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Battery tech

Hello all.

Just read from autobloggreen about some new battery manufacturer called "Planar Energy". (http://green.autoblog.com/2010/07/27/planar-energy-to-begin-small-scale-...)

They seem to have tech for pretty good Wh/kg batteries. From one of their pdf (http://www.planarenergy.com/Press%20Releases/Technology%20Review_%20Safe...)

"One of them combines lithium manganese oxide with other ions, and operates at about three to five volts with a charge capacity of 200 milliamp hours per gram."

Calculating that as 3.5V * 200mAh/g you get 700mWh/g or 700Wh/kg. to put that in right context: Roadster battery: 450kg. Drop 30% off as supporting structure: 315kg battery * 700 = 220.500kWh battery. Nearly four times as much as current tech is. That would allow roadster to go 200 * 4 = 800 miles with one charge.

Math and physics. Middle school level. Conservation of energy. Newton. Bernoulli. There is no such a thing as something for nothing.

Ask what his engineering/physics credentials are.

The idea of windmills/wind turbines used to help power vehicles has been around for many decades. At least 30 years ago (and numerous times since then) I would have students (not physics students, but enquiring minds) come into my office to ask about this. My normal response after unsuccessfully trying to convince them it wouldn't work was to tell them "Take the necessary physics and math courses first."

The idea doesn't have to be restricted to electrical vehicles, but if it could work would assist petroleum powered vehicles as well. If anyone had successfully managed to come up with anything like that, we'd know about it by now.

I can't believe that every major automotive company doesn't have (or at least have access to) wind tunnel testing facilities. Even if they didn't have a working prototype, they can do wind tunnel testing and computer modeling.

Of course, it is possible to extract energy from the wind. E.g., a sailboat, and you can even use it to make progress into a wind using "tacking". However, that would require the ability to change your direction at will. If you could make a "smart metal" car that could reform itself for different conditions (i.e. effectively make it a sail), it Could (not necessarily would) be possible to assist the forward motion with wind energy. I wouldn't count on anything like this in the foreseeable future.

Sail boats work only because you can tack against the wind without having to stay on a road, you can go faster than the wind occasionally when you go in a certain small range of directions, or you go slower than the wind. All other times the sail would slow you down.

Turbines will not work. Energy loss.

William13,

Exactly.

A turbine has internal spinning blades and rotors. The incoming air pushes to make them spin. That slows the air down, and pushes the car back. The turbine spins and pushes the car forward -- but less than the air pushes backwards.

(Jet turbines not relevant, of course, since they burn fuel and force it out the rear nozzle at huge velocity.)

Basic rules to follow:

1) fact: we can't create energy, we can only convert it.
2) question: where does the energy originate?
3) question: is the energy just lost otherwise?

Following those simple basic rules gives you immediate result is something wannabe perpetual motion machine or not.

And no, wind turbines in car do not fall in category 3. Energy gaining suspension does.

by using intake holes you are not incresing wind resistance because you are not changing the over all size or shape of the car it self. just letting the air go though not around.

like i said before solor pannels are not cheep. luckly they are steadly improving both in price and efficiency. (nano tubes are great) and when the price becomes more affordible. 5% is still another 5%. with nano tubes meybe much higher. i dont know about you but if i can go 315 miles rather than 300 that is an improvement.

@toxic therapy, you are still better off making car as aerodynamic as possible than making intake holes for turbines. Unless you are using some otherwise lost energy source you do not gain anything.

That "directly downwind" youtube clip you posted has nothing to do with what you are proposing, it has a simple basic physics explanation. That same setting wont work if you try it other way around (upwind, which is the case of car pushing thru air), because it is the wheels that run the propeller and not vice versa. What you are seeing is a basically a rotating sail and neat physics trick. As people here have said sailboats on road do not work very well.

Forgot to say that any change in car shape that changes the airflow changes the wind resistance. Everything counts. Intakes are no exception. Turbine inside or outside of intake cause exactly same drag.

Right Timo.

And we're talking about apples and oranges here. Not the same thing.

Toxic Therapy.

The nice little video is showing the extraction of energy from wind, an existing source of energy. Not recovering energy by holes passing through the vehicle.

Furthermore, if you place holes through the car, it will actually increase the drag since there would be an increased turbulence, as opposed to smooth laminar (layered) flow around the body of a well designed car.

I can assure you that on a calm day, if you were to start pushing one of those wind turbine cars, it would be a lot more difficult than pushing the same car without the wind turbine on it at the same forward speed.

OK, The arguments against the wind tunnel thing that surfaces now and again sound "collegiate" enough for me. I accept that wind tunnels are a "no go". Rcognizing the fact that most of you folks are pretty "collegiate" to begin with with. At least you sound so to me, But actually how would I know?

Now getting back to the DBN Energy battery. What are your opinions on the "battery tech" here. Could something like this be likely or could it ever be likely. In other words, again, have we probably reach the outer limits in battery tech or is their a good possibility that we have just scratched the surface on battery tech.

Same question on very compact solar panels?

Thanks for any discussion. Enjoyed the lively discussion on wind turbines etc.

Solar max is about 1kW / m^2 depending where you measure it. It can't get much higher than that unless you move outside of atmosphere and closer to Sun, like in Venus or something. Then you need to calculate in Sun angle, bad weather, shadows etc.

Basically it is not worth the cost and added complexity in cars. Not now, not ever. For houses it's different.

And to the question about batteries theoretically there is still significant room for improvement. Right now Tesla makes the highest density battery of any manufacturer in KWH/KG, but as we have seen Panasonic has a newer battery with about 20% more capacity. I think we will see a lot of imporovement here over the next few years. But for active R&D there needs to be a realisitc payoff and I believe the electric cars will provide the need and our researches will provide the way.

On solar I agree we can make it work for a home with the larger roof area. But even if a car were coated with the best thin film available and one parked in the sun all day you would gain enough energy to drive about 5 miles. Sunlight is just too diffuse for transportation. At least for normal people.

The reason I include that caveot is that ther are a few demonstration solar cars with a large rrof area, room for one person, normally laying down that are VERY aerodynamic with high pressure bicycle tires, very minimal acceleration, no hear or air that have made some demonstration drives. See http://solarcar.engin.umich.edu/about-us/the-car/ But at a cost of \$1,000,000 it makes the Tesla Roadster look like a real bargain.

@Timo and DHrivnak, Thanks for the interesting replies. No as long as I have been reading these post I am way ahead of speaking about solar on cars. Think we have discussed something along this line before, if so please excuse the redundancy, but I was speaking of condensed solar panels that one might buy when bought the car that could be set up in the back yard ar on the back roof with relatively small size . For examle set up on steel post with maybe an eight or ten foot suare surface area. This solar panel working independently of house system and just specifically for charging the car at night. Just sort of a kit type arrangement when you bought the car. Could this be a possible doable in future.

Also Timo did you pretty much concur with what DHrivnak said about potential future battery development or do you think we have reached the outer limits on this development.

Thanks again for the informative stuff.

We are far from limits. Lithium-ion theoretical energy density is higher than gasoline. Combine that with EV efficiency and you get 1000 mile range car with battery pack size of small suitcase. We are nowhere close to that yet.

And Searcher,

The advantage of using a condenser/concentrator with solar cells is that can get by with a much smaller array of PVs.

The major disadvantages are that the PVs have to survive much higher temperatures, and that they won't work well (at least not very) on overcast days.

Searcher, there is no free ride. The amount of solar is limited but the sun and quite diffuse. Full sun is about 100 watts/sq ft. So if one assumes 100% conversion efficiency, a solar array 10x20’ (200 sqft) you get enough energy to drive 8 miles. With current PV technology at 25% you get 2 miles of range. Now this is in Arizona at noon. Yes people are working on concentrating the energy but one is still limited to 100 watts/sqft.

Have you considered taking a course on physics?

@Timo, Very glad so much potential left in area of battery deveopment. This was very cool information. Thanks

@DHrivnak. Yes I took physics in high school but thats been awhile ago. Am currentyly involved in an online physics course. Haven't you noticed , "You guys are the instructors". Oh yes one of the big lessons I have had "drummed" into my head is "there is no free ride". But somehow I seem to keep wanting to circumvent this basic. I am getting it though, you won't believe what I have learned just by reading and asking a "jillion" questions on this site.

Just thought it would be so cool to buy relativly small solar charger kit just for the car. Didn't know if this would ever be a doable or not. Know thaat people charge their Evs off the large home systems and I realy like this.

Actually Searcher, one thing you could review that might be helpful would be units/dimensions. Especially those of energy, power, intensity and related electrical units of current and potential difference. That might give you a better idea of what may be practical for energy storage in batteries, and available energy from sunlight.

Well, Searcher, I would probably trust the engineers, scientists, professors, and laboratory workers who have studied and tested all these theories for decades and centuries.

Sure, to some minds, it might look like the wind moving past a car could be used to capture more energy, but years of study and testing by people who have done nothing but testing and questing, have shown the same thing over and over and over.

Any time you pull energy out of a system, it takes MORE energy to compensate. There are ALWAYS losses. You cannot make energy off of suspension movement, turbines, or anything without having to put more energy into keeping the car moving.

Just because someone says it is a physical law, does not mean that someone has not tried to think of a way that no one else has ever thought of. It's been tried so often that the smart people just accept that it is really, really, a physical law.

It's the students who skipped lab and never did any actual testing that still think the impossible might be able to be done, after all.

It’s really a valuable idea. Tesla motors should really look into this one. Can work wonders for saving a lot of money and energy on making cars. :)

I really liked the prospects Timo gave about the future of batteries. The sooner the better and this thing will be "game over" as far as ICE and EV's.

@landon.bruno: Exactly what idea were you referring too?

What might be the general consensus on a stepping stone approach to EVs. To get a very fast embrace (\$\$\$) from all of USA, introduce a Tesla with out a fixed battery, but instead, interchangeable battery packs. You are able to stop and get a "full tank of battery" just as you do with your fossil fuel vehicle, at least until battery technology make this unnecessary. Additionally, these are leased, not purchased, and should greatly reduce the initial cost of my new Tesla. Tesla owners would stop by a participating Tesla Dealer or "Marathon" type service station and be able to swap out their mostly used battery pack for a "refill" AND get a credit for unused remaining charge. New technology battery packs are introduced as science progresses and routed into the "refill" battery stream as the older technology packs are pulled out and recycled - funded by the lease cost structure. Recharge/Refill location pop up like dandelions along routes frequented by Tesla cars. Sign me up!

Project "Better Place" crops up yet again.

That concept is being tested over in India I believe. We'll see how it does

Once again the idea of leasing batteries pops up. The basic economics are that leasing always must cost more than buying.
Someone has to own the batteries and lease them out. All that requires capital - to buy the batteries, pay interest on the money spent, do the actual leasing, and, not least, try to estimate
income and value over an extended period of time, which is not exactly known. I would have zero interest in owning batteries to be leased by others. Its an enterprise chock full of uncertainties.
I don't know how long the batteries will last, how do I lease ? by mileage or time or what? What will the batteries actually be worth 5 years down the road? That will depend in large measure upon what kind of batteries are available 5 years from now - their intial an long term costs. Guess what? I don't have any idea. I think you can see that rational leasing, in which costs are accurately known, is the only situation that allows one to lease at or near true cost or value. We ain't there, so battery leasing would have to have pretty high rates to avoid losing money if much cheaper and/or better batteries show up within the lifespan of the batteries that I'm leasing. In other words, battery leasing is not only high cost, it simply won't be available. It's way too risky
for anyone to try.
I did read a proposal to electrify the highways with embedded
recharging segments every so often, that worked the same way as
parking pad rechargers do. The cars would have minimal sized batteries and recharge for the few milliseconds while travelling over these recharge segments embedded in the highway. That is actually rather clever. Batteries will probably get cheaper and make this system obsolete before it's ever built, however.

project better place is actually putting serious money in a "leased battery" business. They will start in Israel this year with a nation wide network and 100'000 cars, as well in Hawaii. The initial investment is shocking (\$1.1m for 7 cars in Hawaii). Should improve with growing number of cars. The lease rate depends on the miles driven, so they must link to your car's computer. Actually, they own the computer (they wrote the software), the comm network and the charging+swapping stations. This is quite an intrusive approach and might be not acceptable to some customers.

Volker;
there's a danger of dragging or even locking down battery progress if leasing became dominant, I'd think. Otherwise the lessors would be periodically writing off major chunks of inventory. So the pressure would be on to "prolong" their use and usefulness, which would mean going slow on new tech.

New electrode design "carbon sponge" for capacitors, able to reach energy density nearly the same as lead acid batteries. Not clear what the units are: by weight? That still leaves the caps HUGE per unit charge.
http://www.zdnet.com/blog/emergingtech/new-carbon-sponge-could-revolutio...

Liquid batteries that can have around 300-400Wh/kg and 600-800Wh/L energy densities.

Solves the competition between all other competitive techs. Can be pumped in like gasoline if needed (once depleted battery has been pumped out) == battery swapping, charged if preferred, costs fraction of what current batteries cost, do not need huge supporting structures. And so on and on.

Sounds familiar...Demolition Man, anyone? Reality catches with SciFi.

@Timo;
Interesting! About a 3-5 yr timeline if it's for real:

The target of the team’s ongoing work, under a three-year ARPA-E grant awarded in September 2010, is to have, by the end of the grant period, “a fully-functioning, reduced-scale prototype system,” Chiang says, ready to be engineered for production as a replacement for existing electric-car batteries.