More proof of a conspiracy

[DiFortissimo]

Originally Posted by theholycow

I imagine that daily use and putting on a lot of miles all at once, you'll get far far more miles out of the batteries than you would with light usage.

I don't follow the logic there. I'd say "you're right" as far as, say, the 12-volt lead-acid battery on a regular car (Prius has one too, of course), but because of the way Ni-MH batteries work, time would not figure into the equation. If you fully charge a Ni-Mh now, then check it again in next year, what you put in it is still there. Of course, this is not so with a lead-acid. On a Ni-Mh, life is figured by charging/usage cycles while a lead-acid has TIME working against it too. Many "civilian owned" 1st generation Priuses (a few of them friends of mine) have a tad over 300-grand now, and still no performance reduction... yet.

Originally Posted by theholycow

I thought that the electric motor was an important part of the Prius's performance and assumed that it's painfully slow without it. Am I wrong? (I really haven't given much attention to the Prius.)

Well, not exactly "wrong," but the gasoline engine has about 76 horsepower (which is kinda low), and the normal torque for its displacement. The rub would be that the Prius's gas engine is what's called "Atkinson cycle" (it's not really, but don't get me started... it's still a cool idea by a Scottsman) and, as such, trades low-end torque for lower (MUCH lower) pumping losses at low-rpms. As it revs, the variable cam timing turns it into a regular "economy tuned" 1.5L four banger.

Minus the battery, power-to-weight would be much better than an early VW Beetle, and slightly worse than the last Beetles (in the USA, anyway) of 1974-1978. The lack of low-end power would be shielded greatly by the CVT transmission, which would let the engine rev 'til it was doing what your foot told the accel pedal you wanted. Perhaps not great low-end, but no certainly no "bogging."

Originally Posted by theholycow

This is one of the major reasons you're unlikely to see me in a Prius. I don't want attention.

Well, it's been quite a while since a Prius would garner you any attention. Back in 2006 you'd have gotten attention, but not any more.

Following two-years of speaking to at least three people every time I'd stop for gas, the Prius's novelty is now long gone. Haven't had a single inquiry in over a year now. My little town went from having 3 Priuses total in 2006, to somewhere in the 400-500 range today. In southern California you stick out more if you DON'T drive a Prius. My buddy (who works with Steven Spielberg, if you like to have names dropped pretentiously) says, "Here in Pasadena, every 3rd car is a Prius."

I can understand your not wanting one, but 'flying under the radar" is not the reason. At least it no longer is.

The Civic Si was "right" for me, but I didn't like it. The Prius (which you can Google and find me raving against... vehemently!) turned out to be "right" because it's a $35,000 car I can buy for 20-grand. ($23,450 and I got the $3500 tax rebate).

Now, you know the cars I drive (Prius, '59 Austin-Healey hot rod, and SmartCar) so, just out of curiosity, what car is it that you employ to "fly under the radar?"

Bestooyoo, Moderator-type-person,

ADiF

[theholycow]

Where I drive the Prius is still pretty uncommon. At least nobody would bother me about it at work, one person has one; well, maybe that person would bother me about it.

My 2008 VW Rabbit is not as invisible as I thought when I first chose it. Luckily, I never intended to keep it permanently. It doesn't start many conversations; I think the only stranger ever to talk to me about it was someone who was interested in buying one and wanted to know about it. I was happy to talk about my likes and dislikes in that context. It has gotten me one ticket that I think I wouldn't have gotten in something more boring.

My 2002 GMC Sierra used to be 100% invisible, but now it's turning into an old vehicle. It doesn't attract much general attention but as it gets older I look more like someone worth pulling over.

My next car, to replace the VW when I'm done with it, may be a 1996-1998 Volvo 850. They seem to meet most of my requirements. They do stick out like a sore thumb with their modern paint and details on 1980s square-bodied shape, but I doubt they really gather any attention. I'm not sure about that, though.

[VetteOwner]

Probably the same thing that I found wrong with 'em: The people who buy them!!!. Most Prius owners are religious zealots, and think they've finally found God in their car, and you're 'unwashed" if you can't "follow the light" and buy one... like they did.

not saying you are but yea it seems some owners like to gloat the fact they have one. lol reminds me of that south park episode of too much smugness over the city

Next thing y'know, they'll be going door-to-door on bicycles trying to talk everyone into the "buy a Prius, save the planet" concept. Me? My dad died and left me ALMOST enough money to buy a new car. I paid cash for new 2006 Honda Civic Si. Kept it 8-months, put 1100 miles on it, and sold it. Very boring, juvenile car, which I didn't "get" 'til I'd lived with it a while. My first new car; lesson learned. Let your eyes make suggestions, but don't chose a car (wife?) with them. I (of course) think my wife's pretty but, even if she weren't, there would be tons of good things to recommend her. It's the same with my Prius... except for that "I think she's pretty" part. (chuckle) A Prius's beauty lies in the fact that it greets the air with a .26 drag coefficient, lower than anything in production. (the old out-of-production Honda Insight was .25, and so is the new Prius)

lol yea while my chevette gets decent milleage for its age and what its got, its not emmisions friendly. mostly cuz there isnt any left on the car lol

Bought the Prius 'cause it's HUGE inside, and I can barrel up-and-down the Interstate at 80mph getting 50mpg. My 60,000 mile FE average is 67-and-some-change. If I were to take out the Interstate trips, it's close to 74mpg. Modifications consist solely of 48psi front tires, and 42psi rear. And so it was that we came to welcome the Prius into our stable.

see i find the inside the same size as any ol car of its well size lol. id compare it something slightly bigger than a caviler (barely)

I have a '59 Austin-Healey BugEye Sprite with a 195 horsepower Mazda RX-7 Rotary engine... does that count? (550cfm Holley 4bbl on Racing Beat intake manifold and hand-crafted (beautifully, I might add) headers & exhaust. Also fitted with wide three-piece wheels and lightly-treaded DOT-legal racing rubber.

Stock '75 MG midget rear end, so just sidestep the clutch and you'll disappear in cloud of.... spider gears & pinion shaft shrapnel. Don't ask me how I know. It was freak accident caused by my hitting a patch of sand under power in 1st gear. One rear wheel spun, then caught traction again, followed by two quick "axle-tramp" events. Whereupon the spiders did their ashes to ashes, dust to dust routine & disintegrated. Since it weighs almost nothing, I pushed it the two miles back to my garage.

sweet, ive heard stores of some chevette rearends "grenading" like that but i think it was because of leaks that let it run dry. (kinda of a dumb design but it works, least its RWD (right wheel drive)

You are right about parts prices, but admit it: That's a red herring. If Toyota prices were cheaper than Chevette's, would you buy a Prius? Didn't think so.

yea ur right i wouldnt lol...

Besides, there's two ways to look at it: One cheap car that needs lots of cheap parts, or a moderately-priced (and NEW) car that with proper care needs almost NO parts... . There are many documented 350+ thousand mile Priuses with all original brake parts (in taxi service, I'm assuming occasional brake fluid change, but don't know this) so it doesn't matter to me what a Prius caliper costs. BTW: As of this writing, those taxis still have their original traction batteries... with no apparent degradation.

yea true but once i replace everything that could possibly be wrong its good for a very long time. most of the parts i replaced because of age and or it sat a while so the brakes got a tad sticky. that will happen to any car i dont care what.

Also, regarding the "Prius's traction battery; the "JUST YOU WAIT" idea is a valid point to bring up, but is also of no consequence. The Prius runs just fine without the expensive battery, and I don't know how any rumor to the contrary ever got started.

does it? (i really dont know) i mean does it need some battery left to run and control systems? cuz eventually its going to be flat dead and hold no charge. not like ye old carbed cars that the battery was pretty much ONLY for starting the car, most can run without it.

Yeah, it'd be nice for people who don't bother with maintenance, but no-can-do with the Prius's 13-to-1 compression ratio. Time-is-money, and compression-ratio-is-fuel-mileage. Besides, all cars seem to be returning to the chain. Belts are almost gone now.

well sometimes its not even regular maintenance, sometimes the belt can have a flaw or something can get in between it (oil deteriorates rubber, front crank shaft seal leak anyone?) so id rather have the insurance that IF something happens its going to be fine. it only takes once to destroy an engine if a belt/chain breaks)

I have cars like yours, and I have the Prius too. I bought it 'cause it was NEW, and BIG, and THRIFTY. People at the gas station ask me, "Yeah, but how many miles will it take you to reach payback on that fancy 2,000-dollar hybrid system?"

i dunno, the new cars of the last ohhh 10 years or so seem boring to me. rather own something old cheap and economical lol. reason being old cars i think are built better, can buy them for next to nothing if you look hard enough, they all used the same engines so parts are plentiful, thier simple, seem to ride smoother to me anyways, etc i can go on and on.

lol i just get asked what mpg i get outa my chevette then see thier face explode when i tell them

Now VetteOwner... I do believe you're JEALOUS! (spoken in girly-like voice).

haha nah far from it.

That would be a nice cheap way to drive. I've only ever seen two-or-three of 'em... well, more like "heard two-or-three." Were they "low-production" rare or is it just attrition that's whittled down their availability?

well the problem was that it was the most expensive package you could get for the chevette, which bumped it up to a price that you could get something larger with more power for the same price. you can find em but thier hard to find.

it was the best selling small car in the US for 1979-80

about 2.8 million were sold 1976-87 hence why everyone and thier grandma either had one or knew someone who had one

started off around $3K in 76 and wandered its way up to only $5K in 87

lol i feel the need to have another, a 2 door specifically. would love a diesel engine one with a 5 speed tranny but would be happy with a gas with 4 speed (MUST be manual tranny, severely underpowered for an auto tranny)

lol on a side note: i SHOULD have gotten pulled over many times in my chevette from speeding but havent. i dont know if the cop couldnt belive what his radar gun was telling him or if he just stared at seeing one lol (one particular incient is going 85 in a 55 LOL)

[trollbait]

The Prius needs the traction battery to run, or at least start. The 12 volt battery is wimpy. It is smaller than a typical car battery, but then it just has to boot up the computer and close the circuit to the traction battery. The traction battery is needed to turn over the engine.

Now, if the traction battery is degraded to the point where it just holds enough juice to turn over the engine, the car should still be able to move. It should also have more than the power of engine alone. There will be some series hybrid action going on giving you low end torque.

On the other hand, a battery in such poor shape is likely going to throw codes with the attending array of lights and warnings.

[dkjones96]

On the bright side, I'm able to help you guys with the traction battery debate. However, you are all wrong, to an extent. The battery may have enough energy to start the engine but that doesn't mean it has the energy required for the car to accelerate.



Because of the way the torque split device works in the Prius the electric motors(MG1 at the very least) have to create enough torque to match the engine's output. That would be assuming you were accelerating with no assist. If MG1 gets no power the engine spins the planetary carrier and torque goes to wherever the least resistance is, that just happens to be a freewheeling or grossly underpowered electric motor attached to the sun gear, NOT the ground on the ring gear. If the Prius was equipped with a load cell it could load up the generator and the car could at least limp around, wastefully at least.

MG1 is what they call the generator in that image. It is both a generator and a motor. If you have a dying battery(to the extent we are talking about here) the generator can't charge it. If the generator can't charge it, the generator can't apply a load. If the generator can't charge it there is nothing for MG2 to run off of. If the generator can't charge it there is nothing for MG1 to work with to maintain at least a stall so the car can move.

The Insight, however, has an actual transmission. That car can run without a traction battery.

[trollbait]

My understanding of the power split device is that a set percentage (around 27%) of the torque generated by the engine goes to spinning the MG1, the rest goes to the wheels. Now the MG1 generates electricity with that torque. Are you saying the electricity is always routed to the battery and then to the MG2, and it can't directly route it to MG2?

I was wrong saying 'enough juice to turn over' in my previous post. Perhaps the car could limp along with a near dead battery, assuming it's technically possible and the software will allow it.

However, I think when people speak of replacing the traction battery, it isn't at the point of being dead or near death, it's at the point where it doesn't provide the benefit of performance and economy. The Prius keeps its battery at 40% to 80% state of charge to maximize battery life. Early Insights weren't so conservative, and some MT cars killed the battery. Now, when the Prius battery hits a point where it can't hold above 40%, the computer will likely avoid tapping into it to fully power the MG2. Accelerating will take longer and economy will drop.

The point is that the driver will notice something is wrong, and to get it right, he'll need a new battery. But the battery isn't at the 'can't light a flashlight' point. Utilities are looking into using hybrid packs no longer good for cars as an UPS and peak load buffer for buildings. So the average person would consider the battery dead because it no longer does its main function in the car, but the Prius should still be able to be driven. Doing so will likely hasten the battery's true death.

A truly dead traction battery in Prius means it isn't going anywhere, even if you somehow manage to start the ICE. Does the Insight have a seperate starter, or can the 12 volt battery spin the MG for starting? Yeah, it can run without the battery, but can it start?

[dkjones96]

I'm not 100% sure on the operation of the hybrid system in the Prius as far as routing power from MG1 to MG2 goes. I imagine that once MG1's output has been rectified into DC it is just as capable of being used by MG2 as battery power but you never know. The battery is tended by its own management unit that is between the battery and both MG control units.

[DiFortissimo]

Originally Posted by dkjones96

I imagine that once MG1's output has been rectified into DC <snip>

I'm no electronics guru but, depending on what you mean by "rectified into DC," I don't think it does this.

For instance, on the 1st-generation Insight, the variable DC voltage to the IMA (the electric motor that assists the gasoline engine) is not DC voltage. It's "chopped-up AC" voltage that, to the IMA's DC-powered unit, appears to be "DC..." but is not.

It's the same thing as your computer's switching power supply. The computer uses DC voltage to run the motherboard, hard-drives, etc. The power supply provides this DC voltage, but it does not take AC and convert it to DC. It is not DC voltage. What it does is to (for lack of a better term) chop up the 110-volt AC and dole it out so that, to the awaiting peripherals, it looks feels, smells and walks like DC power... but it isn't. Not really. It's conditioned AC voltage running DC periphals.

The switching power supply was the just-in-time development that made home computers viable. Not made them possible, but rather, it kept them from weighing 150 pounds (full of copper) and costing 10x as much. Your computer's P/S takes 110v AC wall power and "chops" it into something that appears to be 5-volt and 12-volt DC power... but it's not.

My guess is (and someone may actually know) that there is no true DC voltage anywhere in a Prius except whatever comes out of the 12-volt DC battery. I'd bet a fresh new 5-dollar bill that this motorcycle-sized 12-volt DC battery is charged, not by "AC inverted to DC," but by digitized "chopped-up AC" that appears to the battery to be 14.5-volt DC power... but isn't.

There's got to be an electronics wizard around here somewhere.

ADiF

[Jetta90GL]

DC voltage can not appear to be DC but be AC. DC is Direct Current, meaning electrons flow in ONE direction. AC current is Alternating Current, meaning it flows in opposite directions creating a sine wave.

The difference between switching power supplies and Linear power supplies, is that a Linear supply creates say a flat line of 12 Volts on an oscilloscope, while a switching supply creates a pulse that goes higher and lower than 12 Volts, but to the electronics it feels like 12 Volts. In no time does it ever reverse current flow. Switching power supplies were created to be more power efficient.

[DiFortissimo]

Originally Posted by Jetta90GL

Switching power supplies were created to be more power efficient.

I thought all that was pretty-much what I said. Perhaps if I knew more than I do, then that is exactly what I would've said. This boils down to semantics which, as is obvious, I don't know all the little idiosyncrasies of. By "not really DC" I meant that it was not AC that had been run through an inverter and CHANGED to DC... which would be possible, but very wasteful.

It seems we agree vehemently.

ADiF