Batteries are a store of electricity. You can use them to power things that require electricity. Having many batteries does not mean you generated the electricity, nor does it even imply that you acquired the batteries using fair means. Wealth **is** a store of labor. You can use it to compel others to do labor for you, or to give you things that required labor to acquire. Having a lot of wealth does not mean you did the labor required to earn it, nor does it even imply you acquired that wealth using fair means.