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Conductivity and Energy storage?

Discussion in 'General Electronics Discussion' started by Moha99, Mar 23, 2012.

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  1. Moha99

    Moha99

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    Nov 18, 2011
    I was studying a few things about conductivity and I wanted to apply some ideas on it.
    Needed to make sure before I would apply this that Im on the right page.

    Now I found out that current can increase of the copper wire I use it a bit larger than the previous one is that true? Also if cooled down I could get less chances of current decreasing and also length the shorter the better is that all correct?


    One more thing what are the best way other than batteries to store energy that also charge and discharge at the same time? And do you think this feature could be available later on in the future for rechargeable batteries?
     
  2. timothy48342

    timothy48342

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    Nov 28, 2011
    Moha,

    I think you got it. (as far as conductivity)

    Resistance is the inverse of conductivity.
    Current dependes on resistance. (or conductivity)
    When talking about changes in current as a result of changing wire construction, you almost have to say something like, "with voltage held constant" (I am being really picky there, I know)

    larger wire (that is thicker wire) ---> less resistance, more conductivity, and with voltage held constant, yes, more current.

    shorter wire, same as thicker, yes, you got it.

    Wires that are cooled down.... hmmm.. If you could KEEP the wire cool, then you could keep the resistance lower, but remember the wire is turning some energy into heat, and dissapating what it can. Cooling it to begin with does nothing. (unless you can cool it to superconducting temperatures)

    As far as electrical energy storage, a large capacitor can work similar to a battery. The newer supercaps are getting bigger and bigger (and cheaper). Also the work they are doing on hydrogen storage cells looks promising. (it looked promising a few years ago, maybe they are in use now, I don't know)

    Remember, though that with any storage device you can't add to it and remove from it at the same time. If you have a bucket of water with a hole in the bottom, you can increase the level of water by filling it, you can decrease the level by letting it empty, you can keep it in balance, but you will never ever increase and decrease the level at the same time.

    When it comes to charging batteries, you can design a circuit that makes it appear to the end user that for all practical purposes the battery is charging and discharging at the same time, but as a designer, you must realize that this is not happening.

    When you start your car, you use battery power. Once started there is enough power from the alternator to run the car and all the accessories and recharge the battery and keep it topped off, but the car is running off the alternator not the battery.

    You can turn on your laptop and run it off the battery for a while. When you plug it into the mains, the charger has enough power to recharge the battery and power the laptop. The laptop is running off the charging circuit, not the battery.

    As an end user of a car or laptop you can imagine any sort of magical flow of electricity you want. If you as a designer start thinking of energy flowing in and out at the same time and try to make seperate pathways and limit direction of flow and all that.... I think your heading down a road that doesn't go anywhere.

    You have a friend that works for a battery company. Tell him that someone online (lots of people online) told you that "technically a battery is either charging or discharging or staying steady and never charging and discharging at the same time," and see what he says. Also give him a link to this site and invite him to join and discuss.

    --tim
     
  3. Moha99

    Moha99

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    Nov 18, 2011

    Thanks Tim for all that info! I was just wondering about this diagram and I'm trying to understand how batteries work I understood how chemical reactions transfer electrical but before I go on check this diagram out:

    [​IMG]


    You see Cathode + and Anode - terminals from the top correct? What about if we added opposite sides at the bottom? charging them keeping the chemical reaction constantly going on and the oxidation process keeps going? I understand this process if possibile could shorten the life of the battery but if its possibile man its worth it!

    Ultracapacitors for me are the future but the thing is they have low voltages if the voltages bounce up x10 time it will be amazing! But I guess Ultra caps cant discharge and charge the same way huh?

    I imagine electricity as water sometimes but that complicated quick vanishing water that has sooooo many requirements to work perfectly.

    But discussions like this could possibly bring light to new ideas and methods this world of energy is vastly complex I honestly believe there is truly so much for us to understand!
     
  4. Moha99

    Moha99

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    Nov 18, 2011


    If you would look at part 1:19 the charge and the discharge process its like a closed circuit well the charge is flown between the Anode and the Cathode.

    I was researching the best batteries in the industry and so far I found it lithium ion batteries are the best.

    So I thought about the terminals and how batteries are charged and discharged and I think there could something... I feel it is possibile to charge and discharge in the same time but not by charging it in the same terminals as discharging it...

    I don't know Im just brainstorming of ways their could be a possibility to charge and discharge a battery. I imagine a battery jut like a TANK that causes a chemical reaction the gives electricity as an product as well!

    What do you all think?

    I've been sitting on my computer researching about and conductivity and energy storage.
     
  5. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

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    Jan 21, 2010
    Batteries CANNOT charge and discharge at the same time (and you wouldn't want them to even if they could).
     
  6. Moha99

    Moha99

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    Nov 18, 2011
    Why wouldn't I? Im asking to understand more and get a better image of this.
     
  7. Moha99

    Moha99

    261
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    Nov 18, 2011
    The thing is I understood why we can't do it and all but If we could the amount of possibilities would be endless.

    I understand it sounds crazy but doesn't all ideas at first sound that way...
    But I would like to get a lithium battery and open it up with safe tools and study it part by part!
     
  8. cjdelphi

    cjdelphi

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    Oct 26, 2011
    You might be thinking of a Capacitor, you can take energy (small amounts) and fill a capacitor, the only difference being, a capacitor charges and discharges all it's energy in only a few MS, while a battery can not.
     
  9. Moha99

    Moha99

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    Nov 18, 2011
    I know that. But using supercap's they have a capacitance up to 2000FARADS! imagine the amount of energy we can store and charge it in a short time and discharge it :D!

    Do capacitors charge and discharge in the same time? I'm guessing it does...
     
  10. Moha99

    Moha99

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    Nov 18, 2011
    I think UltraCapacitors are what I believe somewhat inspired from batteries.

    [​IMG]

    Look at the last right digram electric double-layer capacitor also known as electrochemical double layer.

    "electrochemical" the key reaction on batteries isn't it? electrochemical cells?
     
  11. cjdelphi

    cjdelphi

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    Oct 26, 2011
    Supercaps may vary between manufactures, you'd need specs of the actual cap to determine that, i've seen some large caps including ones that act almost like a battery in flashlights...

    My only concern with supercaps is charging them, take a 2amp/h AA battery, let's suppose you could charge it via USB (linear for argument sake) 2amps/500mah (USB supply) it would take 4 hours to charge it.. (500ma/h)

    if you had a Super Capacitor, you should be able to charge 2 amps worth (hypothetically) in only a few seconds, but, the power supply can still only deliver 500mah (meaning 2 hours to charge the supercap)

    So yes they're great but what about the heat and technology behind charging them? people going oh well in that case i'll buy a 120volt cap connect it through a rectifier diode and charge it from the mains supply in only a few seconds... i mean how many adapters/power supplies could charge a 6volt super cap in only a few seconds?!
     
    Last edited: Mar 24, 2012
  12. cjdelphi

    cjdelphi

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    Oct 26, 2011
    Batteries came through inspiration from mr volter, using a stack of plates (1.3v each) a capacitor came much sooner through a Laden Jar ...
     
  13. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

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    Jan 21, 2010
    The problem with a battery is that they always take more power to recharge than you get back -- often significantly more.

    Clearly this would mean that simultaneously charging and discharging one would be equivalent to wasting energy when you have the option not to.

    Fortunately, because current can't flow both ways in a piece of wire, you can't simultaneously charge and discharge a battery.
     
  14. Moha99

    Moha99

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    Nov 18, 2011
    Now thats just sad...
    If there was a way to charge and recharge at the same time it would've been fantastic!

    I guess capacitors are the way to go huh..?
     
  15. Moha99

    Moha99

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    Nov 18, 2011
    Now if capacitors can charge and discharge that quick!

    How can I calculate the required amps for the capacitor lets say if I have a 5F capacitor?
    And how much charge is held from it and how long will it take to discharge and etc...

    Do you all have any ideas how?
     
  16. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

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    Jan 21, 2010
    I'm not sure why it would be fantastic.

    If my car could simultaneously be in a forward and a reverse gear it would also be fantastic!

    Capacitors will have some sort of limit on the charge/discharge rate. They have an internal resistance and will be heated by current flows within them.

    A current of 1 Amp flowing into a capacitor of 1 Farad for 1 second will raise the voltage by 1 Volt.

    Likewise 1 Amp being drawn from a capacitor of 1 Farad for 1 second will drop the voltage by 1 Volt.

    The energy in a capacitor (in joules) is (1/2)V^2C (V in volts, C in Farads)

    For discharge see above.

    Most often you're not going to be charging nor discharging at a constant current. There are other equations and approximations which deal with (say) discharging across a constant resistance, or charging from a voltage source in series with a resistor.
     
  17. Moha99

    Moha99

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    Nov 18, 2011

    For my theories this feature would be fantastic.
    But thanks for the CAP. information it useful as well :D
     
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