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This is the title of an article in Engineering & Technology (E&T) magazine Vol 3 Issue 2 9-22 Feb. 2008, accessible only to members.
It describes how the author added an extra Li-ion battery to obtain a claimed 100 mpg plus. However, because the battery characteristics do not match those of the original NiMH, he used the power from the Li-ion only to charge the NiMH when it was running low. The power to charge the Li-ion came from the power grid, not from the engine.
This is a cheat, pure and simple, by making the car a plug-in, because he counts only the energy he uses in the fuel to get his 100 mpg, ignoring the fuel burnt in the power station. This is like saying that an electric vehicle gets a fuel consumption of 0 l/100 km or infinity mpg. His battery required about 12 kWh to charge, requiring typically about 40 kWh of fuel at the power station. This is equivalent to about 4 litres of petrol (gasoline). The author doesn't say what his actual performance improvement is, in real figures. However, he does say the NiMH would take the car one mile at 31 mph, with a capacity of 1 Ah. The battery he used was 50 Ah at 200 V, which he had to step up to 240 V, giving an effective 40 Ah at 95% converter efficiency, so he could get an extra 40 miles per charge or roughly 40 mpg, which is worse than using the Prius normally. Assuming the power station was powered with fossil fuels, there would be a net loss in terms of emissions (and pollution).
So, what would be gained? Because UK petrol is heavily taxed and electricity isn't, he would gain a mite in running costs, but anyone whose family can run two Prius cars and can afford the cost of hyper-expensive Li-ion batteries, cannot be short of money, bearing in mind that such batteries have a short lifetime (whether they are used or not). I suggest that all he can gain is the satisfaction of seeing 99.9 mpg on his display on relatively short runs, while defeating the purpose of buying a Prius in the first place.
In other words, his 100 mpg smells of male bovine excrement.
It describes how the author added an extra Li-ion battery to obtain a claimed 100 mpg plus. However, because the battery characteristics do not match those of the original NiMH, he used the power from the Li-ion only to charge the NiMH when it was running low. The power to charge the Li-ion came from the power grid, not from the engine.
This is a cheat, pure and simple, by making the car a plug-in, because he counts only the energy he uses in the fuel to get his 100 mpg, ignoring the fuel burnt in the power station. This is like saying that an electric vehicle gets a fuel consumption of 0 l/100 km or infinity mpg. His battery required about 12 kWh to charge, requiring typically about 40 kWh of fuel at the power station. This is equivalent to about 4 litres of petrol (gasoline). The author doesn't say what his actual performance improvement is, in real figures. However, he does say the NiMH would take the car one mile at 31 mph, with a capacity of 1 Ah. The battery he used was 50 Ah at 200 V, which he had to step up to 240 V, giving an effective 40 Ah at 95% converter efficiency, so he could get an extra 40 miles per charge or roughly 40 mpg, which is worse than using the Prius normally. Assuming the power station was powered with fossil fuels, there would be a net loss in terms of emissions (and pollution).
So, what would be gained? Because UK petrol is heavily taxed and electricity isn't, he would gain a mite in running costs, but anyone whose family can run two Prius cars and can afford the cost of hyper-expensive Li-ion batteries, cannot be short of money, bearing in mind that such batteries have a short lifetime (whether they are used or not). I suggest that all he can gain is the satisfaction of seeing 99.9 mpg on his display on relatively short runs, while defeating the purpose of buying a Prius in the first place.
In other words, his 100 mpg smells of male bovine excrement.
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