More proof of a conspiracy

[Jetta90GL]

The part that is wasteful, is filtering and regulating the voltage. AC can be converted to DC with a simple Bridge Rectifier with little waste.

[CA ExhaustCoatings]

http://www.lawfulpath.com/ref/greening.shtml

"After exploring a whole range of "substitute" possibilities, such as a war on poverty, space research, even "the credibility of an out-of- our-world invasion threat," the Special Study Group reports and Doe recites." It may be, for instance, that gross pollution of the environment can eventually replace the possibility of mass destruction by nuclear weapons as the principal apparent threat to the survival of the species. Poisoning of the air, and of the principal sources of food and water supply, is already well advanced, and at first glance would seem promising in this respect; it constitutes a threat that can be dealt with only through social organization and political power. But from present indications it will be a generation to a generation- and-a-half before environmental pollution, however severe, will be sufficiently menacing, on a global scale, to offer a possible basis for a solution."

I hope you didn't skim over the preceding paragraph. It explains, with almost unbelievable boldness, that environmental concerns were an almost perfect replacement for war, but it would take a generation or a generation-and-a-half (that is, 20 to 30 years) to bring this about. Remember, we are talking about a report circa 1967."

[slurp812]

Originally Posted by Allargando DiFortissimo

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.

ADiF

Ni-MH batteries self dis-charge fairly fast.
http://en.wikipedia.org/wiki/Nickel_metal-hydride

[DiFortissimo]

Originally Posted by trollbait

the computer will likely avoid tapping into it

I see. So you don't know either. How is it then, if we both get to speculate, that your speculation (based on... well, not much) gets to be correct, while my speculation (based on the Toyota engineers having enough sense to give the generator the ability to directly power the CVT's controlling device) has to be wrong? Must be pecking order.

As mentioned, it would take some kinda REAL doing to wear a Prius's battery down to where it couldn't start the engine. The traction battery is, of course, a bunch of individually-replaceable cells, not a monolithic all-or-nothing design.

The battery will eventually wear down, but for it to just go "dead" is extraordinarily unlikely. Wherever that "wear down" point is, we know it lies far beyond the 350,000 mile mark as many 1st gens (both private and commercial) passed that mark years ago, and I have corresponded to the owners by private e-mail to get their impressions on what they've noticed on battery life.

When the millions-and-millions (thank you, Carl Sagan) of Prius's get ready for new batteries, they'll be available at Wal-Mart and cost less than a set of tires.

ADiF

[DiFortissimo]

Originally Posted by slurp812

Ni-MH batteries self dis-charge fairly fast.
http://en.wikipedia.org/wiki/Nickel_metal-hydride

Yeah, that's what I've read. All I know is that my Prius has, with a normal charge, sat around for a couple of months and, when I got back to it, I turned it on to check the battery state... and it appeared to be about the same as when I left it.

Not to say it didn't go down some, but the number of "bars" on the battery's LOC (level of charge) were in the same place. Also, I know we're not talking about a NASA-spec'ed charge meter here, but it's useful enough to tell me that I don't lose too much.

There's a new(er) kind of NiMH that's been around for 4-or-5 years and it's supposed to not discharge from sitting... much. I don't know if the Prius's battery is of this type, and wouldn't know who to ask... besides Panasonic, and they don't return my phone calls. (insert giggle track here)

But the original question was one of longevity. For instance, I'd SPECULATE that you could buy a new lead-acid and a new NiMH battery, let them sit 25-years, then try to charge them. The NiMH would likely charge right up, but I don't think the lead-acid would. I've never gotten around to proving this since every time I begin letting the Prius's battery sit for a 25-year period, I get all impatient after a couple of days and have to go drive the car on a 900-mile trip so I can use up 15-gallons of gas. Thereby messing up the test results. I'll be sure to report if I ever make the full quarter-century.

Also, as I understand it, NiMH batteries will eventually go bad just from sitting, but my electronics buddy SPECULATED that 100-or-so years may be involved. This is not losing a charge, but rather, "going bad," as in no longer chargeable.

ADiF

[trollbait]

While there are safety issues, the main reason the Prius physically disconnects the traction battery on shut off is to limit self-discharge.

I assumed Toyota engineers would design the Prius so that it can run without the battery. But I've never spoken to one, and all my Prius info comes from, some in-depth, fan sites and news articles. Unless I'm 100% sure on something, I avoid speaking in absolutes. Specially if I don't feel like taking the time to link sources. It's best to avoid assumptions, in all cases.

So the Prius can run without the battery. A non-hybrid car run without a top gear or two in its transmission. In both cases, the car's performance is seriously compromised. Only the cheap or really lazy won't bother to fix the car at that point.

[VetteOwner]

Originally Posted by trollbait

While there are safety issues, the main reason the Prius physically disconnects the traction battery on shut off is to limit self-discharge.

I assumed Toyota engineers would design the Prius so that it can run without the battery. But I've never spoken to one, and all my Prius info comes from, some in-depth, fan sites and news articles. Unless I'm 100% sure on something, I avoid speaking in absolutes. Specially if I don't feel like taking the time to link sources. It's best to avoid assumptions, in all cases.
So the Prius can run without the battery. A non-hybrid car run without a top gear or two in its transmission. In both cases, the car's performance is seriously compromised. Only the cheap or really lazy won't bother to fix the car at that point.

hehe very good, engineers just design the thing not focusing much practicallity or ways to repair the thing

[trollbait]

At the other end of the spectrum, it is possible to drive the Prius without gas, and people have done so. There are plenty on the fuel 'guess' gauge, so it isn't a surprising occurance. I figure most people who have done so had no problems after limping into a gas station and filling up on the grounds non problems don't get attention. But some people needed a tow to the dealer afterwards. Never happened to me, so I don't know what type of warnings the car gives the driver. Perhaps it is completely the users fault, but the engineers are human too.

I do believe that the Toyota engineers did take into account efficiency, practicallity, repairability, etc. I also believe the Prius can technically be driven without the battery. But I do know the engineers were really conservative when it came to protecting the hybrid system. The traction control has been the bane to those that have to drive in snow and ice. But its purpose is protect the system from over-revving and can't be turned off. So while you should be able to drive without the battery, the car might not let you on some grounds of preventing further damage.

[DiFortissimo]

Originally Posted by trollbait

it is possible to drive the Prius without gas, and people have done so

That was me!

Originally Posted by trollbait

I don't know what type of warnings the car gives the driver

Plenty! I stuck a (clean) gallon of gas in my (clean) lawnmower can, stuck it in the hatch and went out for my drive-'til-it-dies episode. I just wanted to know when it runs out, and what it does when it runs out.. Here you go:

1) you see the last dot (of 10) on the fuel gauge (around 50-75 miles left... YMMV)

2) the red GAS PUMP icon begins flashing

3) a rather rude, rhythmic BEEP is heard, after which the last fuel gauge dot flashes continually (approx 30-miles left)

4) the rude, rhythmic BEEP from above becomes a CONSTANT rude, rhythmic BEEP, melodiously accompanying the flashing fuel gauge light (about 15-or-so miles from death, as I recall)

5) A BIG, HONKIN' YELLOW EXCLAMATION POINT fills the display screen while all previous annoying activities continue unabated.

All I meant to say was, if intend to run a Prius out of gas, you'd better be good at driving during a DEFCON 7-level battery of disaster warnings. Having said that, I'll bet it's happened more than a few times, and the brain-dead teenage driver (or Al Gore's son [but I repeat myself], take your pick) probably said, "Nope, never heard a thing. Engine just DIED on me!"

My guess as to why Toyota tells you ABSOLUTELY DO NOT run it out of gas would be because, without the engine running, the traction battery could be drained down to complete discharge. Besides being bad for said NiMH battery (for which Toyota has to provide warranty), I don't think that, barring some dealer-provided intervention, the Prius could not be restarted. There's likely several other reasons, but I'll bet that one's near the top.

The "starter motor" is a giant 65-horsepower electric unit that can instantaneously turn the gasoline engine over at full idle speed. This is to mute the "bumpety-bump" you get with a regular geared flywheel starter, making the hybrid's mode-shifts a bit more transparent to the driver. Again, I'm speculating, but I don't see how-in-the-heck that little trunk mounted 12-volt flashlight battery could as much as TICKLE the huge 65-horse electric motor. (And yes, I know the big electric boat anchor runs, not on 12v, but from the traction battery's high-voltage. Just thought I'd say it to keep someone from correcting me needlessly. Y'see, I'm considerate like that.)

SIDEBAR:
My thoughts were, in case of an absolute out-of-gas emergency, to restart the engine with a dead traction battery could be accomplished by turning-on the car, then pushing it--in gear--for a ways. This would cause the off-throttle regenerative braking to charge the traction battery. I don't think this'll ever happen to me, but a plan deferred is no plan at all.

In my case, as SOON as the engine shut off, I pulled over, turned-off the car, put in my fresh gallon. Then I got back in, turned power-on and let it sit for a minute (for the electric fuel pump to pressurize the fuel rail), then repeated this on-off sequence. Finally, I pulled off and the engine started normally. All this may have been completely unnecessary but that's how I did it. However...

...it would not surprise me one bit to find that somewhere, deep in the ECUs black-box entrails, there is a little tell-tale Allargando-Ran-Me-Outta-Gas!!! error code being stored.

One's past often comes back a-haunting, but I'm hoping I dodged the No Warranty for YOU bullet. If not, I hereby dedicate my Prius as well as my own dead-of-a-non-warrantied-repair-heart-attack-stricken body to science 'cause, if it stored said code, and because of it, Toyota denies me warranty coverage on something, I'm gonna shoot the car and turn myself in for murder. And there ya go; two bodies for the price of one.

ADiF