Friday, June 21, 2013

Tesla Messla Announces the 90 Second Battery Swap

The Musketeer dressed as a circus announcer held stage this week to launch his 90 second battery swap idea.  The crowd went wild watching the two ring circus of a guy filling up his normal car with gasoline side by side with the rapid swap of the 85 kwh battery pack on a Model S.  Of course the Model S swap was faster as the guy with gasoline filled up with just over 23.2 gallons of gas and had to pay for the transaction with a credit card while the Model S guy just sat in his car watching the 19 inch screen show he was now tanked up.  Here is the video if you are interested to be entertained by a clown dressed in a tuxedo jacket.

Now let’s analyze the thermodynamics and economics of the side by side transactions.

The 23.22 gallons with the DOE energy content of 37.3 kwh per gallon meant 866.1 kwh of energy was transferred from the gas pump to the car in essentially the same time the Teslacle got a measly 85 kwh of energy transferred.  Actually less than 85 kwh as the old battery in the Teslacle probably had some charge left.  A ten times larger transfer of energy in the same amount of time in the case of the gasoline car.  Thermodynamics round 101 to the gasoline Audi by a ten to one margin.

The 23.22 gallons cost the gasoline car owner $99.83 for the fill-up.  The battery swap for the 85 kwh of batteries at a real price of $1,000 per kwh was a transaction that was valued at $85,000.  Granted Elon got back an uncharged battery pack and it has value so let’s now assume old Elon has to keep 1.5 packs for each car as he is offering the 90 second swap he needs extra packs.  Let’s round out value of the 1.5 packs to $120,000 and let’s assume the 1.5 packs will propel vehicles a total of 120,000 miles.  This is a cost of $1 per mile.    Even if the Musketeer gives away the electrons for free and the Audi only gets 22 MPG the Teslacle owner or someone will pay the equivalent of $22 per gallon.  This is five times as much as Audi owner paid for premium gas. Economics round 101 to the gasoline Audi by a five to one margin.

Now for the zinger the Audi will go 510 miles on the 23.22 gallons of premium grade gasoline.  The Teslacle will barely do 230 miles.  So the Teslacle owner will waste his time on 2.22 battery swaps for each time the Audi owner wastes his precious time at the pump.  The Audi owner saves time as it is not a case of one battery swap for one gas fill up but 2.22 battery swaps for each gas fill-up.  Time Management round 101 to the Gasoline Audi by a 2.22 to one margin.

The Audi wins by 10 times 5 times 2.2 or 110 fold over the Teslacle.  The Musketeer could have made it a three ring circus if he had his Solar City PV cells on the dark stage and claimed that these new cells even make electricity when it is pitch black outside simply from the vibrational sound of circus music.  Now that would have been something for the thermodynamic neophytes in the audience to applaud.

Old Monty had a Flying Circus and Elon is just not quite levitating yet.  That will be next when he brings SpaceX into the act of flying Model Ss that are refilled in mid-flight.


  1. The energy in the Audi's gasoline of 866 kWh has to be reduced by about 75% due to the inefficiency of an internal combustion engine, so maybe 220 kWh are not wasted in heating the environment. The 85 kWh (or whatever it is) in the Tesla's batter will be over 90% efficient. So, take your 10:1 and reduce by a factor of 75%. The comparable ratio is actually 2.5:1 or 3:1, not 10:1. Certainly not insignificant but still, you're claiming misleading numbers from others, you need to be scrupulous in your own accuracy.

  2. My earlier comment was after a very quick scan. But after watching the video and reading more carefully it's clear that this entire post is nonsense. Forget the foolishness about $1/mile. The point is that it gives a Tesla owner a choice of a quick recharge on his or her way from Los Angeles to Las Vegas or whatever. In that specific situation, yes the Audi wins.

    But that's entirely irrelevant and a total straw man argument becasue: 1) Most of the time, the Tesla owner will spend no time at a charging station or battery pack exchange, he or she will drive to his or her destination and charge there while transacting whatever business constituted the purpose of the trip or will drive to the destination(s), drive home, plug in the car and go in and do whatever is to be done at home. Were I in a Tesla S (which I'm not), it would be very rare indeed that I'd stop at a Tesla charging station to either charge the pack in my car or change it out. My commute is 62 miles and I drive to client locations, project sites, etc. on a regular basis. I average around 22,000 miles per year. Perhaps once or twice in the last year did I exceed the range of a Tesla in a day. On those days, I'd have had the choice mentioned in the video. But nearly all of my miles would have been driven with zero stops of any kind and nearly all of them would have been at a rate of something like $0.05 (assuming $0.15/kilowatt hour, my premium rate, and .33 kWh/mile). The Lexus CT200h hybrid I actually drive costs about $0.06/mile in gasoline (I hypermile at a bit over 50 m.p.g. over its lifetime of three years and four months and assume $3.00/gallon). And, at the most recent scheduled service I spent $1,300 on items most of which wouldn't be done in a Tesla. And I really like my CT200h.

    Further, clearly the Tesla is an expensive car. People know that when they buy it. Presumably, they buy the car, install a charger, etc. They do this because they want the features that the car has, just as they buyer of a Porsche or any other premium priced car does. But your analysis is just plain silly.

    I was going to go through point by point and address your multipliers, but I realized there is no reason to do so. The entire content of the post is addressing a non-existent situation.