What produces extactly 723 Volts?

[brblx]

What's wrong with "regenerative braking"?

That's exactly what it is. Braking that generates power to charge a battery rather than just burning it all off as heat.

call it 'regenerative engine braking' and i would have less issue.

the average consumer can't differentiate between 'engine braking' and actually braking with friction linings, though. that's why i don't like the phrase.

i've met too many people who actually think that the act of generating friction at the brakes is somehow charging their battery (and surprise, their hybrid struggles to get over 30mpg). service brakes will always 'waste' energy, it's decel under little to no braking that's going to help greatly with mileage (while no energy is 'free,' that's as close as you get in a car.)

we're basically to the point where it's going to be hard to increase mileage any further without pretty much having the computer drive the car for you (a general 'you,' as in, 'most.')

 

[brblx]

There always has to be a first.

lol, GM made it...15 years ago?

 

[JimKiler]

So per the OP the reason the electric car was killed in that documentary is because no one would buy it. Good thing the movie came out before we knew the facts, otherwise it would not have been nearly as intriguing.

 

[LTC8K6]

call it 'regenerative engine braking' and i would have less issue.

the average consumer can't differentiate between 'engine braking' and actually braking with friction linings, though. that's why i don't like the phrase.

i've met too many people who actually think that the act of generating friction at the brakes is somehow charging their battery (and surprise, their hybrid struggles to get over 30mpg). service brakes will always 'waste' energy, it's decel under little to no braking that's going to help greatly with mileage (while no energy is 'free,' that's as close as you get in a car.)

we're basically to the point where it's going to be hard to increase mileage any further without pretty much having the computer drive the car for you (a general 'you,' as in, 'most.')

Does the driver decide if regen braking will occur?

 

[ElFenix]

call it 'regenerative engine braking' and i would have less issue.

the average consumer can't differentiate between 'engine braking' and actually braking with friction linings, though. that's why i don't like the phrase.

i've met too many people who actually think that the act of generating friction at the brakes is somehow charging their battery (and surprise, their hybrid struggles to get over 30mpg). service brakes will always 'waste' energy, it's decel under little to no braking that's going to help greatly with mileage (while no energy is 'free,' that's as close as you get in a car.)

we're basically to the point where it's going to be hard to increase mileage any further without pretty much having the computer drive the car for you (a general 'you,' as in, 'most.')

from your post i'm not entirely certain if you know that engine braking is something entirely different from regenerative braking.

 

[brblx]

Does the driver decide if regen braking will occur?

no, that's all in the software for the ECM/PCM. but if you keep holding the gas down and then slam on the brakes at the last minute, you're not going to get much of a 'regen.' braking harder will not make it charge more- it'll make it charge less. but it's all up to the computer when to cut fuel to the engine and power up the stator for the generator (i'm assuming it doesn't stay powered all the time, unless they think that newton guy was full of shit).

 

[TakeNoPrisoners]

It is the same car as the chevy cruz that you can get for 20k. It is a massive rip-off.

The only way I'd get one is if it was free.

 

[brblx]

from your post i'm not entirely certain if you know that engine braking is something entirely different from regenerative braking.

i'm not sure that you understand how a hybrid works. but we may be misunderstanding each other, so let's try and be civil here...

edit: fwiw i'll go toe to toe with just about anyone when it comes to general car stuff. but i freely admit that i've never been to any hybrid training courses (usually the dealer will only send like one senior guy) and have garnered most of my information from the web, tech literature, and maybe some logical assumption. i know enough to take a hybrid apart (and put it back together) and generally know how it works; but i sure didn't write the software for the powertrain control modules on any of 'em...

 

[ElFenix]

i'm not sure that you understand how a hybrid works. but we may be misunderstanding each other, so let's try and be civil here...

edit: fwiw i'll go toe to toe with just about anyone when it comes to general car stuff. but i freely admit that i've never been to any hybrid training courses (usually the dealer will only send like one senior guy) and have garnered most of my information from the web, tech literature, and maybe some logical assumption. i know enough to take a hybrid apart (and put it back together) and generally know how it works; but i sure didn't write the software for the powertrain control modules on any of 'em...

engine braking being using the vacuum of the cylinders to slow the car down, regenerative braking being generating electricity from dynamos at the wheels to slow the car down

 

[brblx]

engine braking being using the vacuum of the cylinders to slow the car down, regenerative braking being generating electricity from dynamos at the wheels to slow the car down

i know what engine braking is. and i must have missed the 'dynamos at the wheels' on all the priuses that i've worked on.

generally, on a hybrid, the generator is between the engine and the trans. on some models i think they've integrated it into the trans itself. you're capturing energy from the wheels and just using it to turn a (central) generator (each output shaft may have its own, but they're not near the wheels) rather than a freewheeling engine (whether or not the hybrid system is able to charge without the engine spinning, i have no idea- it would be to its benefit). any drag on the driveline caused by the generator is a secondary effect...it's a system for charging the battery, not a system for helping you brake.

 

[Pheran]

what it is is not one, but two new places for energy to be lost- you're going to have to use electrolysis to get hydrogen, then use it to charge a battery, no? what the hell is the point, besides being able to carry around hydrogen slightly more effectively that you can a coal fired power plant?

Currently true, but maybe not when this artifical leaf goes commercial. Water + sunlight = hydrogen, pretty badass.

 

[brblx]

Currently true, but maybe not when this artifical leaf goes commercial. Water + sunlight = hydrogen, pretty badass.

that's pretty cool. wonder what the 'catalyst' is.

edit: oh, cobalt....so the real question is, how the hell hard is it to get mass quantities of cobalt?

 

[OVerLoRDI]

I imagine a more economical option would be to buy a cheap small engine car and get 30-40 mpg than spend all that money on a volt and "save" money at the pump. It is a statement car like the prius.

 

[ElFenix]

i know what engine braking is. and i must have missed the 'dynamos at the wheels' on all the priuses that i've worked on.

generally, on a hybrid, the generator is between the engine and the trans. on some models i think they've integrated it into the trans itself. you're capturing energy from the wheels and just using it to turn a (central) generator (each output shaft may have its own, but they're not near the wheels) rather than a freewheeling engine (whether or not the hybrid system is able to charge without the engine spinning, i have no idea- it would be to its benefit). any drag on the driveline caused by the generator is a secondary effect...it's a system for charging the battery, not a system for helping you brake.

ok, so i don't know where the motors are in a prius, big deal. any energy you capture from regenerative braking has to come from the car's velocity, so it does help slow the vehicle. wikipedia says this is a significant amount.

anywho, just from the context of the previous post i wasn't sure about your use of the term 'engine braking,' was all.

 

[Eli]

brblx, your understanding of regenerative braking is overall correct, however ElFenix is right - regenerative braking is braking; it slows you down significantly by itself. It converts the forward momentum of your vehicle into electrical energy to recharge a battery. This causes you to lose momentum and slow down.

It's something that we struggle to teach newbies in the Insight forums. If you're mashing the friction brakes, you're not doing it right.. lol. With the Insight, there are three braking mechanisms at work. Engine braking, regenerative braking and friction braking.

Engine braking is self explanatory and works the same way as it does with any car.

Regenerative braking is in addition to engine braking. It happens whenever you're decelerating with your foot off the gas. With the Insight at least, you do have a bit of control over it. If you're decelerating in say, 2nd gear from 40MPH, you'll get about 3kW of regenerative braking.

If you just barely touch the brake pedal, regenerative braking will go full, at around 5-8kW, depending on speed. This is like moderately stepping on the (friction) brakes, and slows you down at a fair rate.

Then if you need to stop more quickly, you can press the brake pedal down further. Regenerative braking stays full, but the friction brakes begin to engage.

Ideally, you would never use your friction brakes. Obviously this is impossible, but with careful driving it can be hugely mitigated. I only use my friction brakes for the last ~10MPH of a stop, unless something has happened and I wasn't able to anticipate the stop.

Consequently, I'm still on my original brake pads at 160,000 miles. Using all three braking methods, it is very easy to modulate your speed. If you fly up to a light and hit your brakes at the last second in a hybrid, you're doing it wrong.

 

[brblx]

brblx, your understanding of regenerative braking is overall correct, however ElFenix is right - regenerative braking is braking; it slows you down significantly by itself. It converts the forward momentum of your vehicle into electrical energy to recharge a battery. This causes you to lose momentum and slow down

stopped reading here since you obviously did not read my post; making that statement and i'm assuming all that follow completely needless.

i didn't saying regen braking didn't slow the car down. i said that the PRIMARY EFFECT is to charge the batteries, as that is the only time that the power produced (notice the past tense) by the engine is not being utilized for a different purpose. toyota is not trying to help your prius brake, they are trying to help your fuel economy. your argument is basically that because my car has a manual, the message center should automatically say 'hill descent mode' when i go down hills in low gear.

edit: ok i caved and read your post. you're agreeing with me on the use of regen braking- ideally (in an energy conservation sense), you want the car to roll as long as possible at speed without throttle input.

but yet again people want to pick fights based around semantics and escalate them into arguments where no one disagrees.

 

[LTC8K6]

IIRC, the Prius brakes using only regen braking unless certain conditions are met that require friction braking.

Going too slow for regen to be effective, battery full, loss of traction, panic stop, etc...

That is, the Prius is braking using regen most of the time.

 

[bfdd]

should be pushing diesel hybrids, duh. want to stop using ME oil, that's the best start. then we can make all the diesel we want from tar sands in Canada and shale from down here. Build up the nuke plants to offset the energy demand of coal. We'd be good, to bad people want instant gratification.

 

[marvdmartian]

So even though GM claims to have "sold" almost 3900 of these turkeys, there's still TWO THIRDS of them on the dealer lots?? Sounds like they've been taking lessons in accounting from government budget savings analysts!!

Hey GM, here's your clue. The Volt is overpriced by at least 30 to 40 percent, and is NOT worth the premium price tag you've placed on it. Compared to so many other vehicles with similar mileage, your model is undervalued to the point of ridiculousness! When the calculations (that I've made) show me that, in order to break EVEN with my mid-sized sedan, I would have to own your vehicle for over 12 years (and suffer ZERO major breakdown costs, including replacement of the expensive battery pack), then your car is nothing more than a PR joke! :thumbsdown:

 

[Eli]

stopped reading here since you obviously did not read my post; making that statement and i'm assuming all that follow completely needless.

i didn't saying regen braking didn't slow the car down. i said that the PRIMARY EFFECT is to charge the batteries, as that is the only time that the power produced (notice the past tense) by the engine is not being utilized for a different purpose. toyota is not trying to help your prius brake, they are trying to help your fuel economy. your argument is basically that because my car has a manual, the message center should automatically say 'hill descent mode' when i go down hills in low gear.

edit: ok i caved and read your post. you're agreeing with me on the use of regen braking- ideally (in an energy conservation sense), you want the car to roll as long as possible at speed without throttle input.

but yet again people want to pick fights based around semantics and escalate them into arguments where no one disagrees.

I was agreeing with everything you had said except the misnomer thing. I was just trying to elaborate.

The purpose of regenerative braking is braking. That's why its called regenerative braking. It's just that instead of wasting the energy as heat, it tries to recapture and store some of it.

Regenerative braking is by nature a system to help you brake. The drag on the drivetrain is a direct result of converting kinetic energy into electricity.

It serves the same purpose as friction brakes. Theoretically, an electric car could do away with friction brakes all together. A motor acting as a generator is perfectly capable of locking the wheels if it was designed to do so.

Look at it this way; if you replaced the battery with a large resistor in a regenerative braking setup, you would still be wasting the energy as heat just like with friction brakes. You wouldn't be regenerating anything, but you would still be braking with the generator.

The only thing I disagreed with was your statement that regenerative braking is a misnomer. It is not.

Edit: Helping your fuel economy is the after effect, not the braking itself. Theoretically, a regenerative braking system could charge your 12V battery. This wouldn't manifest itself as increased fuel economy, but it would still be regenerative braking.

I was not trying to argue with you at all, I was trying to have a discussion about something that is part of my every day vocabulary and that I'm quite familiar with.

 

[brblx]

right, but when i explained i said it's a misnomer to THE COMMON CONSUMER who now thinks that braking = gas mileage. perhaps people just aren't this dumb where you live.

 

[Eli]

right, but when i explained i said it's a misnomer to THE COMMON CONSUMER who now thinks that braking = gas mileage. perhaps people just aren't this dumb where you live.

Ah, well I would agree with that. Most people don't understand the concept of regenerative braking at all... but I blame that on the education system, not Toyota or the term "regenerative braking".

 

[ElFenix]

the real problem here is that everyone on the internet (myself included) thinks a long reply is a rejoinder rather than an elaboration


people must be dumb where you live brblx

 

[brblx]

i live in tennessee, take a guess.

 

[brblx]

Edit: Helping your fuel economy is the after effect, not the braking itself. Theoretically, a regenerative braking system could charge your 12V battery. This wouldn't manifest itself as increased fuel economy, but it would still be regenerative braking.

I was not trying to argue with you at all, I was trying to have a discussion about something that is part of my every day vocabulary and that I'm quite familiar with.

charging your 12v battery would still increase fuel economy, assuming that the current to the stator in the 12v generator can be managed effeciently enough (otherwise the energy savings would just go into having an extra-well-charged battery).