More GM Volt Spin

"The ONLY hurdle in getting a good series-hybrid to market is the battery, and GM are ahead of Toyota on this at the moment because of the exclusive non-compete agreements they have with so many LiIon manufacturers. (The existing NiMH in the Prius is not suitable for series hybrid use.)"

How do you explain darelldd's 14-year-old NiMH ALL-ELECTRIC Rav4? Not suitable for electric cars? Seems there is room for NiMH...tried and tested and proven and cheap(er) than Li (right now)...what more do you want?

Yes, Li is better suited for cars than NiMH (better energy output, less weight/mass) and the next successor to NiMH...but to say NiMH is not viable for an electric car...what am I missing here?

Darelldd are you putting us all on by claiming your Rav4 is all that...without Li?

 

<div class='quotetop'>QUOTE(efusco @ Aug 23 2007, 09:46 AM) [snapback]501048[/snapback]</div>

I agree. This is the car that I want. 40 miles without charging, plug in at night, ICE for extended range.

I'm not holding my breath for this car, nor will I be an early adopter. When it is car is made and has a few years under its belt, it will become my daily driver.

 

<div class='quotetop'>QUOTE(efusco @ Aug 23 2007, 11:38 AM) [snapback]500999[/snapback]</div>

So the rain barrel collects the rain and it feeds in to a little water/windmill that is assisted by wind. The windmill turns so that it recharges the battery or turns the electric motor which in turn charges the battery? :lol:

 

I think there's no way GM won't come out with the Volt now. They've hyped it too much and committed too much to its development.

Maybe they won't hit some of the targets on range, production, price, etc., but I really do feel that the Volt is coming and that it's going to be a great car (for a GM).

 

<div class='quotetop'>QUOTE(hobbit @ Aug 23 2007, 08:35 AM) [snapback]500995[/snapback]</div>

Can you provide a flowchart or other diagram for this process? :lol:

 

<div class='quotetop'>QUOTE(Boulder Bum @ Aug 23 2007, 01:47 PM) [snapback]501091[/snapback]</div>

Maybe GM will be able to license the technology in the current Prius once Toyota goes to the next generation. This is the only way I can see for them to be able to make a reliable hybrid that people will buy.

Chevy dealer: Can't get a Prius? Well we have the Volt, which is a rebadged Prius that now has a $5000 rebate so it's only $25000 if you buy it today.

 

I'm now predicting in a couple of years, some GM marketing person will answer a question like this:

"Volt? What's a Volt? We never said anything about an electric car!"

Assuming GM isn't bought by some other company (I predict Kia) by then.

 

<div class='quotetop'>QUOTE(finman @ Aug 23 2007, 01:24 PM) [snapback]501068[/snapback]</div>

NiMH works OK in large format for BEVs, but there are three main problems with using NiMH for a series-hybrid.

The first is that you always have to balance cycle life with power density with NiMH batteries. The Prius battery is small, and designed for many very shallow, fast cycles. The RAV4 EV battery pack is different, it can cope with many deep, slow cycles because it is absolutely huge (it weighs over 1000 lbs), and so the current drawn from each cell or module is very gentle indeed. Essentially the pack is being babied throughout its life because it is so big. You couldn't do this with a small 8 kWh series-hybrid pack and still get 70-100 kW out with NiMH.

The next issue is that of input/output efficiency. If you are using an engine to charge the batteries, then using that stored energy to power the vehicle, a series-hybrid can only be competitive (in this driving mode) with an ordinary transmission if the efficiency of the battery storage is high. This is no problem with lithium-ion (>95% out for what you put in), but NiMH in this size would be more like 60-70% - and you can't afford to waste 30-40% of the engine's output energy like that (which is why the Prius uses the series/parallel trick to keep a connection from engine to wheels to avoid the NiMH losses).

Finally, there is the Cobasys legal / patent issue, whereby you can only use NiMH in sizes up to about 2 kWh (?) in the American market. Above that, you have to pay out lots of royalties, so NiMH for a series-hybrid is no go for that reason too. Toyota has already payed out megabucks in legal disputes to Cobasys over NiMH, so they are very keen to move on to lithium.

 

<div class='quotetop'>QUOTE(Stev0 @ Aug 23 2007, 11:46 PM) [snapback]501380[/snapback]</div>

By then GM will be touting their new hydrogen hybrid that's going to really advance them past Toyota. You see, even if GM comes out with the Volt, Toyota will have their next version out and Gm will be trying to PR their way into being competitive with their next illusion. GM doesnn't want any of this to happen period.

 

Thanks, clett! I knew you'd have a realistic, fact-based reply. Makes sense now. Appreciate it.

So, with that Cobasys patent...is the Rav4 EV violating that right now? Were the other large-scale NiMH electric cars?

Curious how all this works AGAINST the common good of humanity...yet works for the FEW who stand to get rich.