Does charging up a battery ultimately increase its overall weight?
In: 12
Yes, but not in any meaningful way. The difference in weight fully charged car battery is about the same as the mass of rubber that your tires lose when you accelerate from a stop.
It only increases in mass (and thus weight, all else being equal) thank’s to relativity. Something with more energy is going to have more mass. In the same way that things going faster have more mass. This is simply a non-factor in day-to-day life but it’s *technically* true.
Technically, yes as E=mc^2. Last I saw a measurement, 360 megajoules of potential energy weighs about
t 0.004 g. It would take 250 car batteries to store 1g of energy.
Yes, but it’s so incredibly tiny, because a small amount of mass contains a massive amount of energy, as per E= MC2
Conversely, a small amount of energy, such as that stored in a battery, converts to a very very very very very tiny amount of mass.
As others have said, yes.
Though, I do want to make clear that it is not be for the reason you might be thinking. You didn’t say it in your question, but if your intuition of electricity and how that relates to the weight of the battery happens to go something like this:
1. Electricity is moving electrons.
3. Electrons have weight.
2. Batteries are electron storage tanks.
4. A charged battery has more electrons in it than a dead one.
5. Therefore, a charged battery weighs more than a dead on.
…then, no, that isn’t the reason why. That’s not really how electricity or batteries work.
By and large, the battery has the same amount of electrons in it no matter what state of charge it’s in. It’s not about how many are in it, but how they’re arranged.
When a battery is charged, certain chemical bonds are formed that wouldn’t form under normal circumstances. These bonds store the energy used to charge the battery. You can think of it as like countless tiny little mousetraps being set. Energy is being used to counteract the spring mechanism holding the mousetrap closed, and then they’re latched into that open position, storing that energy. Later, when discharging the battery, the energy that the battery supplies to electrical components such as light bulbs comes from these chemical bonds snapping apart. As if all those tiny imaginary mousetraps were snapping closed, releasing their stored energy.
The battery is heavier because all that pent-up energy in the chemical bonds, on its own, has “”weight””. (Technically *mass*, which not the same thing as weight, but in this specific context that’s not extremely important.) It’s an imperceptibly tiny amount, but nonzero. It would hardly be measurable with even some of science’s most sensitive equipment. But it’s *calculatable*. It’s real. Just ludicrously small.
No. The act of charging/discharging the battery are moving the electron from one side to another side. In the end, the amount of electron will stay the same.
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