Assuming Dr. Stone is some kind of MacGyver regen:
Two obvious approaches to me that I’ll run through in high level: build a wind/watermill generators or potato/lemon batteries
First thing you’ll need to figure out for both is how to make some wire. That’s going to require finding some metal ore and a hot furnace, and creating a few tools out of stone to work with it.
The biggest difficulty with the former two is going to be finding some ferrous metal to turn into magnets. You can make a magnet without electricity by smashing the shit out of some iron as it’s aligned with the earth’s magnetic field, and it’ll become a weak magnet. From there with enough wire, you can build a generator. With the sails of the mill, you can build that out of wood and foliage.
For potato or lemon batteries, you’re going to need a shitload, as they give you about a volt and a pretty tiny current, but theoretically you could figure something out that way with enough. I imagine some things may want to eat your batteries though
how to make some wire. […] finding some ferrous metal to turn into magnets.
These two ingredients put our 120v dynamo really far up the tech tree from “make fire.” Our intrepid time travelers are going to spend years trying to not be velocaraptor food and foraging for a meal themselves, all while making stupendous amounts of charcoal and prospecting for ore.
Dr. Stone is an anime about humanity being thrust back into the neolithic and a genius kid developing a nation of science to save the world by speedrunning the technology tree.
Your lemon batteries will be DC tho. I think step one would be to start carefully dismantling the Time Machine to see what it really needs and what parts might be unneeded and reusable in a generator.
Assuming Dr. Stone is some kind of MacGyver regen:
Two obvious approaches to me that I’ll run through in high level: build a wind/watermill generators or potato/lemon batteries
First thing you’ll need to figure out for both is how to make some wire. That’s going to require finding some metal ore and a hot furnace, and creating a few tools out of stone to work with it.
The biggest difficulty with the former two is going to be finding some ferrous metal to turn into magnets. You can make a magnet without electricity by smashing the shit out of some iron as it’s aligned with the earth’s magnetic field, and it’ll become a weak magnet. From there with enough wire, you can build a generator. With the sails of the mill, you can build that out of wood and foliage.
For potato or lemon batteries, you’re going to need a shitload, as they give you about a volt and a pretty tiny current, but theoretically you could figure something out that way with enough. I imagine some things may want to eat your batteries though
These two ingredients put our 120v dynamo really far up the tech tree from “make fire.” Our intrepid time travelers are going to spend years trying to not be velocaraptor food and foraging for a meal themselves, all while making stupendous amounts of charcoal and prospecting for ore.
Dr. Stone is an anime about humanity being thrust back into the neolithic and a genius kid developing a nation of science to save the world by speedrunning the technology tree.
spoilers
They do exactly what what you mention!
https://www.imdb.com/title/tt9679542/

But where in the backstory did every girl on the planet get gene-spliced with a hammerhead shark?
Your lemon batteries will be DC tho. I think step one would be to start carefully dismantling the Time Machine to see what it really needs and what parts might be unneeded and reusable in a generator.
Step 1 then: make tools
don’t forget there are dinosaurs. use them for work, probably easier than a water wheel.
What about making a capacitor and charging it with a lightning rod?
Fire