If the cost of these batteries can be reduced this might be an option worth considering when the original Prius batteries need to be replaced.

This also might also give Toyota a second source for NiMH batteries without the restricts imposed by Cobasys.

why wait for Toyota to do it

Says a guy who just told us that solar is not afforable because it has a multi-year payback period.

But hey - drop $20K on a Prius, another $10-15K on an aftermarket plug-in kit, and void your Toyota warranty. Great idea!

We have seen alot of PHEV companies make great claims then not deliver. The trail of dead or non performing companies is at least three now. (non performing to me is saying cars will be publicly available in 2006 then not even having any done for the general public in 2007)

This offer sounds great but now I am skeptical. I would drive hundreds of miles for installation and gladly pay $7,000 for a 25 mile range and a safe system.

You could always get a used Prius (warranty already expired or close to it) for less money and put the battery in it, If the battery outlasts the car, take it out and put it in another. The car itself will last longer when the engine gets less use.

Okay, so now we have $6000-7000 USD for 6.4kwh, or roughly $1000/kwh for 2000 cycles, meaning $1000 /2000 kwh battery amortization cost, or 50 cents/kwh. Adding to that 15 cents/kwh utility rate, or 65 cents/kwh overall energy cost, and since a Prius is capable of ~250wh/mi, or 4mi/kwh, so the energy cost per mile is 65 cents/ 4mi = 16 cents/mi.

A gasoline Prius costs ~280 cents /50 mi (@ 50 mpg), or a fuel cost of 280/50 = 5.6 cents/mi. If this Prius is run on potentially-renewable natural gas costing 1/2 that of gasoline per BTU, then the cost/mi is only 2.8 cents/mi.

Still, very encouraging and exciting development, given such a high volumetric and gravimetric energy density, ideal for HEV's. This will open the door for more affordable HEV's to come. The day will come when all cars will be hybrids, when electrical components will be more affordable.

Per Roger, this doesn't come close to making economic sense with $3.00 gas.

Roger, Nick: Agreed that at 3$ gas the economics aren't favorable. But how long will it be before the price of gas goes through the roof (if you can get it at all)?

Roger: You might want to revisit your amortized cost of the battery/kwh when you consider two things. First, the 2000 cycle rating is for deep cycles. If you don't deep cycle your battery you will get significantly more kwhs out of it (yes I know that reduces the effective range). Second, the remaining battery still has residual value even after 2000 deep cycles.

Interesting technology, but limited by its use of Nickel.

thats exactly 1000$ too much for me (and future diesel hybrid driver),

in a gasoline hybrid car here in italy you will already save money,
but with a diesel car not;

with my driving pattern,
gasoline here at 1,30 Euro / liter ~4,5$/gal,
65 km that i make daily to my work

i will save with a prius and this pack ~2,6 Eur in gasoline cost. (instead of 3,8 (0,65 * 1,3 * 4,5) i will pay 1,2 Eur for my daily trip to work.

this 2000 times (maybe even more with less capacity)
and i save over 10 years 5200Euro in gasoline cost (6700$)

and you lucky americans with lower price for electrons and higher consuming cars could save even more

I think the problem this forum is that the majority of the contributers
appear to be obsessed with the cost of taking enviromental measures
in our lives.
As a individual who has invested in this types of technology to try
and reduce my impact on the planet , I can tell you that there is a sense
of well being that comes with it , ie hot showers at little or no carbon cost,
due to an efficient solor hot water system , a steal at 4000 euros to heat
360 litres of water from april to october ,without using any boost.
The more of us that can afford to invest in these emerging technologys
the cheaper they will become for everyone .
Ok a prius with a 6kwh battery may cost 6 or 7 k more than the std model,
but just borrow a little more to buy it , it will only hasten the arrival of
this type of car for everybodys budget , and thats got to be a good thing.

Fine idea and sounds like a good product. Where can I receive one?

You could always get a used Prius (warranty already expired or close to it)

Cars.com shows precisely 4 used 2nd Gen Prii in the US with more than 100K miles for sale, starting at $14K. So let's see. $14K for the car, $1,500 to have it shipped to me, then how much is the PHEV conversion? Hymotion won't even put pricing on their website, and the one site I did find that had pricing was outrageous - $24-32K for just the conversion.

Hymotion published fleet pricing (100+ vehicles) at $9,500, so my original estimate of $10-15K for a one-off conversion seems appropriately conservative. Let's take the average ($12,500) as the PHEV conversion cost.

Car - $14K
Taxes and fees - $1K
Shipping - $1.5K
PHEV conversion - $12.5K
Total - $29K

Let's use the Nilar numbers for the battery pack as a baseline for operating costs and lifecycle battery costs.

2,000 cycles
6.4 kWh capacity
20-25 mile range (22.5 mile avg)
$6-7K for the battery pack ($6.5K avg)
12.27 cents/kWh (avg US residential electricity price + taxes and fees)
Energy cycle efficiency of the battery - ~86%

That comes to 4.1 cents per mile for electricity and 14.4 cents per mile for the amortized cost of the battery, for a total of 18.5 cents per mile.

By comparison, a Prius costs 5.9 cents per mile for gasoline and I can get an '08 new Prius for $23K after taxes and fees.

Used car with 100,000+ miles, no warranty, $29K, 12.6 cents more per mile, and even an extra ton of CO2 every 45K miles. Or, a brand new car for $6K less, 12.6 cents less per mile, full warranty, less CO2, and no aftermarket hack that could potentially mess up my car.

Real tough choice there.

@Jack:
I agree there is no question it's not a good time to enter the market for used Prius cars at these price points. And, typically most used Toyota models retain a higher resell value.

I think it's just too early in the game and the demand for HEVs is still high; but, that will change as the other auto companies bring their HEVs to market. Trouble is that could take five to ten years before they hit the used car market place at affordable prices for battery upgrades. Until then, the only low priced Prius' I have found on the market are "rebuildables" from the wrecking yards or flood cars from New Orleans.

Guess I will keep driving the old Volvo for quite a while longer waiting for the BEV and PHEV market to pop.

jack: you are essentially correct (any quibble I have over the amortization of the battery would likely only take the payoff distance down to 150K miles using your numbers). A base Prius is $34,888 out the door (toyota.ca). I'd be willing to pay the extra couple of hundred to keep the extra 9 tons of CO2, and other pollutants, out of the air. Not everyone would.