What is the real difference? I mean i understandyou plug the car in at night or whatever. where the one's we have generate the power by regeneration and stuff. but is it only battery size the difference? Why do they get over 100mpg and ours squeeking out just over 30?

 

Because the lithium-ion batteries allow you to run exclusively in EV for the first 50 miles...then use the ICE for the rest of the day. Charge over night. Repeat.

 

The lithium ion batteries are much more efficient than the nickel metal hydride batteries that we have, and they allow a PHEV to get that wicked high mileage even if there's an onboard gasoline generator running part of the time. The problem with most Li ion batteries right now is that the batteries heat up, sometimes to the point of combustion (ouch), and car makers are promising fixes to that for all the PHEVs promised for 2010. Our NiMH batteries don't explode but they aren't nearly as efficient. THe 'plug-in' part of the PHEV just right delays the kick-on of the onboard generator (as least from the perspective of commuting around some of there huge Texas cities here).

 

One difference not yet mentioned--and this is from GPSman1--our current hybrid battery unit has 250 D-cell sized batteries. The Hybrid-Plus lithium ion battery pack has 1600 D-cell sized batteries. From what we have read from GPSman1's post these new lithium ion batteries do not heat up with usage and thus, there is no need for the cooling fans and heating element in our current hybrid battery pack. This results in "free" space and thus, additonal room for more lithium ion battery cells.

At this time, cost appears to be a serious hinderance for the introduction of lithium ion battery packs. Rumor has GM considering "leasing" the lithium ion battery pack for the upcoming Volt vehicle.

 

FASLE FALSE FALSE!

Only very specific ( low budget ) lap-top or consumer "toy" grade batteries had a tendency to do that. And that was due ( in large part ) to the multiple cells not being balanced correctly ( or at all )... something that is monitored very closely in the PHEV battery packs.

Another large part is the chemistry inside has actually changed also.
-John

 

Yes, real industry grade Lithium-Ion cells have numerous circuit breaker and safety valve and cutoff features that prevent any kind of thermal runaway.

Price is a big problem as are standards right now, but once they're solved we'll see a big revolution in transporation technology.

As to the Plug-In, it gets fantastic mileage by being an electric car for a range (which varies, obviously depending on the pack, from 10-80 miles I've seen the last few days at NAIAS), which once depleted, then runs as a standard HEV vehicle, at which point, it will then get the "piddley" 30-40 MPGs that the rest of us do, but with that extra 80 miles at infinite MPG, end up averaging over 150 MPG over the course of a long drive; which can cause weird MPG numbers for testing. If you have a PHEV 30 (That's 30 miles of all electric range), and a 20 mile commute, you may go months on end without ever using more than a teacup worths of fuel. On the other hand, if you're driving across the country, you're going to use a lot of fuel if you don't recharge often.

 

So what is the likelihood that the current crop of FEHs can be retrofited for a reasonable cost in the future to a high mileage version

 

To clarify, certain chemistries of lithium ion batteries do have potential to explode/ignite. It's sort of a "meltdown", where chemical reactions accelerate due to increased temperature, causing further heating and more reactions and so on. That's what PP was talking about when he mentioned "thermal runaway". The Tesla electric car uses powerful lithium batteries but incorporates safety features to prevent problems. Another alternative is to choose a battery design that is not prone to the problem in the first place, but that can be a trade-off.

Arrangements in a motor vehicle have already been created that appear safe and reliable. And the number one concern for cars is safety. One single incident, be it a meltdown or an actual fire, has the potential to ruin a vehicle's reputation permanently.

Lithium ion is seen as the best alternative today since vehicles require a battery that is small/light yet powerful, and lithium ion batteries are about half the weight and produce about twice the power of batteries like the one in your FEH. But a system like the one in the PHEVs that Ford's testing now is very expensive. Ford says there would need to be incentives (i.e. tax credits) to drive demand.

They have also confirmed that they've been testing different versions and have some good results, but they are not going to act until a supplier steps up with a battery that meets the design requirements.

 

I was wondering the same thing...what happens if an aftermarket company just adds on more battery to what we have now? Would the computer "know" there was an additional battery or just use the pair the same as the OEM and we would just have more capacity?

 

One of the differences, is that with our hybrids, the ICE needs to be started, warmed up, and kept warmed up while driving.

With a plug-in hybrid, the ICE is not required to be started when you first turn the key. The ICE is kept off, and therefore kept cold, until it is finally needed. Then, and only then, is it started, warmed up, and kept warmed up.

Also, I assume with a plug-in, one would want an EV mode that can go faster than around 25-39 MPH. Possibly, that is a different electric motor, or a different eCVT (different or varying ratios for the electric motor)?