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Thread: Battery Capability

  1. #1 Battery Capability 
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    I know batteries work chemically.

    Assume you have a common 1.5v Alkaline D-Cell battery (20.5Ah?). Now assume you have a small 1.5v DC motor. Then you have a gear/pulley system that converts the output of the motor so that it can lift a platform up and down at the motor's optimum speed.

    If you were to place a 500-ton block onto the platform, then turned the motor on, what information do you need to know how far that D-Cell could lift the 500-ton block? You'd lose a good bit of efficiency to all the friction, of course.


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  3. #2  
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    In reality there would probably not be enough power to even overcome the friction of the gearing.

    You need to know the torque rating of the motor, at a particular current, and the stall torque & current, from that you can work out the grearing required then you can estimate the time for the battery to flatten and thus calculate the lift arrived at (but you need to take into account friction).


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  4. #3  
    Forum Junior SolomonGrundy's Avatar
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    Quote Originally Posted by Megabrain
    In reality there would probably not be enough power to even overcome the friction of the gearing.

    You need to know the torque rating of the motor, at a particular current, and the stall torque & current, from that you can work out the grearing required then you can estimate the time for the battery to flatten and thus calculate the lift arrived at (but you need to take into account friction).
    are you a lama?
    Solomon Grundy
    In 1944, this creature rose from the swamp, with tremendous strength and some dormant memories that for example allowed him to speak English, but not knowing what he was, and not remembering Cyrus Gold or his fate. Wandering throughout the swamp, he encountered two escaped criminals, killed them, and took their clothes. When they asked him his name, he simply muttered that he had been born on Monday. Reminded of an old nursery rhyme about a man born on Monday, the thugs named the creature "Solomon Grundy".
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    Quote Originally Posted by SolomonGrundy
    Quote Originally Posted by Megabrain
    In reality there would probably not be enough power to even overcome the friction of the gearing.

    You need to know the torque rating of the motor, at a particular current, and the stall torque & current, from that you can work out the grearing required then you can estimate the time for the battery to flatten and thus calculate the lift arrived at (but you need to take into account friction).
    are you a lama?
    Oh God give me strenght! Solomon here is the link to the philosphical section of the forum. Please use it!!!
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  6. #5  
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    Fuck of solomon, I am answering a serious question here.
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  7. #6  
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    Quote Originally Posted by Megabrain
    Fuck of solomon, I am answering a serious question here.
    since when?
    Solomon Grundy
    In 1944, this creature rose from the swamp, with tremendous strength and some dormant memories that for example allowed him to speak English, but not knowing what he was, and not remembering Cyrus Gold or his fate. Wandering throughout the swamp, he encountered two escaped criminals, killed them, and took their clothes. When they asked him his name, he simply muttered that he had been born on Monday. Reminded of an old nursery rhyme about a man born on Monday, the thugs named the creature "Solomon Grundy".
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  8. #7  
    The Doctor Quantime's Avatar
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    I'm sure a lot of people here would appreciate it if you did not be so insulting. Solomongrundy may not know a lot about some things, he may even troll at times. But there is absolutley no need to say that to him, you are demeaning your intelligence in my eyes, and that may also be evident in other users. For your own good, cease doing so.
    "If you wish to make an apple pie from scratch, you must first invent the universe". - Carl Sagan
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  9. #8  
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    Fuck off swiveller this is a serious thread, pm me if you like but keep out of serious threads, go and play with yourself in the bathroom.
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  10. #9  
    Forum Bachelors Degree Shaderwolf's Avatar
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    back to the discussion?

    how bout a bigger battery and a smaller block?

    the real question is: "what information do you need to know how far that [battery] could lift the [x]-ton block?"

    Megabrain started explaining, and was than rudely interupted, obviously he's not in a good mood. There has been bad things happening here in my absence.
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  11. #10  
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    Ok you need the manufacturers sheet which details the discharge characteristics of the battery, 25Amp hours is the standard discharge at a given rate, at a lesser rate the discharge time will be more, then the INternal resistance of the battery will have an effect.

    As you apply a greater load to the battery it's voltage will drop due to this internal resistance. You then need to know how much useful torque you can get from the motor at a particular voltage. SO when you know the max (pre-stall) torque and the battery capacity this will allow you to multiply the torque whilst dividing the time until you get to your two tons (or whatever) and there you havwe it. Test the system without the full load to measure energy lost through friction.
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    Forum Bachelors Degree Shaderwolf's Avatar
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    Another thing I have always wondered. This might be a little off topic, but... how do you find resistance of a generator. I learned that cranking a generator gets harder because of electric friction? I don't understand why for one thing... also, I would like to learn how to predict that electric friction.

    I wanted to see how much energy can be "recycled" from a simple motor bike...
    ex:
    I have a bike with a motor... simple pedal bike that I worked on.
    Now, I put a few generators wich use the rotation of the wheels to turn, and are hooked up to a second battery. I want to measure how much energy I "recycled" if electric friction causes the motor to have to work harder, is that "harder" the same amount of energy recycled? Is there any energy saved in the process?
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  13. #12  
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    If you turn an 'unloaded' generator you should only experience air, gearing and bearing frictions.

    If you apply a load (say a light bulb) then you will need to crank with more power. It is possible to calculate how much more power BUT you need to know a whole bunch of things about the generator.
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  14. #13  
    Forum Bachelors Degree Shaderwolf's Avatar
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    O.K. would charging a battery "load" a generator? where can I learn more? I'm pretty sure I can handle most mathematical equations I have a 2.5 years of calculus experience.
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  15. #14  
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    If the generator is passing any current into a load then yes, so if the battery is charging the generator will load the powersource.

    There is(are) no simple equation(s) for this, you need to either take sample data and extrapolate for a particular generator or go through the design of every little piece of the machinery. from the copper wire to the bearings magnets temperature etc etc.


    In a simple system assuming no losses:-
    ergs is the mechanical work joules is the electrical energy that will be the heart, work out how many joules you ned (1 joule is 1 watt second) then convert to ergs to give mechanical energy required. If you have Calc under your belt it should be a doddle!
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  16. #15  
    Forum Bachelors Degree Shaderwolf's Avatar
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    Before I start, what do you think? Charging a battery than will cause friction... If I bought a generator, will the extra energy needed to push the bike forwards because of the electrical friction equal the amount of energy put in the battery?
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  17. #16  
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    Right imagine not moving then no energy into battery and no extra effort, the battery will load the generator from the point art which the genny outputut voltage equals the battery voltage, you will come to a point therefore where masses of extra effort will only result in a tiny increase of speed but with all the extra effort being turned into electricity, once the genny has slowed to a poitn where it's ouptut is below the battery voltage it will feel like the brakes have been taken off.

    What are you actually trying to achieve as an end result?
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  18. #17  
    Forum Bachelors Degree Shaderwolf's Avatar
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    It was actually just an Idea I had. "ways to improve energy efficiency" put that and some solar panels on your electric car and you'll have to fuel up less? I was actually thinking of the air car. I want one. I might not even drive it. I'd just work on it.
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  19. #18  
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    Have a look at the Australian solar powered sony/Honda? competition.

    I believe NASA has a plane that can fly on only solar power but it crashes just before dusk....
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  20. #19  
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    I just wanted to be more energy efficient. I don't think pure solar cars will get very far. I think that we should recycle energy as much as possible though. I could tell you what my idea of an impossible future that I would want could be. Every motion has something hooked up to it. Cloths, doors, everything with little gears so that when you move, you make energy, which is stored in a battery. One person wouldn't make much... but imagine the energy made by the entire combined population of every developed country in the world. It's a little unrealistic, I know... but it's a dream.
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  21. #20  
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    I use a bicycle when and where I can, I will be buying a car in the next week or two which will be an 1100cc car, I will be stripping out all the uneccessary weight from it all bar the driver's seat, every ounce I can shift!
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  22. #21  
    Forum Junior SolomonGrundy's Avatar
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    Quote Originally Posted by Megabrain
    I use a bicycle when and where I can, I will be buying a car in the next week or two which will be an 1100cc car, I will be stripping out all the uneccessary weight from it all bar the driver's seat, every ounce I can shift!
    do you have monney are you rich?
    Solomon Grundy
    In 1944, this creature rose from the swamp, with tremendous strength and some dormant memories that for example allowed him to speak English, but not knowing what he was, and not remembering Cyrus Gold or his fate. Wandering throughout the swamp, he encountered two escaped criminals, killed them, and took their clothes. When they asked him his name, he simply muttered that he had been born on Monday. Reminded of an old nursery rhyme about a man born on Monday, the thugs named the creature "Solomon Grundy".
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  23. #22  
    Forum Bachelors Degree Shaderwolf's Avatar
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    I ride my bike in the summer. If you remember from one of my recent posts... I moved from Las Vegas a couple of years ago to Wyoming. Yesterday morning it was -12 farenheit... what is that in celcius? ...around -23. I'm poor right now, because I'm going to college. My car... is horrible. I bought it from a family member for $200. It's a 1986 Toyota Camary. Horrible gas mileage, because I can't afford anything else. I feel ashamed. I do what I can though.
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