In Ant-Man & The Wasp (2018), Hank Pym's lab is powered by enlarged Duracell

Correct me if I'm wrong

But isn't the theory that he shrinks or expands the space between molecules or something?

So he'd be powering his entire base off of the power of a normal Duracell battery

that's the "theory", but if that were true, pym wouldn't have been able to carry that tank in his pocket in the first movie. and if he could, ant man would have no power to punch while shrunk. It's awfully convenient.

So I suppose when Antman grows, the glucose in his blood grows too and he can have energy?

I don't know if the glocose grows, but the amount of oxygen he needs in Giant-Man form is why he can't hold it for very long, and the time he can hold it gets shorter the larger he grows.