Hymotion launching Prius plug-in conversion kits
Filed under: EV/Plug-in, Hybrid, Toyota

All you Prius owners out there who have been waiting patiently to to start running on grid power can almost stop holding your breath. Hymotion, the company that has been developing a plug-in kit for the Prius, has now started taking deposits for the L5 conversion kit. The kit costs $9,995 plus $400 for shipping and, of course, any applicable taxes. That price includes installation at an approved shop and a three year warranty. The first deliveries and installations should start this July.
The kit consists of a 5kWh battery pack filled with A123 lithium ion cells that fits into any second-generation (2004-2008) Prius. The pack can be fully charged in 4.5 hours at 110V and Hymotion claims a converted Prius will get up to 100mpg for 30-40 miles. Your mileage will of course vary. The pack has been crash tested and meets all current federal safety standards. Hymotion was bought up by A123 last year after doing a number of conversions for fleets and government testing.
[Source: Hymotion]











Reader Comments (Page 1 of 2)
4-27-2008 @ 6:28PM
mike said...
Does it come with a plug?
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4-27-2008 @ 7:06PM
BlackbirdHighway said...
So, a brand new Prius, with the Hymotion plug-in battery pack, costs less than the latest estimate for the Chevy Volt, and it's available this summer, instead of having to wait until at least 2010?
GM should just give up now, they have already been beaten! Completely!
Wonder if Hymotion is working on kits for other vehicles, the hybrid Camry, the hybrid Highlander, etc.
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4-27-2008 @ 7:46PM
ug said...
It costs less because it doesn't do as much as the Volt will. It's still based on the Prius therefore it will not run in EV mode on the freeway. Your mileage gains will therefore be restricted to stop and go city driving environments. Depending on your commute it may not save you that much money.
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4-27-2008 @ 8:00PM
Chris said...
Your X-Prize winner is...
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4-27-2008 @ 9:00PM
Chris M said...
Hymotion had been talking about providing plug-in upgrades for the older (pre-2004) model Prius, the notion was that the basic warranty would have expired, meaning less worry about violating warranty terms.
Of course, there are a lot more of the newer models on the road, Hymotion may be aiming at a larger potential market.
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4-27-2008 @ 9:51PM
john1701a said...
>> Your mileage gains will therefore be restricted >> to stop and go city driving environments.
No, that's not how FULL hybrids like Prius work. The electric motor contributes during highway cruising too.
In other words, the upgrade provides an efficiency BOOST.
Based on Google's mini-fleet of Hymotion augmented Prius, their average is 66.2 MPG
http://www.google.org/recharge
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4-27-2008 @ 9:56PM
GoodCheer said...
This seems like a really great development.
ug: While it is true that the Hybrid Synergy Drive requires the ICE be turning over to exceed about 25 mph, I suspect that the 5 kWh can still provide 15-20 miles worth of fuel savings at any speed.
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4-27-2008 @ 10:09PM
john1701a said...
>> While it is true that the Hybrid Synergy Drive requires
>> the ICE be turning over to exceed about 25 mph
No, it's 42 MPH.
And the prototypes currently being tested by Toyota raise it to 62 MPH.
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4-27-2008 @ 10:32PM
JT said...
Saw the Progress Energys Hymotion Pruis that AVRC (www.avrc.com)here in Raleigh NC did for them... The install and system looks very nice. Still saving my money to get mine done...
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4-28-2008 @ 7:59AM
Twitchy said...
Two questions:
1)So this doesn't turn the Prius into a full into a full EV? I ask as I only need predominantly short transportation.
2)Will it charge on 220V with or without modification? And if it will charge, how long for a full recharge?
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4-28-2008 @ 8:05AM
rar said...
10 grand can buy you 2,500 gallons of gas at 4.00 a gallon. The stock Prius gets about 45mpg. Thats about 112,000 miles of driving. You would realy have to drive a lot or keep your car a long time to make that worth it. Plus you void the new car warrenty.
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4-28-2008 @ 8:26AM
Sean said...
@Twitchy:
1) As far as I understand, it doesn't mess with the car's core electronics at all, so for short trips under 34 MPH and gentle acceleration, it's nearly a full EV except for the engine warm-up (which you can avoid by adding an EV button. Very easy to do. http://www.calcars.org/prius-evbutton-install.pdf )
2) You'll have to ask Hymotion about 220V capability. My guess is no since it would make for a more expensive charger to have dual-voltage capability and they want to target ease-of-use. (Everyone has a 110V outlet handy. Not so much for a 220V except us EV nuts. ;) ) In any case, a 220V charger would technically charge in a little more than half the time in the bulk stage given the same current. (If it's a fancy multi-stage charger then the pulse charging phase will likely take the same amount of time since that's dependent on the batteries rather than the power input.)
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4-28-2008 @ 11:35AM
Joseph said...
If their product is the real deal, which I expect it will be since A123 is building up quite a reputation, there will be quite a bit of demand.
I hope they will have the capacity to provide their product and install their product in rather large numbers.
Otherwise, the price will skyrocket since demand will be high and supply low.
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4-28-2008 @ 2:02PM
Ben Kaun said...
I'd be interested to know the weight and volume of this plug-in conversion. Does it require the OEM pack to be removed, or is it added in parallel? It's priced to be accessible to the affluent, green early adopter consumer market in addition to taxi fleets, which I find exciting. However, it seems that there is some question as to the value of PHEV conversions, because they pull the ICE operation away from its maximum efficiency, causing some more pollution (I'm not an expert on ICE's, so I'm looking for elaboration from an expert here).
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4-28-2008 @ 3:26PM
Stins said...
As much as I love me some Tesla, Fisker, ZENN, Volt and every other EV option, I genuinely believe that in the near-ish future, it's going to be all about plug-in hybrids. This is a great step in getting consumers more experience with the viability of the technology. I'll be pulling for it to work.
It has been added to the Green Product Site Huddler if anyone has a chance to try it out:
http://greenhome.huddler.com/products/hymotion-l5-battery-pack
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4-28-2008 @ 7:09PM
Faith+1 said...
What's the cost in fuel (as in spent) to generate the electricity to charge a battery to keep running at optimum? The grid isn't powered by magic electricity fairies. I'm just wondering if the gas I'm saving personally makes up for what the overall burden on the grid will be?
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4-28-2008 @ 8:11PM
Kevin Nugent said...
OKay so when will i see my gas savings come back to me again ?? Due to the 9000 dollar plus premium
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4-28-2008 @ 9:17PM
Jon said...
My company has been thinking about this upgrade as a promo. To answer a few questions raised above, based on my understanding of the proposal we're considering:
* The conversion fits into the spare tire well of the Prius.
* It doesn't touch the OEM equipment. Apparently, Toyota build the system to accept additional battery capacity. They just plug in the extra batteries, and the additional capacity appears on the Prius screen.
* It doesn't void Toyota's warranty.
* They have a kit for the Escape now also; others on the drawing board, I gather, but only Prius and Escape right now.
* The cost comes out to about 75 cents per mpg for the power off the grid. If you can get a variable pricing scheme from your local utility (i.e., paying less for power at night when there is less demand), you might be able to make that lower.
* It has a plug.
* Recent studies show that most driving consists of fairly short trips at moderate speeds. The plug-in tech is perfect for this sort of situation. I saw a promo that suggested an "average" driver might need to fill up once every other month. Now, if your car is a dedicated to long commutes, etc., etc., etc., your mileage may (literally) vary.
* Three year warranty on the conversion kit.
I agree with the comment that suggested that this is still a pretty steep price to pay for what you get. But the price of the kits will almost certainly come down and the price of gas is almost certainly heading up, so it's one to keep a close eye on.
Now, when they add the ability to reverse the power (from car to house), you'll have an emergency back-up generator too. Think about that.
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4-30-2008 @ 4:26PM
Howard said...
While this sounds great it is really a very stupid investment based on the economics. As was pointed out even at $4 a gallon it would take over 100,000 miles just to break even - not even considering the time value of money. Further, who knows what gas prices will do, most likely after going up a little more they will drop quite a bit. The economics just are not there. If it was a $2,000 option then it might make sense.
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5-09-2008 @ 1:16AM
JP said...
If you are thinking about the economics, don't forget that that the oil supply is finite.
We can talk about the economics all we want, but I guarantee that if/when we run out of oil in the future, we will all wish we saved more fuel now.
If we save more now, more will be available later. We are avoiding and/or minimizing future increases.
The above economic "analyses" are far too short-term in my opinion.
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