It actually is just a theory to have perpetual motion you have to have a frictionless setup and as we all know friction it everywhere ESP when creating electricity so until some on can get rid of friction it's is just a theory
im not trying to get perpetual motion just an extra boost of power and perpetual motion isnt a complete theroy its just incredibly hard to get right
All you people talking about perpetual motion as a theory theory don't have a clue. A theory is based on scientific evidence that can be repeated and peer reviewed. It has higher truth than facts, and is where calling something just a theory is where a lot of people (Religion) get it wrong when trying to state a case.
Perpetual motion is NOT a Theory or even a Hypothesis
Anyway the answer to the OPs question is a series/parallel switch, 2 batteries of the same voltage and capacity wired through a switch that can swap the batteries from parallel to series connection
Nick