Charging system

Charging system

Hi all. I'm new to this forum so this may be a topic already covered and if so, I apologize.
It's a given, as far as I'm concerned, that these Tesla automobiles are far ahead of the electric car game. However, I have a small point to make in regard to charging one of these awesome machines; with such advanced electronic and mechanical technology displayed here, why is there not an on-board charging system applied to these vehicles? Could the existing grill area not have a working purpose such as an air dam to supply a concentrated flow of air for a fan that would turn a shaft in a ratio reduced gear box that would in turn, spin a generator that produces regulated voltage to charge the batteries and keep them charged. The mileage of the vehicle would be unlimited. Is this too simple?

cloroxbb | May 25, 2013

Ughhh how many times are people going to start a thread with their "perpetual motion" ideas.

Sorry man, but it takes energy to make energy, and you get loss.

Putting in a turbine will increase drag, which in turn DECREASES range more than it produces.

The ONLY energy returning idea that makes sense is regenerative braking, and the Teslas already do that.

Physics is what disallows what you are proposing.

Brian H | May 25, 2013

Yes, "simple" and wrong.

This is another in a long line of perpetual motion schemes people keep bringing up here. The "air flow" you want to exploit is created by the car's motion in the first place, which was created by the car's stored energy. You increase drag and recover less than the motion cost in energy trying to use "windmill" fans attached to the car. Fundamentally the same as regenerative braking, which is used to slow the car deliberately by increasing drag and recovering electrical energy by spinning the motor as a generator using the car's momentum -- always with losses; you never get back as much as you put in.

carlgo | May 25, 2013

Better yet, use pneumatic power. Tesla bumpers would actually be air bags. Tesla drivers would access each other via the tablet interface and arrange to bump each other as they drive down the highway. The air would be forced through hoses into bi-directinal turbines which would then generate electricity to charge the batteries, both on compression and decompression.

Oblong tires could do the same thing. The air would be compressed each time a high end hit the road and then air would rush back when the tire was momentarily airborne. This would result in four air pulses per revolution, per tire.

Skeptics will of course say that the impact forces would be in effect drag and so these ideas would not work. Bumping the car ahead of you would slow you down, but that by taking turns bumping and being bumped would even things out.

In the case of the oblong tires, don't forget that the tires are airborne half the time. The savings in drag and friction will even this out.

J.T. | May 25, 2013

It's easier than all that. Simply use the current in the battery to form an electromagnet and have 1/2 the cars built with north front ends and 1/2 built with south front ends. Add a color coded lens to the rear hatch to denote the pole and we can all just push each other along. The cars in the sandwich could effectively coast.

I think that will work because i'm pretty sure it works with paper clips.

carlgo | May 26, 2013

I bow to the more elegant solution. The answers are right in front of us in those desktop executive toys.

Your plan, however, requires that the right ratio of pushers and pullers to show up, and randy people might try to hook up with cars of the wrong polarity and that could cause big problems. You can duplicate them by playing with magnets on your desk when the boss is away.

Imagine driving down the road, minding your own business, when suddenly some fool with a positive front bumper comes up on your negative rear bumper! That car would stick to yours and you would literally be stuck with it, and a potentially creepy driver, for who knows how long.

How about a variation of your idea, using simple electrical contacts front and rear. This would enable all Teslas to hook up. Imagine three or 17 or 60 Testlas nose to tail, alternating the use of their power and sharing it via contacts in the front and rear bumpers. Cruising along at 75, all drafting each other, probably only requires the power of at most one in four cars. Clever software would alternate power of each car, say every few minutes my car would power four cars, then yours would kick in and so on. Kind of like cutting out cylinders in a gas car when all of them are not needed.

This should extend cruising distance by at least 4x.

Surely the Highway Patrol would be supportive as it would ease congestion.

J.T. | May 26, 2013

It would also be popular for funeral processions.

Brian H | May 26, 2013

I used to play that game on my VIC-20. I think it was called Caterpillar.

Timo | May 27, 2013

Attach a harpoon gun in front of the vehicle, shoot at the nearest truck going at right direction, get a zero charge trip.

...what? This is just as meaningful idea than any of the above.

rmitchum | May 27, 2013

@ Timo
Are you forgetting about regen?
= POSITIVE charge trip! :-)

Tiebreaker | May 27, 2013

Tesla themselves had solved this, a couple of years ago: they are selling a cable that goes from the cigarette lighter to the charging port, charging the battery while driving. Darn it. I can't find the item any longer... I wonder why?

carlgo | May 27, 2013

Recalled because the wire gauge was too thin and got hot.

wcalvin | May 27, 2013

Depends on air resistance. Letting some of the compressed air wave up front flow escape through a fan-generator in the grill will help recharge a little (though not "mileage unlimited." But try scaling this up to the point you add air resistance--then the no-free-lunch arguments apply.

EDH AL | May 27, 2013

@ AI2112

After reading all these "helpful" responses I can feel your pain. Don't take it personal; its just the way exuberant Tesla fans like to welcome New Fans -- mercilessly!

Timo | May 27, 2013

@wcalvin, fan doesn't help there, if you can drop air resistance, then do it without the fan, you get more out of it.

olanmills | May 28, 2013

you guys are cracking me up

Bumper car generators! I would love to see an animated illustration. I can imagine the late night infomercial for the Tesla free energy bumper cars, only 49 payments 1,995.00

Brian H | May 28, 2013

Going faster by increasing air resistance is not on. No matter what.

wcalvin | May 28, 2013

Agree with Timo: Optimal escape paths for the bow wave would leave no opportunity for a fan generator to trickle charge.

olanmills | May 29, 2013

wcalvin, you're thinking too hard about it. The only reason a wave of air is created is because the car is moving. Turning a fan is even more difficult than forcing the air around the vehicle. Turning a fan that is connected to a dynamo is even harder. Adding a fan will decrease efficiency. Adding a fan and a dynamo will decrease efficiency even more. The air flow isn't free energy because the airflow is created by the motion of the car, and the motion of the car is created by the electricity from the battery.

TSLAholic | September 22, 2013

A couple of ideas here...
Has anyone considered the fact that there is a huge potential for additional charging available that no Tesla owner has taken advantage of yet? This is the only solution that does not propose to break any laws of physics! How many times have Tesla owners given away free information about the car and company to complete strangers? Stock tips and tco advantages, as a result of which, all the curious people either invest in the company or buy the car and are therefore financially rewarded. The solution is simple, once a small crowd of people with questions has gathered around the car, put them to work! Have them push the car around the parking lot for as long as they ask questions and get answers, while regen does its thing. No laws of physics are broken (aside from a few labor laws maybe) but I really don't see that being a problem until and if the pushers begin to unionize.
Second idea involves those instances when no one is around to push the car (or once everyone is aware of Tesla, and the constant gatherings around the Model S have stopped, therefore depleting the perpetual regen potential)
Remember when you were younger and complained about something being difficult just to hear your elders proclaim that when they were young, they had to walk to school/work uphill both ways? All you have to do is find that hill and use it to drive in the opposite direction they used to walk in. So you're always driving downhill and the battery is always topped off. Simple!

Timo | September 22, 2013

@Walter Harold Marlin;

Air compressor & alternator combo has worse energy density than batteries. Way worse. No point making such thing. Using on-board gas generator for compressing air is even worse than using external generator.

Timo | September 23, 2013

Eh? Another perpetual machine advocate? Just FYI, that doesn't work.

TSLAholic | September 23, 2013

Man, and I thought I was the only one who was busy pulling girls' pigtails instead of paying attention during physics classes!

Nodding_Dog | September 23, 2013

Hi all. I'm a newbie to this site but a big fan of Tesla Motors. On the subject of charging systems, why is there no solar top-up facility on the vehicles? Now I know that current solar technology is way too inefficient, but there's a company here in Australia called Dyesol, which has already developed an "artificial photosynthesis", using dye technology, incorporated into the paintwork on colorbonded steel and also glass. So the entire surface of the car becomes a solar panel. It has proven to give vast amounts more energy per square cm than conventional solar cells. The glass roof of the Model S could easily charge the batteries while being driven or simply sitting parked in the sun. Any light source in fact. Doesn't need to be full sun.

As to the batteries, the company "M-Phase technologies" has developed Nano-battery technology with power on demand. The power is produced only when a signal is sent to the battery. This is not future technology. They have products on the market right now.
Imagine the Model S with a range of 3000 km per charge instead of 500 km.
Elon, I suggest you Google both companies and have a look.

Brian H | September 23, 2013

Walter the Dim;
All the energy stored by the first fill-up gets used in moving the car. There is no extra. There are numerous losses. Turning an alternator will reduce range, and return less than is used to crank it. Now go away.

TSLAholic | September 23, 2013

"Simple. My first post on the Sept. 22 was to get someone at Tesla 'Motors' attention."

Mission status: Fail.

We should seriously number each and every thread of such nature. This would at least get people to visualize how many have come before them with their very own, special, breakthrough idea for perpetual motion.
We could keep a list of links of these threads and to save ourselves the headache, replies to such threads would consist of nothing more than the list of links to previous threads.
Wait for it.... Simple!

Timo | September 23, 2013

@Walter Harold Marlin;

Alternators are not magical devices that make electricity out of nowhere. You need energy.

Where do you get the energy to fill that air tank? Visualize.

Timo | September 24, 2013

So, where does the energy to fill up the air tank come from?

bent | September 24, 2013

There exists a general perception that electricity in a conventional ICE car is free. There is some basis to this idea since unless you're driving in the Mojave or in arctic winter the cost of the electricity used in a car is essentially a rounding error when compared to the cost of the gas used to propel the car forwards.

So it's not completely unreasonable to consider that the electricity has zero cost. This zero cost electricity is, as any idiot knows (apparently), created by the alternator. This makes the alternator a magical source of zero cost energy.

This, I believe, is the basic source of all this perpetual motion alternator crackpottery that we get. The primary disconnect is that in an EV, the electricity that is used – overall – is not free at all since it is the sole source of the energy needed to propel the car. The "electricity is effectively free within a rounding error" approximation therefore no longer holds and you need to start considering the electricity to have an actual cost (much) bigger than zero. This suddenly makes the alternator non-magical and boring.

In an EV you could still hold that the electricity needed to run the car's appliances (i.e. everything but forwards motion and battery temperature management) is approximately free. This would make the on-board DC/DC converter the EV's magical source of zero cost energy.

I should get one of those perpetual motion DC/DC converters to run my home off of. I'll never need to pay an electricity bill ever again!

Timo | September 24, 2013

Doesn't work like that. Where does the energy to fill up the air tank come from? It's a simple question, just answer that.

Brian H | September 24, 2013

Vanish, fool.

Timo | September 24, 2013

Don't drive him away, it's fun to see how long it takes for him to understand what is wrong in his suggestion. I know he can't answer my question, but how long it takes for him to realize that is the question.

Timo | September 24, 2013

Answer the question. Where does the energy come from to fill up the air tank? It's a simple question.

Objective1 | September 25, 2013

Walter, I think you are saying some air turbine, driven by the air moving past the moving car, will pump up the compressed air tanks.

But that air turbine increases the wind resistance of the car, requiring more energy from the battery to keep the car moving. All the energy to fill the air tank is still coming from the battery of the car in the end. And without perfect efficiency, you lose more energy than you gain this way.

That's the problem.

TSLAholic | September 25, 2013

There seems to be no way for us to comprehend what you are trying to explain. Our little type 0 society brains are simply not yet aware of how to properly harness the energy we so eagerly desire.
Won't you kindly take a little bit of your personal time to assemble and demo a simple proof of concept model for us? Please be sure to show your energy conversion calculations after the initial fill of the air tank.

Timo | September 25, 2013

So perpetual machine: it fills itself. Walter has no clue about physics which was pretty much what I expected. No need to tease him any further.

holidayday | September 26, 2013

Walter: "It is self-sustaining."

No. It. is. not.

You cannot empty the air tank to gain energy to move the car, and then have the tank filled again for free.

Energy is needed to refill the tank. If you fill the tank from batteries, you are just using the same energy that would be used to move the car.
The "on board air power air compressor" need to get energy from somewhere, and the only place that is "on board" is the battery.

The only extra energy that can be used is the first time you fill the tank. Any refilling of the tank would need to be external, or else you would just be using the battery to fill it up.

And the quick solution? Make a bigger battery so you don't have to have extra energy to keep refilling an air tank that would just recharge the battery. (Which Tesla has already done!)

Blueshift | September 26, 2013

(sarcasm on)

We should use this in electric power plants:

Giant air tank discharges to spin turbin generating electricity for 300,000 homes. That same electricty is used to run a compressor which re-fills the air tank as it get low. No need for gas/coal/wind/solar.

Energy crisis solved.

(sarcasm off)

2-Star | September 26, 2013


Please read the First Law of Thermodynamics (the one involving the Law of Energy Conservation). Then present your idea to your local high-school or college physics teacher.

Timo | September 26, 2013

Eh? Local kindergarten janitor is probably the one which he should present his idea. He could then explain him why it doesn't work (accustomed to deal with children so can talk with very simple ways, and enough practical mechanical experience to actually show why it doesn't work). High-school or college physics teacher would just laugh to him.

Timo | September 26, 2013

In the mean time: Harold, try to answer this simple question: where does the energy come from to fill that air tank? When you can answer that question it is self-explanatory why it doesn't work.

2-Star | September 26, 2013

Before Brian H steps in, it's "Almost too simple." not "Almost to simple." And I'm afraid, Walter, that you don't appear to be a genius.

David70 | September 26, 2013

You people just don't get it. But it is Walter's fault, as he didn't give all the details.

He has discovered a way to create a wormhole from the front of the car to somewhere in the vacuum of space. It's really a gigantic breakthrough, as most wormholes can only be created using unthinkable amounts of energy and power. As air is sucked from the front of the car to the vacuum, it turns a turbine which powers a compressor. In addition, it eliminates practically all aerodynamic drag. Enough said.

Sorry for the sarcasm, but I'm just so sick of all the perpetual motion schemes that people feel they're the only ones smart enough to figure out. For a long time now I've ignored these threads, but I couldn't ignore this any longer.

olanmills | September 26, 2013

YES! I knew there was a reason I came back to the Tesla forums after a long absence. It was to see "great ideas" like this!

I literally smiled when I saw that the "Charging System" had been bumped back to the first page.

This great. Walter went through the effort of digging this out of the depths.

holidayday | September 26, 2013

Walter: "Air Tank
Air Compressor (powered by an air-powered engine) Air Compressors always have there own air tank. So there are two air tanks."

You have a problem with air pressure in the two tanks. If you empty one tank, and use the energy to run the compressor (which is not 1005 efficient), you would only have enough energy from that to fill the other tank. You would NOT have enough energy to fill the other tank AND run an alternator to run the car. Plus, due to frictions, you would not be able to fill the other tank completely.

You mention an "air powered engine", but you do not say where THAT engine is getting its energy from.

You are missing the point that a) There is no unlimited energy and b) Tesla has thought of ALL options, and at this time, the battery alone is the best option (charged by external electricity)

holidayday | September 26, 2013

edit for above : (which is not 100% efficient)

olanmills | September 26, 2013

Walter, I think I have multiple ways to describe why what you are thinking won't work, but here are the simplest ones:

1. If it involves any type of "free" energy, it won't work. This should always be your first thought, but if you're stubborn, read on.

2. Your proposed system requires no special new technology or any difficult to obtain tools or components. It should be relatively simple for you to draw up plans and build a working model (that could power a light or radio, for example). Get a friend to help you as a little side project on the weekend. (Be careful compressed air tanks though!). (Now of course, I advise you not to do this, as it will be a waste of time, since your idea won't work, but you can still try and learn for yourself).

3. Given, point #2, that your idea is relatively simple and requires no new technology, and that the benefit is so incredible compared to the effort required to produce your system, somebody would have done it already. As BlueShift mentioned, if your idea worked, why wouldn't we simply build power plants like this? The answer of course is because your idea is nonsense.


Hopefully your will be able to understand this. As soon as you connect your system together the air pressure in the whole system will equalize and no more air will move. The only way to repressurize one or both tanks would be to power the air compressor with another outside source of energy.

Now if you answer that the air from the starting air tank won't be released all at once, then pressure equalization will just be slower.

David70 | September 27, 2013

OK. I guess you're enlisting the aid of Maxwell's demon.

I give up. It still ain't going to work.

TSLAholic | September 27, 2013

I came across this bad boy earlier today and immediately thought of this thread! Here's what it takes to pump out 50 amps at 250 volts while on the go.
If we follow Walter's thought process, the only thing that should stand between reality and his brand new idea is a PTO hookup to the Model S gearbox.
This setup completely bypasses the air tank idea. Here's how: similar to initially filling the air tank with compressed air, all we have to do is initially get the car moving with this contraption hooked up to the tow hitch (sold separately). A little bit of power would be used up from the battery every time the car needs to get moving, but the energy would be put right back into the battery upon deceleration since: Once at motion, a body tends to stay at motion (like, duh!), so... once we let go of the accelerator pedal, the inertia from the generator pushing the car forward would replenish the initial battery power loss. As long as you keep your foot on the accelerator (single pedal driving), the generator will continue pumping out 50 amps of current @ 250 volts necessary to perpetually charge the battery pack. Visualize!

Brian H | September 27, 2013

No usable energy. Similar to your brain power.

Brian H | September 27, 2013

No, it will not pump power right back in. Losses everywhere. It's The Law. Regen is at most about 80% effective, to start.