• ki9@lemmy.gf4.pw
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    6 hours ago

    I thought about building a gravity battery in my yard.

    The math is E = mgh. Not complicated. I think the conclusion was that to charge my cell phone from zero to 100% I would have to lower 1, 000 pounds from a height of 100 feet. Had to make some assumptions about my phone battery capacity… But still… Wildly inefficient.

    That was before losses and this video says the building is 80% efficiency.

    So whenever I see one of these grav batts actually being built, I wonder if they checked? I mean, it has some capacity but will it ever be worth the construction costs?