how do you make something battery powered?
94049
That depends. A lot of consumer electronics use a "wall wart" -- a transformer that converts AC to DC power. These usually have a coaxial plug in the device. Look at the transformer and see if it says something like 6VDC 200mA. It will also show which part of the plug is + and which is -. Now, if you want to run off a car battery, you can buy a car adapter that will fit these plugs. Or, you could buy a plug and a battery holder if you supply the right batteries. But the higher the mA rating (milliamps, 1/1000 of an amp) the less the batteries will last. So something running off 6V would require 4 D cells, for example and the right plug. Also if the adapter says AC you may not be able to use this method -- it would depend on the internal design of the device. Note that doing this has some risk of damaging your device though. Be careful and make sure you know what you are doing. If you don't know what you are doing, get someone  who is an electronics hobbyist (like a ham radio operator or an electronics student or teacher at a local school) to help you.\n\nAnother way is to use an AC inverter. This takes DC power (usually, but not always from a car battery) and converts it to plain old 110V. These have gotten much cheaper recently. If you aren't using a car battery, you can find units from Black and Decker and others that have gel cell batteries in them so you just carry around 110V AC. These go by names like "storm station" and you, of course, have to recharge the battery from time to time.
472476
You need something iron (like a nail) wrap the wire around to make an electromagnet. You could wrap the wood lengthways with some wire and then wrap another wire shortways around the assembly and hook to the battery but an iron core is much better. \n http://www.energyquest.ca.gov/projects/electromagnet.html\nBTW You do have most of the parts to make a simple radio receiver also.
189432
Purchase a battery-operated boyfriend
726624
A bicycle seems like a good base. If you connect it to a automotive alternator and 12v battery you can produce and store power using cheap available items.\n\nIf you want 220 volts, you can buy inverters that produce it from a 12v battery, again using "off the shelf" equipment.\n\nHappy cycling cause I think you are going to find the human body quite limited at power production.\n\nps, To build something using the items I suggest would mean supporting the bicycle, hopefully you could use the wheel as a pulley without its tire and drive the alternator (having the gears of a standard bicycle being better than an exercise bike to try and match the ratio you need) Since we're not talking much power, the drive belt wouldn't need to be too technical but you may want to change the pulley on the alternator to something wider to match the wheel. If your bicycle support is bolted to a piece of plywood laying on the floor, you should be able to bracket the alternator to that plywood and keep the belt tight enough.\n\nThe electrical connection is fairly simple, connect the big lug on the alternator to the car battery +ive and the casing to the -ive. You will need to connect a small indication light between the small lug and the +ive as this is part of the charge circuit. I suggest a ammeter in the circuit to prove the doubting people on here they are wrong and that you can drive a charge current into the battery but don't buy one with too big of a range :-)\n\npps Try to select a low power alternator (off a small car). \n\nppps If you want to do this without incurring a large expense, you need to make best use of parts that are readily available and do the engineering to suit. If this is not your best subject, you may need to seriously consider whether you want to waste any time any money attempting it.
167146
turns light into energy.\n\ncharge a battery for free
329463
Home made, a 24 volt car battery and jumpercables, a piece of iron rob work well. If my use a cattle prod.That is what I use grabblin for catfish.
29248
here's what you need:\n\n1.18-gauge copper wire (smaller gauge will work too,2. but 18-gauge is stiffer)\n3.Wire clippers\n4.Steel paper clip (Some people find that a 2-inch 5.strip of zinc works better) \n6.Sheet of coarse sandpaper\n7.Lemon\n8.Help from an older friend or an adult\n\n\nhere's what you need to do:\n\n\nHave your older friend or an adult strip 2 inches of insulation off the copper wire. Clip the 2 inches of bare wire with the clippers.\n\nStraighten out the paper clip and cut about 2 inches of the straightened steel wire, or use a 2-inch piece or strip of zinc.\n\nUse sandpaper to smooth any rough spots on the ends of the wire and paper clip or piece of zinc.\n\nSqueeze the lemon gently with your hands. But don't rupture the lemon's skin. Rolling it on a table with a little pressure works great. \n \nPush the pieces of the paper clip and the wire into the lemon so they are as close together as you can get them without touching.\n\nMoisten your tongue with saliva. Touch the tip of your wet tongue to the free ends of the two wires.\n\nYou should be able to feel a slight tingle on the tip of your tongue and taste something metallic.\n\n\n\nwhat you will discover\n\nThe lemon battery is called a voltaic battery, which changes chemical energy into electrical energy.\n\nThe battery is made up of two different metals (the steel paper clip and the copper wire). These are called electrodes, which are the parts of a battery where electric current enters or leaves the battery. The electrodes are placed in a liquid containing an electrolyte, which is a solution that can conduct electricity.\n\nIn a solution of water and an electrolyte, like the acid in the lemon, an excess of electrons collects on one end of the electrodes. At the same time, electrons are lost from the other electrode.\n\nTouching the electrodes to your tongue closes the circuit and allows an small electric current to flow. A single lemon produces about 7/10 of a volt of electricity. If you connected two lemons together, you can power an inexpensive digital watch (uses about 1.5 volts). (Use a length of thin, flexible wire to connect the silver wire of one lemon to the copper wire of the other lemon. Then attach thin wires from the other two wires in the lemons to where a battery's positive and negative poles connect to power the watch.)\n\nThe tingle felt in your tongue and the metallic taste is due to the movement of electrons through the saliva on your tongue.\n\n\n--well, i just searched for it. hope i helped in a way ^_^\n\n-paul
464475
Don't try this one yourself! Use a pet rat or something!\n...\nActually, don't! Or i'll get hunted by Animal Rights Activists!!\n\nAll you need is a battery, two wires and a large capacitor.\nCharge the capacitor by connecting the battery across it with the two wires.\nThen disconnect the wires.\nThe capacitor has now been charged - if you put your hands across the terminals, you'll get a nasty shock.
203972
I've done some research on this because I seem to remember my teacher talking in school about how they can make batteries with graphite (pencil lead) and vinegar that put out more energy and are more environmentally safe than regular batteries. I'm not sure how this happens but I know that you can take vinegar and pour some into powdered graphite, rub it into a block of wood, and when the vinegar dries the wood will be extra strong because the vinegar disolves the graphite long enough for it to bind to the wood. I can't find any research or projects to back this up but that is what I remember on the subject. Perhaps you could split a pencil and drop the lead in for a few days and see? Maybe use two and a nine volt battery and see what a current does to affect the chemical process...I wish I could help you more.
430405
A better method is an electric fencer, which can be battery operated. If it can keep cows from leaving their coral it should provide enough juice to electrify catfish.\n\nCheck out the following link:
424418
in Solar Battery!!\n\nmuahahahahahahaha
263714
The best project will be one that has some interest to the 8th grader. So my granddaughter likes animals. But my youngest boy likes photography. So a pinhole camera would bore my granddaughter but would have caught the interest of my son.\n\nThat being said... Here's an easy one. Go to a store and find some cheap analog clocks (clocks with hands) that run on a single AA battery. Then go to Radio Shack and get some battery holders and some "aligator clip leads" -- short wires with clips on either side. And get a bunch of different brand batteries of different sizes (if you are trying to get by simply, use only AA batteries and then you just need the clocks and the batteries).\n\nTake off the battery covers and hook up the battery holders to the clocks with the clipleads (unless you are only using AA batteries). Then put batteries in and see how long it takes for the clocks to run down. This may take a long time. If you are short on time, try this. Get a flashlight bulb at radio shack and put it across the battery with the clock. So this way the battery is running the clock and the flashlight bulb at the same time. Note the time on the the clock and check it every day to see when the clock stops. You can graph the results easily.\n\nQuestions (form a hypothesis and answer one or more of these):\nWhat lasts longer, a AA, a C, or a D battery?\nWhat brand of battery lasts longer?\nWhat lasts longer, a standard carbon-zinc battery or an alkaline battery? What is the cost difference per unit? Per run time?\n\nA little research on the internet about how batteries are built, and the different technologies (carbon-zinc, alkaline, nicad, NiMh, lithium, lead-acid) and you have a great project.
438682
sure. go to a science store or look up schematics on the web.
959970
don't know alll the answer (using a desktop ) \nright click desktop and go properties > screen saver tab then click power options \nthe infomation is here you should be able to place a battery icon in the system tray. which you can highlight and it will give you power left in battery in %
563439
Build a solar cell from a couple of thin sheets of copper and some salt water.  It requires a heat source, but with parental supervision it can be done by a 4th grader.  Easy!\n\n(see links below for how it's done)
503737
You could start with a junked fan, like a window fan. The bigger the better. If you can remove the blade from the shaft, you could use a similar shaft with a pulley on it to transfer the mechanical energy to a place where you can use it. You may have to bend the blades to get the best output.\nIf you build your own, you can make it much larger. I'd use plywood to make flat blades; not as efficient but a lot easier to make than curved ones. Or you could go Dutch style and make the blades latticed with a fabric cover, maybe nylon or dacron.
789204
Give the site below a try! Good luck.\n\n<This is for fun only. If you are actually trying to do this to heat your house or use for power, I don't think you can do that. You would need commercially made cells, but you could set up the system yourself.>