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xcel
09-06-2006, 04:58 PM
Car owners modify popular hybrid. (http://www.insidebayarea.com/search/ci_4288208)

Jessica Hilberman – Inside BayArea.com – Sept. 5, 2006

http://www.cleanmpg.com/photos/data/501/Prius_II_CalCar_-_PHEV_Mod.jpg
Photo: Ron Lewis - John Davi shows off a plug-in Prius, a car that's outfitted with a special bank of batteries and gets 100 miles per gallon.

THE PRIUS has revolutionized the way Americans think about gas mileage. In just a few years, we went from being the country of the Hummer to a country where smaller, more efficient cars are suddenly all the rage.

In the Bay Area, people wait months to get a hybrid, dreaming all the while of cutting their fill-ups and zipping through the carpool lane. And some dream of all the changes they'll make after it arrives.

They are Prius hackers. John Davi is one of them.

Communications director for the CalCars Initiative, an advocacy group working to promote adoption of non-polluting automotive technologies, Davi's professional life revolves around bettering Prius gas mileage to more than 100 miles per gallon; it's done by adding a bank of batteries to existing cars.

Based in Palo Alto, CalCars' goal is to get just one U.S. automaker to sign onto making so-called "Plug-In Priuses" - Priuses that get 100 miles to the gallon.

"All we do is put more batteries into existing Priuses and add a plug," says Davi, of Palo Alto.

The idea is simple: Add batteries in the Prius' trunk so that it's able to run mostly on electric power. In effect, CalCars wants to see electric cars with a gas-power backup, rather than gas-powered, sometimes-electric vehicles.

The idea is catching on. Though there are only about 12 plug-in hybrids in the world now, at least two companies are planning on marketing kits that would allow Prius owners to add batteries and convert their own cars.

The first is due out this fall, spurred on by interest in a plug-in conversion performed at the Maker Faire in San Mateo in April. Over the course of the weekend, CalCars worked with volunteers to transform an average Prius to a super, 100 mile-per-gallon commuter-dream car.

They did it to send a message to automakers.

"We wanted to show Toyota and Ford that the batteries in their current hybrid can be used to make it work," Davi says. "If a bunch of backyard engineers can do this over a weekend, why can't the car makers?"

In answer to his own question, Davi says, "The only reason they don't want to plug in right now is that they don't know they can."

The goal of the Maker Faire conversion, CalCars' third, was to show the automakers the possibility of plug-in hybrids.

Of course there is a catch. Davi admits that dramatically modifying a Prius could void the warranty, and a Toyota spokeswoman concurs. Any modification that affects battery life voids the warranty, according to Mira Sleilati.

But Sleilati also says Toyota is "exploring opportunities for plug-ins down the road, as advances in battery technologies are researched and developed."

That's good news for CalCars, which may be nearing its goal in getting an automaker to sign on to plug-ins.

But while plugging in costs a few thousand dollars and is still in its infancy, other Prius modifications are growing in popularity. They are as elaborate as installing a MacMini computer with a touchscreen in the dashboard (a serious hack) and as basic as learning to shut off the interior, some argue annoying, beeping the car makes when it's backing up.

One of the most common hacks people are making is adding something called the EV button to their cars. It's pretty easy - the Prius is already set up to run on all-electric power for a few miles, but because of complicated emissions standards, the EV button is not a factory option in the U.S.

However, savvy drivers can have a European or Japanese friend send one from abroad and install it themselves, or they can turn to the Internet.

That's what Stephen McGrogan did. An electrical engineer from Pleasanton, McGrogan bought his white 2004 Prius to save money on his long commute and he quickly fell for the car.

"It's beautifully designed," he says. "It's very well-appointed in terms of cup holders and the sound system. Very quiet of course, rides well. It's a very usable car."

McGrogan uses his Prius to haul wood and loves the flat-folding seats.

Yes, and he can go 520 miles on less than 10 gallons of gas.

McGrogan's first experience with after-market Prius gear was with a bike rack. It's hard to put traditional bike racks on the hatchback, so he ordered a special Prius rack from Coastal Electronic Technologies. (Davi calls it the "everything you wanted to hack about your Prius but were afraid to ask" store.)

Enamored with this purchase, McGrogan decided to try his hand at real hack.

He teamed up with his son David to install an EV button. It was easy.

He says, "It was fun. I held papers and he did it. It's just pulling out a couple of connectors."

EV mode cuts down on noise in the community, says McGrogan. When he drives down the street to church, he doesn't have to wait for the Prius to go through its uninterruptible warm-up cycle; he circumvents it and keeps the car in all-electric mode where there's no engine noise and no gas used.

While McGrogan sees the EV button as a boon for convenience, Davi points out that it's good for the environment, too. "Start-up is the most polluting part of the engine cycle," he says. "Electric mode is useful for short distances, and you can keep the engine off when it would otherwise make more pollution."

So is the EV button a good substitute for the plug-in Prius? No, says Davi. "The button is nowhere close" to as effective as the plug-in cars he envisions taking over the road. "The EV button is great. It's a fun gadget," he says, but it's "not a victory."

Meanwhile, McGrogan has more plans for his Prius. He says, "Newer Priuses have a sound jack. I would like an option that does that, but the kit hasn't come yet."

So he waits, just as Davi waits for the big automakers to recognize that they're already building the car of the future - it just needs a couple of modifications.

antrey
09-06-2006, 10:21 PM
What kind of mileage improvements can be expected from the EV button?
Has anybody done full aero mods on a prius similar to basjoos' civic?

xcel
09-06-2006, 11:01 PM
Hi Antrey:

___None and in fact, can reduce a Prius’ FE if used incorrectly. Add a huge Li-Ion pack and it becomes huge as anything below 35 will keep the ICE off and you can run on the pack all you want … Within torque limits and SoC. If you want too much, that ICE is coming on no matter if the button is pushed or not.

___Aero mods on a Prius II? It already has a Cd of .26. Every bit helps at higher speeds but if you are seeking super FE from a Prius, anything below 40 and she sings with the best on the planet … Other then an Insight of course ;) At 65 +, you are beginning to not really care about your FE anyway :(

___Good Luck

___Wayne

psyshack
09-07-2006, 06:34 AM
I wonder if they are upgrading the electric motor when this more EV mod is done?

There has been a move in the electric motor world over the last 5 years to make them smaller and more compact. This cost cutting move has been driven by the rising cost of copper, steel and production.

The answer has been higher class insulation to get these cheaper to make smaller electric motors. The result is high skin temps on all electric motors. Higher skin temps lets one know you have much higher internal temps and bearing temps.

It would be awful to build a more EV mode modded car and over look the electric motor and risk burning it up.

xcel
09-07-2006, 07:39 AM
Hi Psy:

___No, they do not upgrade the motor when the PHEV mods are done. There is a concern about lubrication after 7 + miles of EV and one the prospective PHEV companies do not have an answer for that I know of?

___One of the items the electric utility industry has used for 40 + years is square wound power cabling inside the Generators. The HCH-II’s MGSet uses this exact trick to increase performance while reducing weight. Even more current capability with less heat generation in a smaller overall package. I really doubt the shrinking of Hybrid components will lead to pre-mature failure(s) due to heat build up. Same with the latest super packs … They are being cooled passively without the need for A/C as the current FEH’s must be. Just one more example of where we are headed.

___Good Luck

___Wayne

TonyPSchaefer
09-07-2006, 10:41 PM
What kind of mileage improvements can be expected from the EV button?
Has anybody done full aero mods on a prius similar to basjoos' civic?I have an EV Switch in my 2004 Prius. Let me tell you about it.

First of all, you really need to understand that the Prius gets its worse mileage when the engine and catalytic converter are cold. In this case, the engine will run to warm the parts rather than propel the car. In fact, sometimes within that first five minutes, the engine runs when I'm sitting still whether I like it or not. The engine will simply not shut off until the whole system is warm.

Secondly, if the hybrid battery gets too low, the engine will run to recharge it. In fact, if the battery display shows less than half-charge, it is much more difficult to get the engine to shut off while the car is moving.

The Prius is very good at stealthing and operating purely in EV mode. But only if you follow the rules; if you violate those two rules above, all bets are off.

When I installed my button, I knew it came with advantages and possible issues. So for the first tank, I used it sparingly and very judiciously. Contrary to my normal experience, even though there was a sharp turn in ambient temperature, my mileage went up. For sure this was due to my EV button.

So for my second tank, I was a little more laxed in my usage. I used it more, I EVed through parking lots, from stoplight to stoplight, and around the suburb just for the heck of it. Even though it was going into the summer and the average temperature went up, my mileage went down. Again, I suspect it was due to the EV button.

Upon review, I realized that by using the EV button, I was clearly violating the rules of "cold engine" and "low battery." And being the multitasker that I am, I was able to do them both at the same time: by running on EV, I was draining the battery too low and forcing the engine to sit idle and cool down.

So I'm back to being extremely careful about using it. I'm tempted from time to time to punch the button and cruise for a while. But I know that I run the risk of over-using it and forcing the engine to run more.

I hope that helped answer your question. If you need more information, please feel free to ask.



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