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Mechanics say they can convert conventional cars into hybrids

posted by: Jeffrey Wolf , Web Producer
written by: Thanh Truong , 9NEWS Reporter created: 10/10/2007 5:39:13 PM
Last updated: 10/10/2007 6:31:07 PM



SALIDA – Several mechanics in Salida, which is about 140 miles southwest of Denver, say they can convert a conventional car into a more fuel-efficient hybrid.


"Everybody seems upset about gas issues, but nobody seems to have an actual solution," said Pete Hansen.

Hansen is one of the salesmen for Salida Conversions. Hansen says the mechanics at Salida Conversions recently transformed a 1999 Chevy Tahoe into a hybrid by installing an electric motor to its drive shaft.

The motor was developed by NetGain Technologies and is dubbed EMIS, or the Engine Motor Interface System. The EMIS is powered by rechargeable batteries.

Hansen says after installing the motor, the Tahoe's city gas mileage went from 12 miles per gallon to about 20 miles per gallon. Salida Conversions says the entire process can be done in less than two days for about $6500 and will save drivers gas money.

"You'll only be going to the fuel pump half as many times," said Hansen.

Steve Hatch and Ron Poyer say they are very skeptical.

At the Lincoln College of Technology, formerly know as the Denver Automotive and Diesel College, Hatch and Poyer are instructing the next generation of mechanics. They say what Salida Conversions is doing can improve gas mileage, but at a very minimal rate.

"There is an advantage any time you assist the gasoline engine with an electric motor. Can there be a slight increase in gas mileage? Absolutely, but I would say it would be slight, maybe a 5 percent increase," said Hatch.

"The idea is sound, I just don't think dollar for dollar to me it would be worth it," said Poyer.

Both instructors say they're skeptical because the voltage which drives the EMIS is not enough to make a significant difference in gas mileage.

According to Salida Conversions, the EMIS requires 48 volts or 72 volts of additional battery power.

More: ttp://www.9news.com/news/article.aspx?storyid=78848

As the article mentions those voltages are pretty low...

If I get a chance to build my EV it will be 144V on a subcompact/compact car frame. That was never even an issue as I need all the torque I can get for grade climbing.

If I'd be putting 144V in a 3,000 subcompact frame (with batteries) how much is 48V going to pull a 7,500 pound Tahoe?

I was recently trying to explain volts, amps and watts to one of my little kids and used the analogy that volts are like the height of the waterfall and amps is how much water actually flows over the edge. Watts are the combined affect and that's where the power comes from. If you have enough amps, low voltage can have the power - but the cabling will have to be much more substantial.

That waterfall analogy is great. It's good to know there are some informed little children running around somewhere!

I was recently trying to explain volts, amps and watts to one of my little kids and used the analogy that volts are like the height of the waterfall and amps is how much water actually flows over the edge. Watts are the combined affect and that's where the power comes from. If you have enough amps, low voltage can have the power - but the cabling will have to be much more substantial.

That's a great analogy to use but one thing to keep in mind is that there are not any controllers that handle more than 650A that I am aware of, and even at levels around 400A the cables are getting big and heavy (#4 welding cable).

On a different note, assuming the batteries are 12V, 48V is 4 units. To achieve, say, 400A with them would require a 100A feed from each battery. That's kind of hard to sustain for long when the biggest batteries available today (deep cycle flooded lead acid) are 85Ah. ;)

This is why almost every EV system runs at 120V or higher. Even the EV motorcycle conversion I mapped out would run at 72V and it weighs less than 500 pounds with the batteries.

Hi All:

___Like I have always said in the past, if you are trying to create an EV from Pb-Acid’s, forget it. The DoD and limited cycles before they are shot make the costs prohibitive. If you cannot access some NiMH’s from whatever, don’t waste your time.

___As for low V and high current, somewhere there needs to be an Inverter/Rectifier and that thing is going to be a monster to handle the huge current loads at 120V or less! I saw a lot of EV home built discussion in the past and for any kind of reliability over any kind of real travel distance and time frame, there were a lot of Hawker’s and Odyssey’s wasted in the process.

___Good Luck

___Wayne

For 400a, the wire size is 4/0 not #4. Lead acid batteries larger than 85ah do exist. One that is used to power large UPSs, that I know, of is 139ah. Since (4) batteries wired in series gives you 48v, the interconnecting battery cables also must be able to carry 400a if you need 400a. In an EV application, if you run a DC motor there is no need for an Inverter to change to AC. But generally AC motors are more efficient and reliable. For high wattage applications you would increase the voltage to keep the current manageable.

The big factor in vehicle propulsion is how many watts does it take to get started from a stop and how many watts does it take to move on down the road. That energy has to come form somewhere, it does not magically appear.

Adding electrical power to get a Tahoe to go from 12mpg to 20mpg is going to take many watts of power.

Lead acid batteries larger than 85ah do exist. One that is used to power large UPSs, that I know, of is 139ah.

Right you are, and the statement I made regarding batteries was pretty generalized. I was going by batteries of a physical size that are close to a "normal" car or marine battery. I imagine a 139Ah UPS battery would be too large and heavy to place 12 of them in a subcompact/compact frame, correct?

100 lbs. Wayne G. is correct that lead acid batteries are not feasible. It is interesting that Thomas Edison came to the same conclusion and was working on a nickel-iron battery a century ago.

The resistance loss equation Power=i^2*R is a very powerful argument for raising V and lowering i.
The quantity of batteries and size of electric motor required to make a significant contribution to a Tahoe-sized vehicle make an equally powerful argument for starting with a reasonably sized vehicle.
A more cost effective conversion would be electric assist brakes or bigger vacuume reservoir for longer assisted braking during FAS.