Ah, the power cell, a remarkable feat of standardization. Everything from the small scavenging tools to the largest AADZ skyscraping mega-plex on the Mars surface takes a form of these power cells. They aren't the most complicated power cell, water, salts, and electrical components incased within a metal shell can hold a charge for a reasonably long time while being durable. However, since the magnetic field storm, they've come to be a bit more fragile. We've yet to find a solution, but this planet will need more power cells, and such a new alternative way of crafting them has been made available to all settlers.