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Super-fast EVCPs?

Chris Pearson
I don't think that I have seen this in here before, but these batteries came up in a motoring forum.


The claim to charge an EV all the way in 5 min seems to be entirely spurious - all that they have managed so far is a moped, but even if the batteries existed, how would they be charged?


Here is my back-of-a-fag-packet calculation. An average EV will do 4 - 5 miles per kWh; let's be conservative and say 4. So with a range of 300 miles between charges, that requires 75 kWh. Delivered over 1/12 hour that requires 900 kW. So in round terms, that is one 1 MVA transformer per EVCP. Could be useful on a motorway, but I cannot see the point elsewhere. Even then, very few journeys in UK are over 300 miles. Both Edinburgh and Land's End are closer to Birmingham than that.


900 kW at 48 V DC is almost 20,000 amps. What sort of connexion is envisaged?
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    This is not practical at all, because a suitable connector and cables for 1MVA would not be able to be lifted by the average member of the public. The chemical reaction needed to store this energy is also extremely dangerous, it would need a 1MVA electronic converter as charge controller with an efficiency of 95% if you are lucky, so a way of dissipating 50 kW. This is going to be a hot little filling station. The capital cost would also be very high, much more than a few tanks and pipes.  Ah, I know various people are trying contactless charging you say, but at this power level that is going to be even more expensive. Charging the battery is going to make it also have a great deal of heat to dissipate somehow, probably 100kW, so you again have a huge heat problem, which electric vehicles already have during discharge but at a much lower level.


    The biggest snag is that we don't have the electricity, of course, so add the cost of a few nuclear power stations to the bill and electric cars are simply not an economic proposition, and presently receive a ridiculous level of subsidy from the rest of us, the magnitude of which has yet to be appreciated. Germany is trying renewables quite hard and now has the most expensive electricity in the World, they are deciding to build more coal-powered stations as a backup to the unreliables. One cannot make it up.
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    This is not practical at all, because a suitable connector and cables for 1MVA would not be able to be lifted by the average member of the public. The chemical reaction needed to store this energy is also extremely dangerous, it would need a 1MVA electronic converter as charge controller with an efficiency of 95% if you are lucky, so a way of dissipating 50 kW. This is going to be a hot little filling station. The capital cost would also be very high, much more than a few tanks and pipes.  Ah, I know various people are trying contactless charging you say, but at this power level that is going to be even more expensive. Charging the battery is going to make it also have a great deal of heat to dissipate somehow, probably 100kW, so you again have a huge heat problem, which electric vehicles already have during discharge but at a much lower level.


    The biggest snag is that we don't have the electricity, of course, so add the cost of a few nuclear power stations to the bill and electric cars are simply not an economic proposition, and presently receive a ridiculous level of subsidy from the rest of us, the magnitude of which has yet to be appreciated. Germany is trying renewables quite hard and now has the most expensive electricity in the World, they are deciding to build more coal-powered stations as a backup to the unreliables. One cannot make it up.
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