Dave Goldstein wrote: > > There was never any doubt that you intended to go > with Nickel Zinc (NiZn) which, for a variety of reasons, > has not been a serious battery contender with the US > Advanced Battery Consortium (USABC) for many years.
Do you know Dave what exactly these reasons are? Evercel just emerged with EV-capable battery this year, so USABC should re-evaluate it. Not saying that the results are going to be acceptable, just USABC may not keep up with rapid developments. Evercell might be just as good but yet to prove it. Ovonic already did. (Availability/price is other topic). > > >2.) Battery Weight: If you wanted to use the > > > 85 ah EV1 NiMH batteries, this would > > > effectively limit you to 250 volts (19 > modules @ 13.2 > > volts, @18 kg = 750 lbs > > > 19.3 kWh of battery. In a > > > 2,350 lb car with good aero, that should > > > deliver better than 100 miles of range! > > > > Again, diss the NiMH idea, and go with simple and so far as > > demonstrated in Sheer's car, very strong Nickel Zinc batteries. > > Wrong conclusion, John! Neither the large EV1 NiMH > > > >** Note to Victor: Would 250 volts be > > > sufficient for your 1PV5105WS12 AC motor system? > > > > Victor says yes, but worries over a lower efficiency level...I do > > not, but I'll go into this later. > > Victor indicated a strong preference for 300+ volts to > do the job properly. There is no doubt that you can > build a lower voltage, lower efficiency AC system, as > I think Victor would agree, but why would you WANT to? 1. Once I have acceptable NiMH model, I can simply simulate performance at any voltage level. This will shed some light to this debate. To do this I need following: Internal resistance of NiMH in question vs SOC plot ot table Discharge curves for different rates. Does any of you know where to get this info? 2. I was referring to Siemens AC system, but this is not the only system out there. As Dave mentioned, Brusa makes quality systems as well. Air cooled and less powerful than Siemens, but nevertheless it's an alternative to some people. > > > 3.) Volume: This is really tricky. 19 EV1 NiMH's would > > > occupy ~ 5 cubic feet! That's 141 liters or approx. the > > > size of a 37 gallon (U.S.) tank! Could this *possibly* be > > > shoehorned into an Insight?! Frankly, I doubt it. > > Again.....diss the NiMH idea, and go with simple and so far as > > demonstrated in Sheer's car, very strong Nickel Zinc batteries. > wrong! > > Chill, John! No one, least of all me, is challenging you on > your knowledge of the car. This is simply about *how many* > > You're not taking into account, the way NiMH batteries > > have to be kept in their sweet spot, > > ALL batteries lose power as the capacity drops. > > > > And the expected battery life of NiZn in a heavy- > > > duty EV application is still an open question. > > > > On this, we agree. But....so far as we're seeing out west here > > with Sheer's car, the batteries do everything the company touts ... > > I think that could be a mistake. But so long as you are > willing to spend the money to find out, I encourage you to > go with this. > > There is more than one way to build an EV and every > approach requires certain compromises to be made. > So long as you have defined what is most important > to you and what compromises you are willing to accept, > then no one can say that you are wrong. > > Beyond that, I am not going to waste any more > bandwith arguing design philosophies. I will be > on travel for the next 10 days, and will be unable > to respond to additional comments until I return. > > Good luck! > > Regards, > > Dave Goldstein > President, EVA/DC and > Program Development Associates > Gaithersburg, MD > I must admit that with all respect to John, he for his unexplainable reasons sometimes sticks to an ideas that are so wrong that it's painfully obvious to anyone else. If asked for reasons, he's saying "I just happen to disagree, on this one" without further facts. Not saying discussed topic is one of them. Authority dominates, and many people take opinions and advises for granted without second thought or considering different set of priorities. Some people just feel uncomfortable to challenge the experts. Sure, listen to experts, and John is one of them. Very experienced one, but still an human being with own set of values, priorities, and depth of pocket book influencing decisions. My advise is - take information from anyone as a food for thought, home work research and consideration, not direct instructions how to do things. Facts are facts (like which battery has more energy density) but opinions are just opinions (like should I use NiZn in *my* insight so with the way *I* drive I can go *this* far and *this* fast, which meets *my* needs/budget/priorities/wishes/fun factor/). BTW, lacking of proper mathematical model of NiZn I used PbA (Optima) characteristics and just halved Optima's weight to make crude representation of NiZn for the max performance simulation. You cannot do range simulation this way, and the voltage drop at max acceleration is likely different too. Nevertheless, 288V nom pack with Siemens inverter and 1PV5105WS12 small motor will provide Insight with 0-60 in 12 sec, max speed above 200 km/h (>125 MPH), needs 12 kW to move 100 km/h and spends 120 Wh/km *at that speed*. On the second gear at 7000 RPM it moves 130 km/h (81 MPH). On the third at 125 MPH it makes just 6600 RPM. The total weight (with driver) for simulation was 1,315 kg. Good enough? You decide for your needs. See: http://www.metricmind.com/misc/5105_24x1_1315kg_speed.jpg http://www.metricmind.com/misc/5105_24x1_1315kg_energy.jpg http://www.metricmind.com/misc/5105_24x1_1315kg_current.jpg http://www.metricmind.com/misc/5105_24x1_1315kg_economy.jpg Victor
