Batteries are made up of a series of cells that have chemical reactions in them producing electricity. For typical alkaline cells, the maximum you can get out of each reaction is 1.5 volts, so to make a 6 volt battery you need to connect 4 of them together in series, or to make a 9 volt battery you need 6, and so on. These cells can be large or small depending on how much power you need, so you can get some very small 12 volt batteries but they wont last very long.
If you are referring to 12 volt car batteries they need to produce a very large amount of power to start an engine, and they have a slightly different type of chemical reaction (lead/acid). Each cell still produces I think 1.5 volts, so there would be 8 large cells in each battery if that is the case. The small 9 volt batteries are typically used for small devices that need the voltage but use very little power, for example smoke alarms.
Hope this helps.
2006-08-31 01:33:25
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answer #1
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answered by PolarCeltic 4
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Twelve volt car batteries are much larger than nine volt accessory batteries because the size is related to the required current, not the voltage.
To get a clearer picture of the relationship between voltage and current. Current is a measure of what flows in the circuit and voltage is a measure of how strong it can be pushed in the circuit. If you imagine a hammer and a nail. Voltage is the size of the hammer and current is the size of the nail.
It does have to do with the chemical makeup. Chemical reactions cause the electricity in both batteries, but since a car takes much more current to start and runs much more accessories, it is bigger because it runs more current to power things. Mostly it is the starting of the car.
Square shaped 9v batteries only run a remote control or small radio. Even larger boom boxes take several D batteries.
AAA, AA, C and D batteries are all the same voltage 1.5V. They all have different current demands. The more they do the larger they are, but it isn't because of the voltage. It's the current demanded by the accessory.
If you ever take a small rectangular 9v battery apart, you see the 1.5 tubular AAA type cell soldered together in series inside!
2006-08-31 11:13:09
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answer #2
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answered by Ken C. 6
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The prior answer has one thing wrong. A lead-acid cell is 2V, not 1.5V, and there are 6 cells in a 12V car battery. Every chemical type has a voltage associated with it (although the voltage changes with the remaining charge). A 12V car battery is significantly bigger than a 9V battery because it has much more charge and current capability. You can put 8 AA batteries in series to get 12V, but you'll never start your car with it.
Besides voltage, every battery has a charge capacity (measured in ampere-hours or mAh, etc) and a maximum current capacity (in amperes). The latter is more fuzzy because the more current you draw the lower the voltage will be, and that may or may not be a problem. Starting a car will drop the voltage significantly below 12V, but that isn't a problem. You couldn't use that battery to drive a 12V load that required that current continuously.
2006-08-31 05:27:08
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answer #3
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answered by An electrical engineer 5
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yes, and the container too, if it is made in the same size, it will have shorter span of live, imagine a batteries for a hand watch
2006-08-30 19:35:19
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answer #4
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answered by Henry W 7
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