• SomeoneSomewhere@lemmy.nz
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    8 months ago

    If you genuinely use the magnets as a battery, they just don’t store enough energy. Wikipedia lists Neodymium magnets as storing about 512kJ/m^3, and lead-acid batteries as about the same amount but per litre - so a thousand times more dense.

    Remember that energy removed must equal energy added, so you need to find a way to pump those megawatt-hours into the battery.

    In addition, energy storage mechanisms generally have to release that same amount of energy when destroyed. A fully charged lithium battery makes a serious fire, especially if it’s a big one. A big tank of petrol makes a big fireball, when allowed to mix with air. A spring or a magnet mostly just goes ‘bang’.