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Old 29th March 2009, 11:10   #1
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Default Micro Hybrids?

Hi All,
Posting after a real long time. Mahindra has started to offer a Micro-Hybrid/Start-Stop kit akin to ones found in Mercs and BMWs(here) in their top of the Line VLX and Tata has been talking about Micro-Hybrid on the Nano and other cars in their line up.

According to sources, the Start-Stop kit on the Scorpio only costs about 3.5K extra to build.

My perceptions are that Micro-Hybrid will eliminate the existing starter motor with a More powerful Belt driven motor-alternator(instead of the alternator), they would need an upsized battery(to run the accesories) and would replace the AC Fan/Radiotor with a mechanism similar to Home AC's(one motor running the fan as well as the Compressors). Most other hardware required for this kind of hybrid is already present in the cars(like clutch depresssion sensors and In-gear sensor). Ofcourse this would require rewiring. Is there some thing i missed?


Since we already pay extra for BS-III systems(in some cars) for cars sold in Cities, why not make this system compulsory too? After all we do idle the car about 60% of our journey(in Cities). When will we start seeing Start-Stop system on every model as a standard(not optional)?

Also, Is there any one out there owing the Micro-Hybrid version of the Scorpio? Any inputs on the same?
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Old 29th March 2009, 15:10   #2
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There is nothing *hybrid* about the Mahindra Scorpio, they are only abusing the term. An engine start - stop system does not a hybrid make. Else every taxi on the roads will qualify for the title of a manual-hybrid (manual because taxi drivers follow the same practice).

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My perceptions are that Micro-Hybrid will eliminate the existing starter motor with a More powerful Belt driven motor-alternator(instead of the alternator), they would need an upsized battery(to run the accesories) and would replace the AC Fan/Radiotor with a mechanism similar to Home AC's(one motor running the fan as well as the Compressors). Most other hardware required for this kind of hybrid is already present in the cars(like clutch depresssion sensors and In-gear sensor). Ofcourse this would require rewiring. Is there some thing i missed?
AFAIK, Mahindra's stop / start system only has a stronger starter and more powerful battery.

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Since we already pay extra for BS-III systems(in some cars) for cars sold in Cities, why not make this system compulsory too?
How about because not everyone wants it? I can only imagine how ANNOYING this system will be in stop-go traffic.
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Old 29th March 2009, 15:24   #3
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Quote:
Originally Posted by arunmur View Post
Micro-Hybrid will eliminate the existing starter motor with a More powerful Belt driven motor-alternator(instead of the alternator), they would need an upsized battery(to run the accesories) and would replace the AC Fan/Radiotor with a mechanism similar to Home AC's(one motor running the fan as well as the Compressors).
Not so. AFAIK, the so-called Micro Hybrid system by Mahindra only cuts out the engine if it idles for 10 seconds on neutral, and restarts it when the clutch is depressed to engage a gear. The alternator does not continue to work as a motor drawing power from the battery, and the AC compressor does not keep running (albeit the cabin blower does). There is also a selector switch on the dash to allow the driver to turn off/turn on the Micro Hybrid system.

I wouldn't use such a system in stop-start traffic/in summers, because it could get irritating, and I wouldn't do without my AC in 45*C in Delhi when stopped at a traffic light, and fuel consumption be damned. That said, the Micro Hybrid system is only being offered with Mahindra's BS-IV Scorpio, and I'd prefer to buy a BS-IV vehicle rather than BS-III.
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Old 29th March 2009, 16:09   #4
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Originally Posted by GTO View Post
There is nothing *hybrid* about the Mahindra Scorpio, they are only abusing the term. An engine start - stop system does not a hybrid make.
+1 to that. Its just a beefed up starter motor/ alternator combination. There is no electric motor in the drive train, so it cannot qualify as an hybrid, micro or otherwise.

Having said this, if it does result in some fuel savings, it might be worth the extra 3.5K or so, provided its not very irritating in real life conditions. Leaving the hybrid hype aside, Mahindra need to be lauded for coming up with this device.

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Originally Posted by arunmur View Post

would replace the AC Fan/Radiotor with a mechanism similar to Home AC's(one motor running the fan as well as the Compressors). ?
The home ACs have different motors for the fan and the compressor (this one is hermetically sealed) and it would have to be the same for car ACs.
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Old 29th March 2009, 16:26   #5
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Ok, Thanks for the insights as to how it is implemented.

Only thing i see missing is the AC compressor running from electric power, which means a much bigger battery.

If the AC works too, I guess its not that annoying?

That said, here is the Micro-Hybrid from Smart.


Another possible more 'Intelligient' solution could be to store the compressed A/C gas in a small tank(near the pressure regulator valve) to release while the Compressor cannot be run(cutting cost on bigger battery, alternator and many mechanical components). The compressor and the alternator can be made like in BMWs to run full while the car is decelerating.
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Old 30th March 2009, 21:32   #6
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I came across a Micro hybrid Scorpio. The system used is very simple. it has a normal starter motor with enhanced bushing for increased cycle of operation and a battery with increased AH. Other than that there is a Electronic unit that switched off and on as per its algorithm. It has sensors to sense clutch engagement ,neutral position, vehicle speed engine RPM etc.

The engine switches off completely so there is no chance that your AC would work.

This feature is fairly useful in city conditions. Its ability to reduce pollution depends on the cycle of operation i.e. the frequency of switch on / off.

"Hybrid" is something which uses more than one sources of energy. Like a Engine(Fuel)/Motor(Battery) OR Engine(Fuel)/Motor(Fuel Cell). "Micro-Hybrid" is definitely not a HYBRID.
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Old 31st March 2009, 10:50   #7
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We should thank mahindra for at least providing the option. Unless it is used and tested in INDIA , how can we decide if is useful or not?


The regenerative breaking is one more thing that should be provided on Indian road.


If these technologies are good then they can become next must have on all the Indian cars, If they are not , they will die. As simple as that :-)

But for this to happen they should be first offered on indian road with indian price ( Not like price for AIRBags we are paying in india)
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Old 4th August 2010, 14:26   #8
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Default Discussion about the Start Stop "Micro Hybrid" Technology

I had a query in my head about the the Start Stop "Micro Hybrid" Technology that is available on the scorpio here in India and other cars abroad... The technology is by Bosch.

Although this appears to be successful and a growing trend, I cant fully understand the benefits, if any.

Now if I understand the system correctly, the engine shuts off automatically in neutral and starts when the accelerator is pressed. After the additional initial cost, the claim is 5 to 10 % reduction in Fuel consumption. My queries are below:

1) What happens when the A/C is on? Can the A/C function without the engine? If you use the aircon, does the engine shut down in neutral??

2) Most Common Rails has glow plugs and these glow plugs take about 2-3 seconds to warm up before one is supposed to start the engine. In the Start Stop system, are the glow plugs not required or is there a 2-3 second lag between when you press the pedal and when the engine actually starts?

3) Doesn't the frequent start - stop cause excess wear and tear on the engine. I remember reading somewhere that frequent starting/stopping is bad for the engine.

4) Wont the frequent startup/shutdown damage the turbo in diesel cars?

5) The starter motor/battery is obviously beefed up, but still if the motor is used 100's of times daily (in our traffic jams) what will be the motor life/battery life? Replacement cost will obviously be higher than normal due to the heavy duty nature. Wont this nullify any savings in fuel?

6) Is there any real environmental impact? There might be some saving in the fuel, but what about the environmental impact of manufacture and disposal of the heavy duty battery, starter motor etc??

Obviously a MNC like Bosch cant be wrong, so what am I missing?

Last edited by AbhiJ : 4th August 2010 at 14:33.
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