I generally make batteries at the oil refinery and then run those onto the bus. If the refinery is making sulfuric acid, you need iron, so all you need to make batteries there is to change a full iron ...

I’ve done full blue belt of blue circuits. It takes a lot of infrastructure. 24 belts of greens (fed by 16 belts of copper and iron), 4 (I think) belts of reds. Lots of plastic to feed the red plant.