‘Dr. Stone’ episode 21 air date, spoilers: Senku builds batteries to store energy for making cellphones in ‘Spartan Crafts Club’

“Dr. Stone” episode 21 will pick up from the time when craftsman grandpa Kaseki and Chrome surprised everyone with their waterwheel creation. They spent days to built it, but while Senku was impressed, he said that they have more things to do before they can make the cellphone.

As posted on Dr. Stone Fandom, “Dr. Stone” episode 21 has been titled “Spartan Crafts Club,” and judging by the title, it appears that Senku was not kidding when he said that they still have a lot to do. It sounds like, despite shifting from manual to hydropower energy to hasten their work and make it easier, they will still be doing their tasks in a rigorous way, thus the word “spartan” in the title.

What is the next invention?

“Dr. Stone” episode 21 will still be about Senku and the villagers’ goal to make a cellphone for easy communication that will help with defeating Tsukasa. They previously invented the machine that will produce gold threads that will become conductors later. The machine also makes the best cotton candy, so it was a great item.

Now that they have the waterwheel to power the machine that will make the gold threads, work is easier. They also made batteries that can store energy, and it was successful.

Senku proceeded to lead everyone to make an air-blowing machine for building fires, and they used this to make glass. It turned out that Senku wants to make a lightbulb, and they made it.

To test out their new invention, they filled a tree with lightbulbs and used the battery to light it up. Coincidentally, it is Christmas, and they just lit up their Christmas tree in “Dr. Stone” episode 21. In any case, there is a glitch with the bulb as the filament always breaks, but Chrome’s new materials might help make the perfect lightbulb next time.

When is it airing?

“Dr. Stone” episode 21 was released on Nov. 21, but this was the Japanese version. Game Revolution noted that the English dubbed edition would be coming out via Funimation on Dec. 6, and it will also be aired on Toonami on Jan. 11, 2020.