whaaaaaaaaaaaaaaaaaat? Mercedes invest in radical electric car technology which could revolutionise the industry

[leadeater]

48 minutes ago, Zodiark1593 said:

The 2nd video is actually an automatic transmission with manual gear select mode. The underlying technology is still the traditional planetary gear transmission with torque converter. Not exactly the same thing. My sister's 2003 BMW has the same thing, though tbh I can make downshifts much faster in my manual Mazda than that thing.

I find the Jatco JR710E in my car very reasonable for an auto with gear selection. The early transmissions of this type were pretty bad but they have gotten better, terrible ones still exist though.

 

I do have to wonder how much more expensive DCT transmissions actually are, seems to me they should really be standard now.

[Zodiark1593]

32 minutes ago, leadeater said:

I find the Jatco JR710E in my car very reasonable for an auto with gear selection. The early transmissions of this type were pretty bad but they have gotten better, terrible ones still exist though.

 

I do have to wonder how much more expensive DCT transmissions actually are, seems to me they should really be standard now.

Well, you have the obstacle of many people on the road having the habit of creeping forward slowly in heavy traffic. This habit will kill a DCT clutch fairly quickly. A traditional auto will not wince though, despite the crappy fuel economy you get from doing so.

[ionbasa]

2 hours ago, Implosivetech said:

There are the modern combinations, where they can shift into a position, and then either with buttons on the clutch, or moving the clutch slightly up and down, shift the gears.

 

Like these:

 

The first video you linked is a true manual transmission. The second video is just an automatic transmission that lets users select their desired gear ratio instead of letting the computer do it. The transmissions are still different. 

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How about we get back on topic? Regarding the use of supercapacitors in the Mercedes car: It's not a bad idea, there are technical issues to overcome, such as the transient response to discharging, where caps discharge their energy logarithmically throughout the time scale. If Mercedes has found a solution to that that other super-cap manufacturers haven't found, it would be interesting to know the details. 

 

I imagine what is happening in this situation is that Mercedes has charging and regen braking hitting the supercaps first and then back feeding into the lithium battery bank vi a bidirectional dc to dc converter. Otherwise, the caps would always stay energized if just in parallel with the battery and their are both advantages and disadvantages in that setup. The BMS (Battery Managment System) will let as much current to the lithium ion backs allowable, so dumping a $h*t ton of current into lithium ion packs (pouch cells) is possible if done properly, ie: liquid cooling, BMS with large enough bypass resistors, temp monitoring, etc.

[Zodiark1593]

6 minutes ago, ionbasa said:

The first video you linked is a true manual transmission. The second video is just an automatic transmission that lets users select their desired gear ratio instead of letting the computer do it. The transmissions are still different. 
 

---

How about we get back on topic? Regarding the use of supercapacitors in the Mercedes car: It's not a bad idea, there are technical issues to overcome, such as the transient response to discharging, where caps discharge their energy logarithmically throughout the time scale. If Mercedes has found a solution to that that other super-cap manufacturers haven't found, it would be interesting to know the details. 

 

I imagine what is happening in this situation is that Mercedes has charging and regen braking hitting the supercaps first and then back feeding into the lithium battery bank vi a bidirectional dc to dc converter. Otherwise, the caps would always stay energized if just in parallel with the battery and their are both advantages and disadvantages in that setup. The BMS (Battery Managment System) will let as much current to the lithium ion backs allowable, so dumping a $h*t ton of current into lithium ion packs (pouch cells) is possible if done properly, ie: liquid cooling, BMS with large enough bypass resistors, temp monitoring, etc.

Honestly, I would like to see Hybrid designs that utilize capacitors. Engines such as the Rotary, or a turbine engine are small, and quite efficient at high rpm (very inefficient much lower however), and can easily run on a wide variety of fuels with minimal modification. The engine would then work to keep the capacitors full, while the capacitors work to send power to the drive motor(s) on a moment's notice. If the capacitors can sustain the drive motor for even just a few seconds, that should prove sufficient to give the engine time to ramp up. And a small Li-Ion battery would be used to power auxiliaries.

 

Though I'm not an engineer, so for all I know, this could just be a disaster waiting to happen.

[ionbasa]

2 minutes ago, Zodiark1593 said:

Honestly, I would like to see Hybrid designs that utilize capacitors. Engines such as the Rotary, or a turbine engine are small, and quite efficient at high rpm (very inefficient much lower however), and can easily run on a wide variety of fuels with minimal modification. The engine would then work to keep the capacitors full, while the capacitors work to send power to the drive motor(s) on a moment's notice. If the capacitors can sustain the drive motor for even just a few seconds, that should prove sufficient to give the engine time to ramp up. And a small Li-Ion battery would be used to power auxiliaries.

 

Though I'm not an engineer, so for all I know, this could just be a disaster waiting to happen.

IMO the rotary is an bygone engine, it was cool and different while it lasted and I applaud Mazda for their feat in putting it in production on their vehicles with the Wankel Engine. Turbine engine would be interesting too. Personally, I'm keeping an eye on Mazda's new "sparkless engine"; see: http://www.foxnews.com/auto/2017/08/09/mazda-introducing-breakthrough-sparkless-gasoline-engine-in-2019.html (I know, I know, its Fox, but it's an Autos column), its an HCCI (gasoline) engine which touts better power with 20 to 30% efficency. 

 

Hybrids like what you describe are used in locomotives, sans the supercaps. They couple the diesel engine to a generator, and then drive the wheels with electric motors (and a transmission). Hybrid locomotives also exist and are fairly new and still being adopted, they use a system almost exactly like what you describe. 

 

The locomotive approach is called a series hybrid, automakers on the other hand are preferring parallel hybrids, where the ICE and motors are both coupled to the drive wheels. Series Hybrids can work in vehicles, there is one car that I know of that has done this first: https://en.wikipedia.org/wiki/Fisker_Karma MPG was pretty respectable: 55/54 with 300 mile range; but it is also an older car from 2012, there is supposed to be a 2017 model year successor. Otherwise, the technology you are refering to is called "EREV": extended-range electric vehicles. The topology looks like this: 

 

The only other two production cars that have this (and are affordable to consumers) is the Chevy Volt or the BMW i3 with APU option. 

 

As to why more vehicle manufacturers aren't taking this approach: probably petroleum companies "sponsoring" them not to do so (my personal conclusion from what i've read and seen in industry). There was actually a discussion about this on an internal SAE member forum and it got quite interesting. I wish I could share .

[Zodiark1593]

1 minute ago, ionbasa said:

IMO the rotary is an bygone engine, it was cool and different while it lasted and I applaud Mazda for their feat in putting it in production on their vehicles with the Wankel Engine. Turbine engine would be interesting too. Personally, I'm keeping an eye on Mazda's new "sparkless engine"; see: http://www.foxnews.com/auto/2017/08/09/mazda-introducing-breakthrough-sparkless-gasoline-engine-in-2019.html (I know, I know, its Fox, but it's an Autos column), its an HCCI (gasoline) engine which touts better power with 20 to 30% efficency. 

 

Hybrids like what you describe are used in locomotives, sans the supercaps. They couple the diesel engine to a generator, and then drive the wheels with electric motors (and a transmission). Hybrid locomotives also exist and are fairly new and still being adopted, they use a system almost exactly like what you describe. 

 

The locomotive approach is called a series hybrid, automakers on the other hand are preferring parallel hybrids, where the ICE and motors are both coupled to the drive wheels. Series Hybrids can work in vehicles, there is one car that I know of that has done this first: https://en.wikipedia.org/wiki/Fisker_Karma MPG was pretty respectable: 55/54 with 300 mile range; but it is also an older car from 2012, there is supposed to be a 2017 model year successor. Otherwise, the technology you are refering to is called "EREV": extended-range electric vehicles. The topology looks like this: 

 

The only other two production cars that have this (and are affordable to consumers) is the Chevy Volt or the BMW i3 with APU option. 

 

As to why more vehicle manufacturers aren't taking this approach: probably petroleum companies "sponsoring" them not to do so (my personal conclusion from what i've read and seen in industry). There was actually a discussion about this on an internal SAE member forum and it got quite interesting. I wish I could share .

In a luxury car, having a level of smoothness in the engine is necessary. The rotary is smooth while having a high power/weight ratio, hence my suggestion. Though it is no longer used for reasons (such as the fact that they devour oil, and the complex seals, etc, etc). A turbine would be better. While potatoes at low rpm, in a series hybrid, this disadvantage should be completely overcome. Heat would be a significant obstacle however. I've read stories of turbine powered motorcycles that would melt the front bumpers of cars that came too close to the exhaust. In an enclosed area, I would imagine the heat to be a potential problem for adjacent components.

 

I like the use of capacitors as they can provide a monstrous amount of current at a moment's notice without needing to be overly large. I feel this would be a good approach with the goal of reducing weight, and would lay the ground work for more advanced, fully electric vehicles in the future. Only the power supply should need to be swapped.

[BlueChinchillaEatingDorito]

6 hours ago, leadeater said:

Yet all the issues he is pointing out at the time stamp are exactly the same with any car, full electric or non at all. So I don't see how this is specifically a down side to Tesla's or electric cars.

The downside is that this happens at a much rapid pace to all electric cars, luxury or not. With an electric car, you're practically guaranteed for it to require a major repair 3-4 years down the road due to the battery degrading. With a conventional petro, diesel, or even hydrogen powered vehicle, this isn't much of an issue because the fuel tank does not degrade in terms of capacity over time. It's very rare for any modern conventional petro or diesel powered vehicle to require a major repair in the first 5 years of ownership. 

 

6 hours ago, leadeater said:

Then at the time of battery replacement you could just buy another newer used Tesla.

Why would you buy used Tesla? No dealer is going to replace the battery before they sell it. They would literally be bleeding out any margin that could've been made. So you're literally just buying a used car, then flipping it after 2 years. 

[leadeater]

8 minutes ago, BlueChinchillaEatingDorito said:

The downside is that this happens at a much rapid pace to all electric cars, luxury or not. With an electric car, you're practically guaranteed for it to require a major repair 3-4 years down the road due to the battery degrading. With a conventional petro, diesel, or even hydrogen powered vehicle, this isn't much of an issue because the fuel tank does not degrade in terms of capacity over time. It's very rare for any modern conventional petro or diesel powered vehicle to require a major repair in the first 5 years of ownership. 

 

Why would you buy used Tesla? No dealer is going to replace the battery before they sell it. They would literally be bleeding out any margin that could've been made. So you're literally just buying a used car, then flipping it after 2 years. 

The batteries don't need replacing in 3-4 years though and all Tesla's have an 8 year unlimited range warranty on them with 70% capacity, this warranty transfers to new owners.

[piemadd]

On 9/18/2017 at 2:09 AM, leadeater said:

The batteries don't need replacing in 3-4 years though and all Tesla's have an 8 year unlimited range warranty on them with 70% capacity, this warranty transfers to new owners.

If they wanted to buy over tesla owners, they would probably have to make the warranty for 8 years

[TheMcSame]

"Their new developments in the technology has also now just got a $60 million backing from Mercedes parent company Daimler,"

 

So... Not Mercedes... 

 

On a more serious note though... I'll believe it when I see it. Battery tech has a funny habit of being discovered and never getting anywhere....

[piemadd]

21 hours ago, TheMcSame said:

"Their new developments in the technology has also now just got a $60 million backing from Mercedes parent company Daimler,"

 

So... Not Mercedes... 

 

On a more serious note though... I'll believe it when I see it. Battery tech has a funny habit of being discovered and never getting anywhere....

Yeah. The closest we have to this is on the GooglePixel, which charges in less than 20 minutes.