For you math geniuses out there: If gas weighs 6 pounds per gallon, how much does a

[Wonder Why]

KW weigh in my electric car? I'm afraid I'm overloading my EV with the stuff in the trunk so I figure I'd reduce the KW of charge to carry more.

One nice thing about an EV - my dealer gives free oil changes for the life of the vehicle.

Every time my vehicle runs low on fuel, I go to a charging station. Since everyone is adding a 3% fee for charging, does anyone know a cashing station I could use instead? Is that what an ATM machine is for? Where do they hide the cable to connect to my car?

Even years back, people complained that gas stations overcharge for gasoline because the gas in the hose goes back into the tank even if it has already passed the meter. Is that the same with EVs? Is there any way to get those extra amps still in the line to continue to flow into my car?

[Gore1FL]

1. A charged battery does, in fact, weigh more than a discharged battery

I suspect the difference is less than an ounce, but E=mc^2 is a thing.

[mahatmakanejeeves]

3. In a charged battery, the electrolyte consists of concentrated sulphuric acid.

As the battery discharges, the sulphuric acid breaks down into positively and negatively charged ions that are deposited on the electrodes. Mass does not into and out of the battery during the charging and discharging cycles. I mean, where is it going?

https://academy.gs-yuasa.eu/wp-content/uploads/2019/05/Lead-Acid-Battery-Operation.pdf

Battery discharge process

Negative plate
The discharge process begins as soon as an electrical load is applied to the battery. This takes the form of a chemical reaction between the negative plate and the sulphuric acid in the electrolyte solution. The sulphuric acid begins to break down into positively charged hydrogen ions (H+) which move to the positive plate and negatively charged sulphate ions (2-) which move to the neutral porous lead atom on the negative plate. The porous lead atom on the negative plate becomes ionised and negatively charged as the sulphate ion attempts to bond with it. To complete the bonding process and achieve a neutral charge state the lead atom must become positively charged. It therefore releases 2 negatively charged electrons. These 2 free electrons can now flow through the electrical circuit through the applied load and on into the positive plate.

Positive plate
The two negatively charged electrons from the negative plate arrive at the positive plate and bond with the
positively charged lead ion (4+) in the neutral lead dioxide molecule. This causes the charge of the lead ion to change from (4+) to (2+) as there are now only two more protons than electrons in the lead ion, altering what is known as the oxidisation state of the lead ion. Negatively charged sulphate ions (2-) produced from the breakdown of the sulphuric acid bond with the positively charged lead ion (2+) on the surface of the plate creating a neutral molecule of lead sulphate and releasing negatively charged oxygen ions into the electrolyte. The two hydrogen ions (H+) approach and bond with the negatively charged oxygen ion (2-) creating a neutral molecule of water (H2O). The battery is now discharged.

Further, there are not nuclear reactions going on inside the battery. You are not changing one element or isotope into another. Just look at the energy equivalent of one gram of mass.

https://www.quora.com/What-is-the-energy-equivalent-to-the-mass-of-1gm

So 1 g of matter is about 90 trillion joules of energy. According to this page it’s estimated that humans generated (& used) about 5.67e20 joules in 2013, which would be about 6.3 million grams worth (which is 6,300 kilograms).

More here: https://www.reddit.com/r/AskPhysics/comments/op5kxm/eli5_in_what_sense_does_1_gram_of_mass_relate_to/

[SWBTATTReg]

2. You know, I got a kick out of your question but I daresay that there will be some twitchy fingers on

people's calculators trying to figure out an answer to your questions. Maybe someone has some answers already?

Let us know if someone passes along something to you!

[Wonder Why]

8. Well, thank you for recognizing that this is the humor forum. I was beginning to think I was the only one.

[mahatmakanejeeves]

4. A kilowatt is a unit of power. You want a kilowatt-hour, which is a unit of energy.

So look at battery weight. How much does a battery weigh vs. how many kilowatt-hours of energy can it source at a usable voltage? You can’t really count the kilowatt-hours down to zero, as once you drop below the system voltage, the battery can’t source any more useful current.

[Wonder Why]

6. You do realize this is the humor forum, don't you? The WEIGHT of a KW or a KWH vs the WEIGHT of gasoline?

Have you ever weighed a KW or a KWH? Ever weigh a battery full vs empty? Pffft!

[eppur_se_muova]

5. Most batteries nowadays are sealed systems. Change in weight should be undetectable.

The only exception I can think of is the zinc-air battery, which absorbs air as it discharges, and thus gains weight.
https://en.wikipedia.org/wiki/Metal%E2%80%93air_electrochemical_cell

[Wonder Why]

7. Exactly! It's the HUMOR forum, not the science forum.

[eppur_se_muova]

9. I did not even notice that. Well, you know more now.

[Wonder Why]

10. By the way folks, a full EV 75 KW battery weighs about 3 micrograms more than an empty one.

Even a full EV battery pack — the largest, most energy-dense consumer battery most people will ever interact with — gains only a few millionths of a gram in mass. That’s still lighter than a speck of dust, and it has zero effect on a car’s weight, range calculations, or handling.

https://www.tycorunenergy.com/do-batteries-weigh-more-when-charged/]

[chowmama]

11. I thought ' a pint's a pound, the world around'.

KW - I'm not sure.