A peek at the future :
At Johnson, much of the excitement revolves around the promise of how better batteries could fuel a new generation of cleaner cars, which could help reduce America's dependence on foreign oil. In a garage off the back of the lab, senior VP Mary Ann Wright keeps a Ford Escape Hybrid, which she engineered while working at Ford. When she arrived at Johnson Controls, she and some co-workers replaced its nickel-metal-hydride batteries with lithium-ion. The old batteries weighed 192 pounds versus 130 pounds for the new ones, which yield more power. The result: her jury-rigged Escape gets off-the-charts mileage.

Source:http://www.newsweek.com/id/170341/page/2

If my memory serves me correctly, one of our posters, a journalist, (Rich) reported Johnson Controls approached Ford Motor Company at last year's Detroit Auto show about providing an aftermarket swap ($3000?) that included a software upgrade. Net result was reported at 30% improvement in fuel efficiency.

Did Johnson Controls appear at this years (2008) hybridfest with a FEH with this hybrid battery swap and a reported 42 mpg @65 mph?

 

I was at Hybridfest for 1 day only, but IIRC, Johnson Controls was there with a Lithium Ion FEH on display.

When I asked how many kWh the pack had, they said "same as the stock one".

So what's the benefit? Very slight IMHO.

A) slightly lower weight
B) no A/C cooling required
C) better cold weather performance

So the benefits won't come from more EV time or more "power".
The benefits come from less "parasitic loss" from running the A/C for cooling, and less cold weather losses.

This type of pack is meant as a replacement if/when the stock one finally wears out.

 

Isn't it possible that the Johnson Controls Li Ion battery can be used over a much broader state of charge range than the oem NiMH battery? If that's true, the useable capacity of the Johnson Controls battery could exceed that of the oem battery by quite a bit.

 

Yes the Lithium-ion hybrid battery would have a larger SOC rating. However, durability--150,000 miles or longer--issues are still being researched. Cost of these hybrid batteries remains problemsome at this time frame. EnerDel out of Indianapolis has claimed they will be providing lithium-ion batteries to auto makers in 2009 but this is the non-PHEV version.

 

I agree with you for the most part... however... the weight should be fairly significant. In my work with them LiIons have a higher energy density per unit weight.... actually volume wise there isn't much difference most of time. Its the weight difference that is the biggest thing. Add to that the loss of the A/C weight and it should be a fair bit. Not enough to boost the MPG by 10's but probably by single digits.