"Extra Mild" Hybrid?

Since people tend to avoid stops at all costs here and components like A/C require the engine to be running, there is very little benefit.

Also, notice how much City MPG is disregarded? All the marketing focuses on Highway MPG, which doesn't benefit in any way from start/stop.

 

And lead battery too.

 

That's due to their emissions laws in europe. You can actually get a fine if you sit at a stop light for too long without turning off your engine. This is due to most of europe still using diesel engines in most cars. However, today, it's about a 50/50 split between petrol and diesel car purchases lately, due to better tax breaks for cleaner emissions vehicles.

At least that's what my coworker from belgium told me. They were surprised to see everyone idling their engines for so long without shutting it off. They actually said you would be considered rude over where they live.


But to the OP, an alternator only puts out 13-15v, they also have some 24v alternators on larger vehicles. But either way that's relatively low voltage. Motors like a starter are usually refferred to in HP or KW. So lets just say you have a 15KW motor, 15,000 watts divided by 24v, is about 625amps. That's a lot of freaking amps to try and sustain for any long period of time. The heat dissapation in the electrical wires, even internally will be very hot. This will also require a significant amount of battery capacity to sustain, it's just not feasible to do other than a quick start/stop. You really need a high voltage capable mild hybrid like the prius, something with a direct shaft or drive chain connected to the wheels that can produce high voltages. With higher voltages, you can have a smaller capacity battery pack, have lower amperage in the system which gives you the ability to go with a higher KW motor.

Ideally for what you're saying, the IMA from honda is the best solution. Subaru also has a similar integrated motor on their new XV crosstek hybrid. These cars will be the mildest you can get and not just be a start/stop hybrid.

 

Yes they are. FAR off.

A conventional starter draws anywhere from twice to 4 times the current that an alternator is capable of handling.......and one is DC and the other is AC. The old generators would be closer but still WAY off capacity wise.

You sound like a very inquisitive guy. Have you considered taking some courses at a local Junior College......just for the fun of it ? It might be a really good experience. Basic electronics or electricity might be a good place to start.

 

Systems quite similar to what Greg suggests are already available today.

i-ELOOP Mazda6 Coming As 2014 Model - HybridCars.com

 

A start and stop system improves a lot the official city mileage in the unrealistic european official test cycle, so manufacturers can put a greener sticker on the car and in some countries this also leads to less taxes for the buyer. In the more realistic US test cycle, start and stop gives just a tiny improvement, so manufacturers would have no gain putting it into cars, just more costs.

 

I wouldn't call that a hybrid at all. It's more like a system to reduce the parasitic loss of the alternator. The gains will likely be similar to that of how everyone has gotten rid of their power steering pumps in favor of electric power steering.

 

Well, Toyota just announced their new high mileage non-hybrid vehicle. It uses the Atkinson technology of the Toyota hybrids without the hybrid part. In a very small car. Rated at about 70 MPG. So low cost, great mileage. Not sure if we'll see it in North America though. It'll be interesting to see how they modified it so it can get moving from a stop.

 

Probably more for countries like India, where crash scores don't matter because most likely you'll be hitting mopeds. Acceleration is also likely similar.

HTC One_M8 ?

 

Are you implying Moped-like acceleration (wink,wink)? Why, I believe that you are!

 

The car is actually for Europe initially. To compete with the diesels, but without the smog/particulates.

Toyota unveils new generation of fuel-efficient engines

 

Don't be fooled by some quotes by people. The engine we have and that is in the new Toyotas is not -really- an "Atkinson" engine. It's an "Atkinson like" engine. Nobody could afford a -real- Atkinson engine, nor could any vehicle bear the weight of it! Due to modern engines relying on so much electronics controlling the engine parts we can now have most of the benefits of the Atkinson engine without the extreme disadvantages of it, such as complexity and weight. I like to call it an "Atkinson cycle" engine, as you called it.

Back to topic, I see several offerings of "start-stop technology" appearing, including from Kia. Optional, of course.

 

I do believe the new Rio/Accent was supposed to be released with start/stop capability. It never panned out, though.

 

Because our gasoline is too cheap.

 

There a few non-hybrid tricks in the Honda Civic Hybrid used to improve mpg:

1. 2 spark plugs per cylinder, with offset spark timing. Sort of a one-two punch for igniting the mix.

2. Dual lift cam lobes. Actually two lobes, and the car shifts from one to the other with hydraulics. Usually the lower lift lobe is used; only under heavy acceleration demands is the high lift lobe shifted over.

3. Extensive use of weight reducing aluminum, for suspension components and so on.

One of the cornerstones of stop-start technology is the hybrid battery and electric motor being used to deal with the repeated start ups. If instead you're using the 12 volt battery and a traditional starter, something is going to need beefing up, or there needs to be some innovation in how the start ups are accomplished.