http://www.news.com/8301-11128_3-9903014-54.html
This shows the conundrum of tweaking an already fuel efficient vehicle. In absolute terms, it doesn't save a lot. But as an architecture, a map for inefficient vehicles, it makes a lot of sense.

My personal belief is a plug-in makes more sense if we just "tickle charge" the existing batteries. What I'm suggesting is the Prius control laws and bringing the battery to a maximum charge, slowly, safely, would make sense. It won't give a terrific improvement but it wouldn't cost much either. But over time, the savings would add up and it would become cost effective quickly.

Bob Wilson

 

Another case of needing to differentiate between R&D and production. Conversions at $15,000 are never going to make sense. When the plug in option is $2000 it starts to make a lot of sense. And cars like the Escape Hybrid will make sense as a plug in before cars like the Prius.

 

Have they speculated on the cost for a factory built plug in and the ROI it would have? If they were to put them into production obviously the cost shouldn't be any more than a regular vehicle.

I haven't looked into the plug in vehicles yet but do they have a regenerative system that works through the brake system?

 

I don't see the issue of converting hybrids to plug ins. The future will be replacing non hybrids with plug ins when people replace their worn out or gas hogs with more fuel efficient cars.

Two changes I would like to see is the trickle charge option and a engine off cold start.

 

There is a "genius" in Indiana who has hacked the Prius software and built a plug in hybrid using the standard hybrid battery pack. Bob, this is your type of guy--if you haven't made contact with him yet--for your adventures. I'm on a dial up--away from home- and I can't search too well to relocate this individual.

 

I think plug-ins will be best for tiny-sub compacts.

#1 if you have a light car, you need fewer horsepower
#2 you need fewer batteries ( fewer kWh )
#3 you can charge with standard 120v AC

The fact is, battery weights, even Li-Ion, add up quickly.
Use the space shuttle as an example. You use 2 million pounds of fuel to carry 7 passengers and 2000 pounds of cargo. At some point, you are adding batteries just for power to carry around the batteries!

Also, you can't get much power out of a standard 120VAC outlet.
With smaller cars, the standard outlet becomes practical.

It takes about 11-12 hours to recharge a 50 mile Plug-in Escape with 120vAC. In other words, it takes many hours of input, for a short amount of output. Look at gas. 5 minutes of input = 500 miles of output.

With small, light cars, we can get close to a 1:1 ratio.
4 hours of charge to 4 hours of drive would be nice.
-John

 

As an afterthought, while less practical, you could have 3 or 4 sub packs in a larger car. You could use 3 or 4 separate 120vAC cords to your car and charge each sub-pack from it's own circuit. Then you could charge an Escape size car in 4 hours. But who wants 4 cords? I know a few people wouldn't mind... I think the majority would....

 

Bother! Why mess with four cords. If you're gonna do that just go out and get a 50 or 60 amp appliance cord and plug. Using four 15 amp chords would create all sorts of problems. Peeps tring to plug two of them into the same 15 amp domestic circuit, either at home or away, use of non-grounded, or under-rated extension chords - some long with lots of loss and use of extension chords outside in wet conditions.

 

GPS, I don't think the charge time is such a problem. The thinking we have to change is the "one concept does everyhting" situation that we actually have with conventional cars (except that the gas mileage is so bad). For our FEH, plug in time wouldn't be an issue. Except for a few trips a year, it's in the garage from 7 or 8 PM until 9 AM or noon the next day. Then it's driven on various short trips amounting to less than 50 miles. I would guess most people would have at least one car in this category. On the other hand, my truck isn't home at all a lot of nights and get's it's miles in sporadic longer trips. In other words, I need a diesel.

 

I'm firmly convinced that PHEVs will be a small niche if that. For me personally I wouldn't invest in one as a premium over the current Prius because with a 150 mi RT commute I'd only get 20 'gas-free' miles if the initial statements are right. That means that daily I'd save about 1/2 a gallon at current technology. Instead of 3 gal / day I'd end up using 2-1/2 gal. That would be a 15-20% total savings in fuel daily and annually.

The premium would have to be very very small for me to consider giving up the 'traditional' hybrid. OTOH my wife has a 24 mi RT commute each day and she'd be a perfect candidate for one. As long as it looked pretty and had a convertible top. LOL