrade. Maybe next time.

Anyone who goes down this path, can you please let us all know how it goes.

If this is the Prius-Plus technology, those (lead-acid) batteries replace the spare tire. Even if they are using lithium, I suspect they have replaced the spare tire.

Why doesn't Toyota do this? Because most buyers don't want their spare tire sitting in the cargo area.

Once lithium batteries reach a price point where Toytota believes the market (i.e. average buyers) will pay the price, I think we may see a plug-in Prius from the factory.

However, note that the article is extremely misleading, because the Prius STILL cannot go over 42 mph in electric mode (34 mph in EV mode) or accelerate fast enough to keep up with traffic without running the gas engine. The plug-in Prius AT BEST gets half its energy from the grid while it burns gasoline for the other half.

The real solution is the Volt concept (which GM will never build, but somebody will) where the car operates at full specs on battery power for some distance (the farther the better) and then burns fuel after the batteries are depleted for longer trips. Even this will be an intermediate step, until fast-charging stations are available on the roads.

<div class='quotetop'>QUOTE(Bob64 @ Oct 20 2007, 09:10 PM) [snapback]528348[/snapback]</div>

That's a really good point. Here in Las Vegas, you are lucky if you can get 3 years on a regular car battery. The heat destroys them. I'd hate to pay $9k every 3 years to replace the battery.

While I agree with the ROI being long it seems funny coming from someone on a Prius board. If I was looking at ROI purely for fuel expenses, I would've bought a Yaris. I'm happy to see this technology and I will pay for the utility of funding my energy through local domestic sources rather than through foreign oil imports. If someone can provide this service to me, it is worth cash. Hence my willingness to embrace this technology. Like others I'll wait a little while until my warranty is gone however, once that is done, I'll definitely be throwing in whatever lithium solution is out in the market place. I think expecting an 8 year warranty out of such a solution is reasonable though.

Hi Daniel,

The developemental third generation Prius Plug-in mules are reported to go 62 mph on battery power. Which is good for 100 % off-highway travel around here, and probably 50 % on-highway travel (due to traffic).

I really like the Plug-in system the Boulder guys did. It is a whole battery system upgrade (they figured out all the packet data between the hybrid computers and the battery system). It is the only system I see as truely professionally engineered.

I also like the nano-safe batteries. They seem to be ready now. They do not have the enegy density of some of the others, but there is a good incremental improvement in energy density over NiMH and they have much better power at low temperatures. Besides having the capabilty for rapid charge (think long down-hill regeneration) and long calender life. If I was Toyota, I would license this technology quick, and come out with an evolutionary improved Prius.

Hi All,

The NiMH battery is not cheap either. The Reason we have inexpensive ($2500) NiMH battery susbsystems in our cars is that Toyota did the Henry Ford capitalist thing. They thought big, acted big, and got the cost down. They got a controlling share of PEVE (Panasonic EV batteries company) , and made them build the entire battery factory for vehicle batteries (both manufacture and recycling) from scracth. This factory has clean-room assembly and other high quality standards. The fact that the batteries are as reliable as they are is why they are as cheap as they are. Because not many people are going to buy cars that need new hybrid batteries on a random basis. Which the precision manufacture has avoided. So the quantiities of the build are sufficient to subdivide the overhead over a large number of battteries.

The same thing could happen with Li-Ion, but there is a missing thing before it can happen. CARB (Californian Air Resources Board) mandated vehicles resulted in engineering experience on the NiMH systems. That has not happned for Li-Ion. Which makes Li-Ion a much bigger engineering/economic gamble.

<div class='quotetop'>QUOTE(Spoid @ Oct 21 2007, 06:54 AM) [snapback]528429[/snapback]</div>

I'm not sure that's a valid comparison. In a non-hybrid car, the battery is stressed pretty badly b/c there is a huge current draw when cranking the engine. Of course, that stress is further exacerbated by heat (which increases the internal battery resistance). The Prius (and I would imagine Hymotion) batteries are 201V instead of 12V, meaning that if we assume the same starting power is required, the current needed is ~6% (12V/201V) which means much less stress. Even w/ terrible heat in LV, I don't think it would be stressed as nearly as badly as a regular car battery.

Anyhow, I'd like to see a smaller capacity and cheaper version that would only occupy the storage space above the tire for several reasons:
1) I don't think you really need 50 mi. capacity since most people with long commutes involve highway, where the battery range extender (BREM) can't help, and in fact would be detrimental due to the extra weight. Half that range (25 mi.) would probably be sufficient for the non-freeway portion of such a commute and lower the weight. Longer non-freeway commuters could probably deal with charging at work.
2) Cheaper means more people can afford them, more acceptance and would probably further drive down the price.
3) You can keep your spare. I even recall some thread where someone did a homebrew plug-in w/ a Prius and created a innovative mechanism for lifting the battery pack so you could access the spare (w/o breaking your back).
4) W/ lower capacity requirements you may be able to get away with NiMH which would make me feel safer since there isn't any sort of runaway thermal failure that you have with LiON. I'm sure this can be managed safely, but I'd sleep better if someone like Toyota who has a track record of safety and reliability, as well as a huge amount to lose if they are wrong, give their seal of approval on a LiON implementation. Plus NiMH is also cheaper.

<div class='quotetop'>QUOTE(Gadgetdad @ Oct 21 2007, 12:36 AM) [snapback]528369[/snapback]</div>

The 10k is for more than batteries, you're paying them for the r&d work to get it to work and all the programmers that had to figure out how to incorporate the system into the existing car.






<div class='quotetop'>QUOTE(Bob64 @ Oct 20 2007, 11:10 PM) [snapback]528348[/snapback]</div>

One would hope they would offer at cost replacement (no profit or installation fees) for early adopters.. but I don't see that anywhere in the literature