Ampere hour: Difference between revisions
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<onlyinclude>An '''ampere hour''' (abbreviated A<math>\cdot</math>h or amp hr) is a [[units|unit]] of electric [[charge]], usually used for [[battery|batteries]]. This unit combines the amount of [[current]] with how long that current can be sustained until the battery completely discharges.</onlyinclude> Large batteries have several ampere hours but cell phones and other small devices have batteries with a total charge measured in milliampere hours. | <onlyinclude>An '''ampere hour''' (abbreviated A<math>\cdot</math>h or amp hr) is a [[units|unit]] of electric [[charge]], usually used for [[battery|batteries]]. This unit combines the amount of [[current]] with how long that current can be sustained until the battery completely discharges.</onlyinclude><ref name=B>R.T. Paynter, “Basic Electric Components and Meters,” in ''Introduction to Electricity'', 1rst ed. NJ: Prentice-Hall, 2011, ch. 3, sec. 3.4, pp. 90.</ref> Large batteries have several ampere hours but cell phones and other small devices have batteries with a total charge measured in milliampere hours. This measured quantity is called [[battery capacity]].<ref name=B/> | ||
The number of amp-hours in a battery is found by multiplying the amount of current (in [[ampere]]s) by the time (in [[hour]]s) a given current could flow before the battery runs out. This calculation gives the total amount of charge transferred. This unit is useful since a battery will be able to supply current for a longer period of time, than say a [[capacitor]]. [[Chemical reaction]]s inside the battery are limited by the amount of material that can be eaten away, and how quickly, this means that to test the ampere hours of a battery one should use a low current relative to the battery's peak current capability. | The number of amp-hours in a battery is found by multiplying the amount of current (in [[ampere]]s) by the time (in [[hour]]s) a given current could flow before the battery runs out. This calculation gives the total amount of charge transferred. This unit is useful since a battery will be able to supply current for a longer period of time, than say a [[capacitor]]. [[Chemical reaction]]s inside the battery are limited by the amount of material that can be eaten away, and how quickly, this means that to test the ampere hours of a battery one should use a low current relative to the battery's peak current capability. | ||
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To learn more about the ampere hour please see Dr. Rowlett's [http://www.unc.edu/~rowlett/units/dictA.html#ampere dictionary of units]. | To learn more about the ampere hour please see Dr. Rowlett's [http://www.unc.edu/~rowlett/units/dictA.html#ampere dictionary of units]. | ||
== For Further Reading == | |||
For further information please see the related pages below: | |||
*[[Battery]] | |||
*[[Electric charge]] | |||
*[[Fuel cell]] | |||
*[[Capacitor]] | |||
*[[Electric current]] | |||
* Or explore a [[Special:Random| random page!]] | |||
==References== | |||
{{Reflist}} | |||
[[Category:Uploaded]] | [[Category:Uploaded]] | ||
Revision as of 21:04, 9 May 2018
An ampere hour (abbreviated Ah or amp hr) is a unit of electric charge, usually used for batteries. This unit combines the amount of current with how long that current can be sustained until the battery completely discharges.[1] Large batteries have several ampere hours but cell phones and other small devices have batteries with a total charge measured in milliampere hours. This measured quantity is called battery capacity.[1]
The number of amp-hours in a battery is found by multiplying the amount of current (in amperes) by the time (in hours) a given current could flow before the battery runs out. This calculation gives the total amount of charge transferred. This unit is useful since a battery will be able to supply current for a longer period of time, than say a capacitor. Chemical reactions inside the battery are limited by the amount of material that can be eaten away, and how quickly, this means that to test the ampere hours of a battery one should use a low current relative to the battery's peak current capability.
1 Ah = 3,600 Coulombs
Often the amp hour is written on the side of a battery, which has a voltage (often 1.5 V). An ampere hour at 1 volt is a unit of energy, specifically the watt-hour (1/1000th of a kWh).
To learn more about the ampere hour please see Dr. Rowlett's dictionary of units.
For Further Reading
For further information please see the related pages below:
- Battery
- Electric charge
- Fuel cell
- Capacitor
- Electric current
- Or explore a random page!