There was a post like this before. You have to go back to March of 2011 to find it.
The Nissan Leaf is used as a benchmark in order to calculate the range based upon a number of driving conditions. From those numbers, one can speculate a bit about the capacity of batteries and fuel cell combos, which is what I did back then. From these numbers, you can estimate what kind of capacity of fuel cell you would need for a given size battery with the range according to this chart.
The chart is presented below.
For example, long distance driving, assume 55 mph highway speed, 95 degree temperature, and air conditioner on. From this one can derive the discharge rate--in kilowatts per hour--- which is to the left of each driving condition. As you can see, the greatest discharge rate occurs at 20 kilowatts per hour at highway speed, 95 degrees Farenheit, and air conditioner on.
Let's go back to the Mars car that Aronsson claims has a 200 mile range. Using this chart as a basis, one can estimate the capabilities of his propulsion system in terms of kilowatt-hours.
Lets assume 20 kw drain hwy-if he uses only one 5 kwh fuel cell, then this means 15 kwh drain hwy, if 30 kwh battery,then 2 hours drive range-about 110 miles or so. Not far enough range. You'd have to bump the battery up to 45 kilowatt-hours to get a sufficient range. That's nearly twice the capacity of the Leaf's 24 kilowatt-hour batteries.
Are his batteries that good?
What about the Silver Volt? He says 146 mile range on those batteries. Divide 146 by 55 and you get 2.65 hours. At 20 kilowatt drain, that would imply a little over 50 kilowatt hour battery pack. This is what I was assuming before. Now, a car that big may be able to house that much of a battery pack. A battery pack of that size would weigh a whole lot. Would that little Mars car be capable of housing nearly 45 kilowatt-hours worth of batteries?
A key point to observe--- differing conditions give different ranges. The Leaf's range varied from 47 miles to 138 miles, depending upon conditions. When a range is claimed, it has to be qualified based upon what the conditions. If it is ideal conditions, such as with the Leaf, the quoted capacity of the battery may be much less than I'm calculating here.
Therefore, Aronsson's claims are unqualified, giving reason for skepticism. You may assume highway driving, but if it were highway driving, then that is the least ideal driving condition, and therefore the capacity of the battery must be at the highest rating. If Aronsson's claims are assuming ideal conditions, then his battery would not have much more capacity than the Leaf's. The Leaf has a 24 kilowatt-hour battery pack.
Aronsson's claims have to be fully tested as with the Leaf here. Otherwise, his claims don't mean much.
He did say on his videos that he took his cars on the highway to Washington DC and then to Los Angeles shortly after Obama became President. But I haven't found any record of that event on the web.
Does anybody know of this?
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| Using chart derived from post of March 24, 2011 and wikipedia |
Update:
This will not be the last of these posts. More to come. By the way, if this post seems negative, please do not misunderstand. If anything, I am totally incredulous that this technology hasn't taken over the freaking world. One has to assume that there is something wrong with this technology for an explanation for its non-adoption. But what if that isn't the case? What if this is the real deal? The mind staggers at this proposition.
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