Battery potential energy versus mass

In summary, the conversation discusses the relationship between energy extracted from a battery and the corresponding reduction in mass, and whether it is possible to measure this difference with precise instrumentation. It is stated that there will be a decrease in mass due to the discharge of the battery, but it may be too small to measure accurately. The example of a car lead battery and the precision needed to measure the difference in mass is also mentioned.
  • #1
rcgldr
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I'm asking this question on behalf of another person who doesn't know english well.

What he wants to know is the relationship between energy extracted from a battery and the corresponding reduction in mass of the battery, and if it would be possible to measure the difference with some type of precise instrumentation rather than than it being an abstract calculation.

Asume that all energy outputs, including electrical and heat related losses are considered in the relationship between reduction of potential energy and reduction of mass.
 
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  • #2
Yes, there should be a diminuation in mass of the battery when it discharges, according to relativity. As to be able to measure this, I don't think this is going to be possible, as the change is too small.

120 Ahr at 12V (a serious car lead battery) corresponds to about 5 MJ, which corresponds (mc2) to ~60 nanogram.
I don't think you can see a difference of 60 nanogram on the weight of a car battery of say, 20 kg. You'd need a precision of about 12 digits to start seeing the difference.
 

FAQ: Battery potential energy versus mass

What is battery potential energy?

Battery potential energy is the amount of energy that a battery can store and release through a chemical reaction. It is measured in joules (J) or watt-hours (Wh) and is dependent on the type and size of the battery.

How is battery potential energy related to mass?

The potential energy of a battery is directly proportional to its mass. This means that the larger the mass of the battery, the greater its potential energy and the longer it can power a device.

Can battery potential energy be increased by adding more mass?

Yes, adding more mass to a battery can increase its potential energy. This is because the amount of energy a battery can store is dependent on the amount of reactants present in the battery, which increases with more mass.

Does the type of battery affect its potential energy?

Yes, the type of battery does affect its potential energy. Different types of batteries have different chemical compositions, which can result in varying potential energy levels. For example, lithium-ion batteries have a higher potential energy than alkaline batteries.

Can the potential energy of a battery be converted into other forms of energy?

Yes, the potential energy stored in a battery can be converted into other forms of energy, such as electrical energy. This occurs when the battery is connected to a circuit and the chemical reaction inside the battery produces an electric current.

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