Do full batteries weigh more?

[EngenZerO]

uhm, no

 

[RelaxTheMind]

yes... they do actually... all chemicals break down. Using the battery itself hurries this process.

weigh a regular old AA battery. Use it up and then wait a week or so and weigh it again. You will see quite a difference.

ever notice a car battery's cells somewhat lower than when initially bought?

 

[MrDudeMan]

Originally posted by: Peetoeng
If my calculation was correct, for a battery with a power rating of 100 amp-hr, the electrons would weigh about 2 ug (micrograms)

your calculations are most certainly not correct. electron mass is .511MeV, or 10^-31kg.

there is no way they gain mass. that would mean they have reactive elements that store more charge via the network connection than they output, which is absurd.

the power from a battery doesnt come from changing energy levels. it comes from the differences in potential of whichever band gaps are occupied/unoccupied. when people say the internal resistance is too high (the common thing to say when a battery isnt delivering the specificed voltage), really what they are saying is the potential from one side of the battery to the other has a diminished electromagnetic field and the probability of an electron to jump sides, or jump out of a shell to cause a pair, thus creating a current, is less.

gain mass? no. when the electrons recombine with a hole after being pulled out into the conduction band, they settle into a lower energy state, but not in a lower energy level. there are 10^20 or more energy levels in each band gap, so that party really doesnt matter. only 1 electron in each level can spin a certain way, even if the wave quantum number is the same. nevermind actually...no one is even going to read this.

 

[Rock Hydra]

Originally posted by: Heisenberg
In terms of anything you could practically measure, no.

Well technically yes, but practically. I would say no, since there is no practical way to determine that. don't tink electrons are even counted in atomic mass. i'm kinda rusty on my physics though.

 

[miniMUNCH]

Originally posted by: FelixDeKat
I cant stand heavy batteries, they are so hard to change. The one in my Mercedes was 75lbs!!!!!! :|

Oh!! Your Mercedes battery is so heavy...please hold on while I strike up the violins.

 

[Evadman]

a charged battery would have more mass (don't confuse mass and weight) but not because of electrons. When a battery is discharged, the electons move from one plate on the battery to the other (though the circuit) so the number iof electrons is equal.

However, by charging the battery, energy is being imparted into the battery (obviously). This energy raises the mass of the battery by E=MC^2. Though the mass increase would be nearly infintessimal.

Concider this: The total amount of enery contained in a paperclip (1 gram) is roughly equivelent to 18 kilotons of TNT, or about the size of the explosion from Little Boy (Hiroshima). How much energy do you think you are imparting by charging that battery? Not a whole not.

Heck, a decent size house (at 60 tons) if converted into energy would release the energy of over 1 trillion tons of TNT, enough to split the earth in 2. Excellent!

 

[kirkaptain]

No.

 

[myusername]

Originally posted by: EvadmanHeck, a decent size house (at 60 tons) if converted into energy would release the energy of over 1 trillion tons of TNT, enough to split the earth in 2. Excellent!

Sir, I'm afraid we have to seize your house on the grounds that it's a WMD.

 

[Pepsei]

yes

 

[Keego]

no. electricity is fake and we're all being duped!

 

[Colt45]

not unless its nuclear, no.

 

[thescreensavers]

Originally posted by: miniMUNCH

Originally posted by: FelixDeKat
I cant stand heavy batteries, they are so hard to change. The one in my Mercedes was 75lbs!!!!!! :|

Oh!! Your Mercedes battery is so heavy...please hold on while I strike up the violins.

This made me laugh

 

[PowerMacG5]

I think the correct answer is it depends on the type of battery.

For a primary cell, I believe it will be. For example, the chemical reaction taking place in an alkaline batter is:

Zn + 2 MnO2 + H20 --> Zn(OH)2 + Mn2O3

In an alkaline battery (primary cell) the electrolyte (H20) is consumed in the reaction, therefore the overall mass is reduced.

For a rechargeable, I don't believe so. For example, the chemical reaction taking place in a NiCad battery is:

2 NiO(OH) + Cd + 2 H2O <--> 2 Ni(OH)2 + Cd(OH)2

The direction of the arrow is dependent on whether it is being charged or discharged (left to right discharging, right to left charging). The electrolyte (KOH) inside is not consumed in any way, therefore the mass is not reduced.

 

[iamaelephant]

Originally posted by: Colt45
not unless its nuclear, no.

Arg. e=MC^2 is not limited to nuclear reactions. If you heat something it's weight increases by a small amount. Any energy added to a system will increase the total mass of the system.

 

[mercanucaribe]

Originally posted by: Evadman
a charged battery would have more mass (don't confuse mass and weight) but not because of electrons. When a battery is discharged, the electons move from one plate on the battery to the other (though the circuit) so the number iof electrons is equal.

However, by charging the battery, energy is being imparted into the battery (obviously). This energy raises the mass of the battery by E=MC^2. Though the mass increase would be nearly infintessimal.

Concider this: The total amount of enery contained in a paperclip (1 gram) is roughly equivelent to 18 kilotons of TNT, or about the size of the explosion from Little Boy (Hiroshima). How much energy do you think you are imparting by charging that battery? Not a whole not.

Heck, a decent size house (at 60 tons) if converted into energy would release the energy of over 1 trillion tons of TNT, enough to split the earth in 2. Excellent!

I don't think that's true. A battery doesn't convert energy to matter or vice versa. Based on what you're saying, moving a rock up a hill so it has higher potential energy increases its mass, when we know the amount of matter remains identical.

 

[Chiropteran]

If your batteries feel a little light you might need to refill the fluid.

 

[SVT Cobra]

Originally posted by: Evadman
a charged battery would have more mass (don't confuse mass and weight) but not because of electrons. When a battery is discharged, the electons move from one plate on the battery to the other (though the circuit) so the number iof electrons is equal.

However, by charging the battery, energy is being imparted into the battery (obviously). This energy raises the mass of the battery by E=MC^2. Though the mass increase would be nearly infintessimal.

Concider this: The total amount of enery contained in a paperclip (1 gram) is roughly equivelent to 18 kilotons of TNT, or about the size of the explosion from Little Boy (Hiroshima). How much energy do :thumbsup:you think you are imparting by charging that battery? Not a whole not.

Heck, a decent size house (at 60 tons) if converted into energy would release the energy of over 1 trillion tons of TNT, enough to split the earth in 2. Excellent!

nice post! I enjoyed reading that! :thumbsup: