The solar panels, charge controller, and batteries all deal with DC electricity. If we want to use anything that runs on AC, we need an inverter—a glorified transformer. Since I would just be charging my electronics, not trying to run power sucking things like microwaves, air conditioners or Bridgeport milling machines, I figured this 400 Watt Cobra inverter would be more than adequate. And it has been. Zero problems. There’s really nothing more to say.