Does the emf of a battery remain its specified value for a long time?

In summary, a battery's emf value can decrease over time as the chemicals within the battery run out, leading to a decrease in energy. This is known as discharging, while the process of increasing the emf value from 0 to its specified value is called charging.
  • #1
sArGe99
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Does the emf of a battery remain its specified value for a long time. It is under discharging when connected to the external resistor, so shouldn't its emf value continuously decrease in that case?

A battery's emf value increases from 0(completely discharged state) to the specified value. Isn't this what's called charging?
 
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  • #2
sArGe99 said:
Does the emf of a battery remain its specified value for a long time. It is under discharging when connected to the external resistor, so shouldn't its emf value continuously decrease in that case?

A battery's emf value increases from 0(completely discharged state) to the specified value. Isn't this what's called charging?

Well the chemicals within the battery can run out, that is why the emf decreases over time. Which is why batteries run out of energy.
 
  • #3


I can confirm that the emf (electromotive force) of a battery does not remain at its specified value for a long time. The emf value of a battery is determined by its chemical composition and will gradually decrease over time as the battery is used and discharged. This process is known as self-discharge.

When a battery is connected to an external resistor, it will continue to discharge and its emf value will decrease. This is because the battery is converting its stored chemical energy into electrical energy to power the external circuit. The rate at which the emf decreases will depend on the type and condition of the battery, as well as the external load.

The process of charging a battery involves applying an external electrical current to the battery, which causes a chemical reaction that restores the battery's chemical energy and increases its emf value. This is why a battery's emf value increases from 0 (completely discharged state) to its specified value during the charging process.

It is important to note that even when a battery is not in use, it will still undergo self-discharge and its emf value will gradually decrease. This is why it is recommended to store batteries in a cool and dry place to minimize self-discharge and preserve their emf values for a longer period of time.

In summary, a battery's emf value will decrease over time as it is used and discharged, and will need to be recharged to restore its specified value.
 

1. Does the emf of a battery decrease over time?

Yes, the emf (electromotive force) of a battery does decrease over time, as it is affected by factors such as internal resistance and chemical reactions within the battery. This decrease is known as battery degradation.

2. How long does a battery's emf stay at its specified value?

The length of time that a battery's emf stays at its specified value depends on factors such as its type, usage, and storage conditions. In general, a battery's emf can remain close to its specified value for a few months to a few years.

3. What causes a battery's emf to decrease?

A battery's emf can decrease due to a variety of factors, including internal resistance, chemical reactions, and age. As a battery is used and recharged, its internal components can degrade, leading to a decrease in emf.

4. Can a battery's emf be restored to its specified value?

In some cases, a battery's emf can be restored to its specified value through techniques such as equalization charging or replacing the battery's internal components. However, this may not always be possible, and the emf may continue to decrease over time.

5. How can I prolong the emf of a battery?

To prolong the emf of a battery, it is important to use and store it properly. This includes avoiding extreme temperatures, fully charging and discharging the battery regularly, and using the correct charger and charging method for the battery type. Regular maintenance and replacement of old batteries can also help prolong their emf.

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