3 ms·

Doesn't a full battery carry more electrons and is therefore heavier?

• jbotz 6y ago
  No. Aside from the fact that the weight of the electrons, although not zero, is negligible, they also don't get "lost" in the process... they just get moved around, in the case of battery power literally from one end of the batery to the other. Combustible fuel in contrast, gets turned into gases (CO2 and H2O) which are blown out the exhaust and thus lost.
  • arcticbull 6y ago
    Yes. A small amount. A 100kWh Tesla battery has 3.6e+8 Joules of energy. E = mc^2 tells us that the mass of the stored energy is 4e-9 grams, so 4 nanograms.
    • Dylan16807 6y ago
      No. The number of electrons does not change. Instead, the different configuration causes a slight fluctuation in the mass of the atoms.
      • arcticbull 6y ago
        I wasn't referring to parent's suggestion that the number of electrons changed, of course, you're right, it doesn't. Just that the weight does in fact change.
        • Dylan16807 6y ago
          > I wasn't referring to parent's suggestion that the number of electrons changed So help me out here, am I missing something? It's a two part question, and only half a part is actually true. "more electrons" is false, and "therefore" is false, but "heavier" is correct. In that situation, I think an unqualified "Yes." is extremely misleading. So I wrote "No." as the lead-in for my comment. Is that super rude? Am I completely wrong, and an unqualified "Yes." is actually appropriate here? Is there some other reason for me to get multiple downvotes for my post? If I'm doing something wrong, I'd like to correct it for the future.
• jcims 6y ago
  Think of it like a mousetrap. Two energy states, same mass.
• m-p-3 6y ago
  Yes, as it follows E = mc², but it would be so incredibly tiny that a speck of dust would weight more than the difference it would make between charged and discharged.
• deleted 6y ago
  [deleted]